Energy Transformation in the Construction Industry: Integrating Renewable Energy Sources

Abstract

The development of the building sector to the use of renewable energy, more so in photovoltaic (PV) systems, is a great step toward enhanced environmental sustainability and improved energy efficiency. This study seeks to determine the economic, environmental, and operational effects of integrating a PV system into a Polish production plant for buildings. Case study methodology was followed with the help of actual operating histories and simulation modeling to present the estimates of carbon emission savings, cost savings, and power efficiency. Key findings illustrate that 31.8% of the business’s full-year supply of electricity is through the utilization of solar energy and that it saves as much as 10,366 kg CO₂ of emissions every year. The economic rationale of the system is provided in the form of a 3.6-year payback period against long-term savings of over EUR 128,000 in 26 years. This work also addresses the broader implications of energy storage and management systems on the basis of scalability and reproducibility of intervention at the building construction scale. This study provides evidence towards the requirement of informing decision-making by business managers and policy decisionmakers as a step towards the solution of issues of interest to the utilization of renewable energy at industrial levels towards world agenda harmonization for sustainability and business practice.

1. Introduction

The current environmental challenges are such that the modern world needs to be guided toward sustainable energy practices [1,2,3,4,5]. Greenhouse gas emissions are driving climate change through rising temperatures, sea level increases, and intensified weather events that pose threats to both ecosystems and economies [6,7,8]. The gradual depletion of fossil fuel resources further amplifies the urgency for transformation within the energy sector. As has been illustrated, renewable energy technologies pave the way to low-carbon, sustainable energy solutions [9,10,11,12,13,14]. More specifically, photovoltaic systems have become one of the most important means of reducing dependence on non-renewable resources [15,16,17]. The construction sector, a significant consumer of energy and an emitter, has given a wide arena to these renewable technologies for their application in bettering efficiency and environmental performance. It has thus been effective in the adoption of PV systems, reducing carbon footprints and operational costs [18,19,20].

These systems will provide clean energy and, simultaneously, offer opportunities for energy storage and management that can further optimize consumption patterns [21,22,23,24]. This will be part of wider economic and environmental imperatives from which greater industrial growth and social well-being can be expected. In spite of extensive developments in renewable energy resources [25,26], there exists some lacuna in the knowledge regarding the application of renewable energy within specific industrial sectors like the construction industry [27,28,29,30,31]. This paper tries to fill this knowledge gap by assessing the financial, environmental, and operational impacts of photovoltaic installations in construction enterprises. It further evaluates cost savings, return on investment, and long-term profitability, thus providing a roadmap for sustainable energy adoption. Nowadays, renewable energy systems, such as photovoltaic technologies integrated into industrial processes, are receiving wide attention from both scientific interest and economic operators since the issues of sustainability and reduction of carbon footprints seem to have become highly relevant [32,33]. There are many studies concerning finding the economic and environmental benefits included in adopting renewable sources of energies within manufacturing processes [32,33,34,35,36,37,38,39,40,41]. Most of these studies primarily highlight direct energy cost reduction and associated environmental benefits, especially regarding CO₂ emissions [35,36,37,38]. Several researchers have consistently raised the role that could be played by PV systems as a cost-effective energy solution, mainly for energy-intensive sectors such as construction [39,40]. Key contributions include the study of grid dependency reduction, the associated economic savings, and the long-term viability of such investments. Some have focused on implementing EMSs, which help to optimize the consumption of generated energy and therefore increase the general energy efficiency of the enterprise.

One of the important themes behind the global movement toward sustainable industrial practice is the theme of resilience. In an energy transition context, resilience implies more than technological robustness; it entails economic agility, environmental viability, and operational continuity in the long term. This paper is directed at enhancing the level of resilience through efforts at the integration of renewable energy—photovoltaic systems—into the building sector. As sectors are faced with increasing energy market volatility, tightening environmental regulations, and the intensifying prevalence of climate-induced disruptions, resilience emerges as a core principle of sustainable development. In accordance, not only does the use of renewable energy minimize environmental impact, but it also makes companies more resilient and able to absorb system shocks and adapt to evolving socio-economic trends [42,43].

Most of the previous studies in this area dwell on one aspect of integrating renewable energy, be it economic savings, improving energy efficiency, or reducing environmental impact, and cannot take full account of the comprehensive and interlinked benefits brought in by the combined adoption of PV (photovoltaic) systems and their complementary technologies, such as EMSs (energy management systems) and energy storage solutions [36,37,38,39,40,41]. It is regarding such relations that a problem exists, as, while various case studies have been presented on different geographical locations, there has not been much research carried out to establish such relations specific for sectors concerned with energy consumption and the associated costs in the building and construction industry.

This paper presents an interesting insight into the financial, operational, and environmental advantages resulting from PV systems integrated into the building and construction industry by exploring the case related to a manufacturing company in Poland. The added value the system can provide is assessed; not only the short-term financial returns from the lesser consumption of electricity, but also its contribution to the return on investment in the long run, the stability during peak periods, and even its ability to generate extra revenue via potential sales back to the national grid. This paper also examines how the integration of renewable energy systems surpasses energy savings, diving into the field of operational efficiency through the optimization of energy usage with the assistance of advanced EMSs and energy storage technologies. The holistic approach gives a more fine-grained view of the wider effects of adopting renewable energy. In particular, the latter point contributes to the recent burgeoning literature in view of its applicability in industry.

1.1. Study Objectives

The present research has sought to provide, importantly, a valuable overview of what contributions can be made towards set targets in the meeting of economic resilience and sustainability with solar energy by focusing on the highly energy-consuming and carbon-intensive construction sector. This is, therefore, an attempt to address a research gap by connecting energy management and renewable energy adoption to sustainability practices within a sector that has remained in the blind spot of the greater renewable energy discourse. Such an approach is novel and relevant at the same time, offering important lessons for policymakers, industry leaders, and researchers interested in the future of sustainable practices in construction and manufacturing.

On the basis of this, it can be stated that this development of renewable energy systems, with a special focus on the use of photovoltaic technology in the construction sector, represents one of the key gaps in the existing research literature [39,40,41,44,45,46,47]. Though there has been considerable focus on the use of renewable energy in industries, few investigations into the construction industry explore the specific financial, environmental, and operational effects that come with adopting renewable energy. This paper tries to fill this gap by providing a detailed analysis of how photovoltaic systems could reduce carbon emissions, lower the cost of electricity, and enhance energy efficiency in construction enterprises. It also contributes to the knowledge of understanding the economic aspects of these systems by providing an all-rounded financial evaluation comprising cost savings, return on investment, and long-term profitability.

This article aims to outline the financial advantages that a manufacturing company in the construction sector could experience from energy transformation.

1.2. Research Questions

In this research, the authors seek answers to the following research questions:

• RQ 1: To what extent can the integration of renewable energy reduce carbon dioxide emissions?
• RQ 2: How does the adoption of photovoltaic systems impact electricity cost reduction in the construction industry?
• RQ 3: What are the financial implications of integrating solar energy into manufacturing processes in the construction sector?
• RQ 4: To what extent does the implementation of renewable energy systems improve the energy efficiency of enterprises in the construction sector?

This article’s format is as follows: Section 2 provides an overview of the building construction industry’s environmental footprint and energy needs and points out the most significant contributions that can be made by embracing solar energy solutions. Section 3 presents the methodology of this paper. Section 4 presents the international best practices of innovative construction and building material multinational corporations—Saint-Gobain, Skanska, and LafargeHolcim—highlighting various approaches to embracing renewable energy. Section 5 describes a simulation exercise conducted for the Polish manufacturing company and presents data regarding energy consumption statistics, PV design, performance and financial measures, and modelling. Section 6 presents a critical analysis of the results in the context of global trends on energy transformation, lifecycle thinking, and contribution of energy management and energy storage technologies. Section 7 deals with conclusions drawn from research, policy, industry practices, and research implications.

2. Literature Review

The main goal of this section is to establish the critical importance of solar energy in the transition toward sustainability within the construction industry. It highlights the sector’s significant contribution to global energy consumption and CO₂ emissions, emphasizing the urgency of adopting renewable energy sources like solar power. The text provides a comprehensive context, showcasing solar energy as a transformative force that addresses environmental, economic, and energy security challenges. By illustrating the benefits of integrating solar panels into buildings—such as reduced dependence on fossil fuels, cost savings, energy independence, and decreased carbon footprints—it aligns with global efforts to combat climate change and transition to a greener economy. Furthermore, this section acknowledges existing hurdles like upfront costs and technological complexities but points to advancements that enhance the viability and appeal of solar energy solutions, supported by studies validating their environmental benefits.

Solar energy has emerged as a driving force behind the rapid adoption of renewable energy. Its widespread application in industries, residential housing, and commercial spaces has yielded significant energy savings, making it a cornerstone of sustainable development efforts [48,49]. The construction sector, a complex and multifaceted industry, encompasses various stages, including building material production, construction, operation, and demolition [50,51,52]. This sector is a critical focus for renewable energy initiatives due to its significant environmental impact. According to the International Energy Agency, the building sector accounts for one-third of global energy consumption and nearly 40% of global CO₂ emissions [53]. In 2019, CO₂ emissions from buildings reached an unprecedented 10 GtCO₂, driven by rising demands for heating, cooling, and other energy-intensive systems exacerbated by extreme weather events [54]. These emissions contribute heavily to global warming and climate change, with profound effects on ecosystems and human communities. Addressing these challenges requires urgent measures to enhance building energy efficiency and increase clean energy production, priorities already reflected in new building regulations across Europe [55,56].

Energy is a pivotal driver of economic progress, with electricity production and consumption underpinning sustainable economic development [21]. The global shift toward a “green economy” emphasizes the efficient use of energy and the replacement of fossil fuels with renewable energy sources. This transition from non-renewable energy systems to ones based on renewable and low-carbon sources is reshaping key sectors such as transportation, industry, power, and construction [57]. Central to this effort is the goal of reducing greenhouse gas emissions and minimizing environmental harm. Achieving this vision demands a concerted effort involving governments, private sector stakeholders, and the public, along with the advancement of innovative technologies that support sustainability [58]. By aligning energy demand with environmental protection, the global movement toward a green economy aspires to create a development model that addresses both contemporary environmental concerns and social requirements [59].

The construction industry is at the forefront of this transformation, with solar energy playing a leading role. Solar energy is reshaping the built environment and paving the way for a greener, more energy-efficient future [60,61,62]. Solar panels have gained popularity within the construction sector due to their ability to convert sunlight into clean, usable electricity [63]. As concerns about climate change and environmental degradation escalate, architects, developers, and policymakers are increasingly turning to solar energy as a reliable and effective renewable resource to reduce greenhouse gas emissions [64]. Solar panels offer the advantage of generating electricity on-site, allowing buildings to meet a significant portion—or even all—of their energy needs. This capability reduces dependency on traditional electricity grids, lowers utility costs, and enhances energy independence [65]. Moreover, through “net metering”, buildings equipped with solar panels can return surplus energy to the grid, receiving credit or compensation for the excess energy produced [66]. This mechanism enhances the self-sufficiency of buildings and supports the development of a resilient, decentralized energy system.

In addition to its economic benefits, integrating solar panels into construction offers significant environmental advantages. By harnessing solar power, buildings can drastically reduce their carbon footprints, mitigate air pollution, and conserve finite fossil fuel resources. These benefits align with global initiatives to combat climate change and transition to a carbon-constrained future [67]. However, the widespread adoption of solar panels in construction is hindered by challenges such as high upfront costs and installation complexities. Despite these barriers, advancements in technology and economies of scale have improved the long-term viability of solar energy solutions, making them increasingly attractive investments [68].

The environmental benefits of solar energy extend to the manufacturing of photovoltaic (PV) cells. Tsang et al. [69] analyzed the environmental impact of organic PV cells compared to conventional silicon solar cells, finding that organic PV cells have a lower environmental footprint and shorter energy and carbon payback times. For long-term and short-term applications, organic PV cells exhibited environmental impacts 55% and 70% lower than those of silicon devices, respectively. Similarly, Oteng et al. [70] investigated the environmental impact of monocrystalline and multicrystalline silicon solar panels in Australia. Their findings revealed significant reductions in global warming potential under mandatory product management scenarios, with mono c-Si modules achieving a potential of −1 × 10⁶ kgCO₂eq and multi c-Si modules reaching −2 × 10⁶ kgCO₂eq.

This section underscores the transformative potential of solar energy in the construction industry, emphasizing its economic, environmental, and operational benefits. By overcoming existing challenges and leveraging technological advancements, solar energy can continue to drive the sector toward a sustainable and resilient future.

3. Methodology

This study used a data-based case study approach to estimate the financial, operational, and environmental impacts of the installation of photovoltaic (PV) systems at a Polish construction product manufacturer. The approach mixed real-world operation data, simulation modeling, and economic analysis in the assessment of the feasibility and benefits of integration of solar energy solutions into the energy system of the company. This approach was designed not only to quantify the short-term effect of PV integration but also to simulate long-term effects under varied operating conditions. The research methodology is presented in Figure 1.

3.1. Data Collection

Actual electricity consumption and cost data gathered during three years (2021–2023) from the host factory were the source of the data directly. Gross and net electricity costs and monthly and yearly energy consumption were monitored and provided to enable trend observation and the establishment of baseline levels. Such data also contributed significantly to gaining experience with the firm energy use pattern, e.g., variability within cycles affecting energy demand and PV system efficiency.

Besides consumption data, studies provided detailed technical details of the expected photovoltaic plant, i.e., generator capacity, inverters, and panel numbers, surface area, and performance parameter estimation. Floor plans of the manufacturing building and PV panel arrangements were utilized to achieve spatial feasibility and optimal orientation.

3.2. System Design and Simulation Modelling

The PV system was designed according to normal engineering practice, national standards, and manufacturers’ recommendations. The computed system comprised a cumulative capacity of 22.89 kWp in 42 units of solar photovoltaic panels, supplied from a single inverter. The size needed for the generator was around 108.5 m². An operating model of the PV system was thus established with these parameters to quantify the annual energy produced, self-consumption, export of surplus to the grid, and related CO₂ emissions savings.

Simulations were made with deterministic models to predict system performance under typical Polish climatic conditions. Performance parameters such as the annual yield (963.52 kWh/kWp), performance ratio (86.4%), and shading loss (1.7% annually) were derived from irradiance, equipment efficiencies, and site limitations. The models also considered an inverter standby load of 13 kWh/year.

In order to determine economic feasibility, a finance simulation was carried out using the actual electricity prices, investment, VAT parameters, and forecasted feed-in tariff for compensation. The most important parameters like return on investment (ROI), net present value (NPV), payback period, cost per generated kWh, and cash flows over a 26-year operational life were calculated.

3.3. Energy Flow and Consumption Scenario Analysis

The plan also included creating energy flow models to quantify and display energy interactions between the PV system and the grid. Scenarios were simulated to allow for different levels of self-consumption and grid utilization. One of the fundamental scenarios simulated the company’s 2023 electricity consumption profile, which was modified to incorporate PV integration. This calculation revealed that 6741 kWh (30.5%) of the energy required will be provided directly from the PV array and the remaining 14,461 kWh will be taken from the grid.

This simulation also brought out the time mismatch in solar energy generation (peaks during the daytime) and commercial power consumption (distributed over daytime and nighttime). In the absence of battery storage, this time mismatch results in surplus energy being returned to the grid (15,327 kWh/year), which in this simulation was utilized as part of profitability through net metering or payment agreements with the grid.

3.4. Profitability Analysis

A thorough profitability study was conducted by projecting cash flows for 26 years. The model considered falling remuneration rates, further savings on grid electricity, losses of PV efficiency due to age, and rises in energy prices. The initial investment is approximated to be EUR 22,698.83 (23% VAT included). The cost of energy generation annually is approximated to be 0.04 EUR/kWh.

Key conclusions of this study were a payback period of 3.6 years, year 26 total cash flow of EUR 128,162.26, and return on the whole investment of 28.64%. The simulations confirmed the long-term economic feasibility and strength gained from the PV system in favor of investment in renewable energy for energy-using sectors like the building industry.

4. Examples of Implementation in the Construction Industry

Saint-Gobain, Skanska, and LafargeHolcim were chosen as representative examples of energy transformation in the construction sector due to their prominent global presence, leadership in sustainability initiatives, and innovative approaches to renewable energy integration. These companies are industry pioneers with a track record of implementing advanced energy strategies, making them ideal benchmarks for analyzing the impact of renewable energy solutions on the construction industry. Saint-Gobain is a recognized leader in building materials, operating in over 70 countries and consistently ranking among the top companies in sustainability indexes. Skanska, a major player in construction and infrastructure, is known for integrating cutting-edge energy solutions in high-profile projects worldwide. LafargeHolcim, a global leader in cement and building materials, has been at the forefront of combining renewable energy use with sustainable resource management.

4.1. Saint-Gobain—Leader in the Integration of Renewable Energy Sources

Saint-Gobain, a recognized global leader in building materials, consistently implements renewable energy strategies to reduce its carbon footprint and increase energy efficiency. The company invests in various renewable energy technologies, such as photovoltaic installations, biomass-based heating systems, and effective energy management systems. These initiatives not only reduce CO₂ emissions but also enable Saint-Gobain to achieve sustainable development and meet the challenges of global energy trends.

The company installed photovoltaic panels on the roofs of its production plants, which allows for significant solar energy generation. An example is a production plant in the Netherlands, where photovoltaic panels meet 40% of the annual energy demand. This investment not only reduces energy consumption from traditional sources but also contributes to reducing carbon dioxide emissions, supporting the company’s sustainable development goals. Additionally, the installation of photovoltaic panels in Saint-Gobain’s production plants is an example of their commitment to the development of renewable energy and the effective management of energy resources at a global level. Additionally, in some locations, Saint-Gobain uses wind energy, which contributes to even greater reductions in CO₂ emissions. The company has implemented advanced energy management systems that monitor and optimize energy consumption in real time. Thanks to this, the company is able to control its energy consumption more effectively and reduce waste.

4.2. Skanska—Green Construction and Renewable Energy

Skanska is an international construction company that operates on the global market, specializing in the implementation of various construction projects around the world. Skanska is known for its involvement in commercial, infrastructure, and residential construction, offering comprehensive solutions from design concepts to final implementation. Skanska not only builds modern office buildings, shopping centers, and public facilities but also expands existing infrastructure and implements sustainable housing projects adapted to modern ecological and energy standards.

The company goes beyond standard approaches to project implementation, placing great emphasis on sustainable development and innovative energy technologies. It specializes in the design and construction of facilities that strive for zero energy consumption, engaging in the creation of commercial, infrastructure, and residential buildings around the world.

An example of their commitment to sustainable technologies is an office building in Seattle (Stone34), which is a great example of innovative energy solutions. This building is fully energy self-sufficient thanks to the use of photovoltaic panels that generate electricity from solar radiation and geothermal systems for efficient heating and cooling. This approach not only reduces the need for traditional energy sources but also minimizes CO₂ emissions and the costs associated with maintaining the building for a long period of time.

Skanska is constantly exploring new technologies and construction practices that allow for the creation of more efficient and ecological facilities. Their commitment to the development of zero-emission projects is an inspiration for the entire construction industry, demonstrating that innovative solutions can be key to achieving sustainable development goals and reducing the environmental impact of buildings on their surroundings.

4.3. LafargeHolcim—Use of Biomass and Solar Energy

LafargeHolcim is a global leader in the production of cement, concrete, and other construction materials, known for the wide use of innovative technological solutions and a sustainable approach to industrial activities. The company not only produces building materials on a global scale but also actively engages in sustainable development and CO₂ emission reduction initiatives. The company undertakes a number of activities aimed at reducing the impact of its activities on the environment. An example is the use of advanced technologies in production processes which enable more efficient use of raw materials and energy and minimize carbon dioxide emissions. Additionally, the company also invests in research on innovative solutions, such as alternative raw materials and emission reduction technologies, to introduce even more ecological solutions into its production.

The company invested in the construction of photovoltaic power plants on the premises of its production plants. An example is the plant in Metapán, El Salvador, where solar panels generate much of the electricity needed. The photovoltaic park consists of over 39,000 solar panels and generates 17 MW of clean energy. A solar park is currently under construction at the Nagarote plant in Nicaragua which will provide approximately 40% of the electricity required by the plant. Additionally, the first floating photovoltaic power plant is planned in Belgium in cooperation with Total Energies which will provide renewable energy corresponding to 15% of the total electricity demand of the Obourg cement plant from 2024.

Additionally, LafargeHolcim uses biomass as an alternative energy source in its cement plants, which is a key element of its CO₂ emission reduction and sustainability strategy. It actively strives to reduce the consumption of fossil fuels by replacing them with locally sourced biomass, which helps to reduce the carbon footprint of the entire production process.

An example of the effective use of biomass energy solutions is a production plant in France. In this plant, biomass is used to power cement kilns, which helps reduce CO₂ emissions and reduce the consumption of traditional energy sources. Locally obtained biomass, like wood or agricultural waste, is an ecological alternative energy raw material that not only reduces dependence on fossil fuels but also supports the development of local economies and contributes to the sustainable development of the regions where the company operates.

While the utilization of biomass as an alternative source of energy brings immense potential from a point of view of a reduction in CO₂ emissions and decreased dependence on fossil fuels, some risk is also associated with it. The greatest risks associated with biomass energy probably stand particularly in that place where the practices for sourcing biomass have to be sustainable. Most especially, biomass sourced from wood, agricultural waste, or other plant materials could well act as a source of deforestation and degradation when not managed well. With improper reforestation policy and guidelines for land use, the constant demand for biomass will then deplete natural resources through the loss of forests and of biodiversity, disrupting the local ecosystem. This would defeat the very purpose of using biomass, as the absorption potential of forests could be diminished and contribute negatively towards the worsening of climate change instead of improvement [47].

The use of reforestation policies would keep biomass energy viable for a longer period. Any biomass re-growth policies should be based on the premise of providing a balance between biomass cropping and the re-growth in the forests [71]. That is where, in the case of replanting trees, they can maintain a carbon sink only when the replanting occurs at a compensatory rate for the trees that have been taken from the forests. The circle of biomass energy itself could be even a net carbon emitter, once these post-processing emissions of extraction and transport are put into the balance, outweighing the avoided emissions that would have been made by the use of fossil fuels [72,73,74].

Biomass sourced from agricultural wastes and other organic wastes also need serious attention. The trend in the use of agricultural residues for biomass production may eventually lead to issues of food security and impinge on local food systems. Without proper regulation, competition may arise between food production and energy requirements when a diversion of agricultural wastes is made for energy generation in locales where food supply is already stretched [75].

Another problem is land-use change associated with biomass production. Large plantations of biomass may imply changes in habitat, reductions in biodiversity, and alterations in land use patterns which may not be congenial to environmental concerns. Care must be taken so that the carbon footprint for the change of the natural ecosystem into one of biomass plantation does not result in environmental degradation due to injudicious judgment [76,77].

If biomass energy is really to be sustainable, then companies like LafargeHolcim will have to make sure that the sourcing of biomass conforms to the best practices for sustainability: it needs to support local reforestation efforts, manage agricultural waste in a responsible way, and develop systems for monitoring the long-term environmental impacts of biomass harvesting. If such care is not taken, promising as biomass may be, its use could be unwittingly adding to environmental degradation rather than being the sustainable solution it is often presented as [42].

Thanks to these initiatives, LafargeHolcim has managed to significantly reduce CO₂ emissions by millions of tons per year and significantly reduce energy consumption. It is currently considered a leader in the field of sustainable production of building materials thanks to the use of innovative technologies and sustainable development strategies. Switching to the use of biomass energy sources in cement plants, such as locally sourced biomass, is a key element of their strategy. Thanks to this, LafargeHolcim not only reduces CO₂ emissions but also minimizes the negative impact on the environment by limiting the consumption of fossil fuels. Additionally, it invests in effective production technologies that enable it to achieve higher energy efficiency and reduce the consumption of natural resources. Summarizing the information contained in the examples of implementation in the construction industry, it highlights significant renewable energy initiatives undertaken by Saint-Gobain, Skanska, and LafargeHolcim, providing detailed context and data to demonstrate the broader impact of these efforts. These companies serve as exemplary models within the construction sector, showcasing innovative approaches to sustainability through the integration of renewable energy technologies. Saint-Gobain has made notable advancements by installing photovoltaic (PV) panels across multiple facilities, including a plant in the Netherlands where solar energy meets 40% of annual energy needs. This initiative not only underscores the company’s commitment to renewable energy but also demonstrates the scalability of such projects. Over the past decade, Saint-Gobain has achieved a remarkable 20% reduction in CO₂ emissions, highlighting the effectiveness of its strategies and the broader environmental benefits of transitioning to cleaner energy sources. Skanska, another leader in the construction sector, has implemented zero-energy commercial buildings such as the Stone34 building in Seattle. This project achieves complete energy independence by utilizing solar and geothermal systems, setting a benchmark for sustainable building practices. Additionally, Skanska has deployed mobile PV panels at construction sites which have significantly reduced dependency on fossil fuel generators. These mobile solutions have lowered operational CO₂ emissions by 30% at select projects, reflecting the company’s innovative approach to managing energy in dynamic environments. LafargeHolcim has demonstrated its leadership by developing a 17 MW solar power plant in El Salvador, generating 39,000 MWh of clean energy annually. This initiative meets approximately 40% of the plant’s energy needs, substantially reducing its reliance on traditional energy sources. Furthermore, the company has pioneered the use of biomass in cement production, which has led to a reduction of over 2 million tons of CO₂ emissions per year globally. These efforts illustrate LafargeHolcim’s significant contributions to sustainable practices within the energy-intensive cement industry.

When compared to industry standards, the strategies adopted by these companies surpass typical renewable energy integration levels. While the construction sector globally remains heavily reliant on fossil fuels, these firms demonstrate the feasibility and economic advantages of transitioning to renewables. For instance, LafargeHolcim’s extensive use of biomass in cement production represents one of the most comprehensive applications of alternative energy in the industry, setting a high benchmark for competitors.

The energy strategies of these companies offer valuable insights. All three integrate renewable energy within broader operational frameworks, utilizing advanced energy management systems (EMSs) to optimize energy consumption and manage variability through storage technologies. These initiatives also exhibit scalability, as seen in Saint-Gobain’s ability to replicate PV solutions across multiple facilities in various countries. Moreover, the economic and environmental returns are substantial; Skanska and LafargeHolcim report significant reductions in operational costs and an improved return on investment (ROI), alongside meaningful environmental benefits. These accomplishments reinforce the potential for renewable energy to drive both economic and environmental progress in the construction sector.

5. Results

The following section presents the results of the simulation conducted for the implementation of a photovoltaic (PV) system in the analyzed manufacturing company operating within the construction sector. The analysis covers technical, economic, and environmental aspects of the system’s integration. Simulation, in the context of implementing renewable energy sources in a construction manufacturing company, is the process of modeling and analyzing various scenarios related to the introduction of new energy technologies and infrastructure. It is a type of tool that allows simulating the behavior of the energy system under the influence of changes, such as the addition of new energy sources or changes in consumption or market conditions. It involves creating a model that takes into account various factors such as energy consumption, production, greenhouse gas emissions, weather conditions, energy prices, regulations, etc. This is followed by a series of simulations to understand what the effects of making changes to the system will be and what the costs and benefits will be. In short, simulation is an analytical tool that helps companies better understand the consequences of implementing renewables and make more informed, data-driven decisions. When simulating the implementation of renewable energy sources in a manufacturing company, focus is placed on the following phases (Figure 2).

As outlined in Figure 2, the simulation process for the implementation of renewable energy sources includes several key stages: data collection, system design, risk identification, simulation execution, and result analysis. Among these, the risk identification phase plays a crucial role in ensuring the technical, financial, and operational viability of the photovoltaic (PV) system. This phase involved a comprehensive assessment of potential risks associated with deploying solar technology in the manufacturing facility. First, a technical assessment of the environment was conducted, evaluating factors such as roof shading, panel orientation, component quality (e.g., inverters and PV modules), and exposure to weather conditions like snow, ice, and rainfall. Second, operational risks were identified, including the integration of the PV system with the factory’s electrical infrastructure, possible production downtime during installation, and the need for personnel training to manage and monitor the system. Third, a regulatory and financial risk analysis was undertaken, accounting for fluctuating energy prices, evolving policies around feed-in tariffs or net metering, and potential delays in securing administrative permits. The fourth element focused on the life cycle of the system, considering panel degradation rates (estimated at 0.5–1% annually), maintenance requirements, and risks of equipment failure due to mechanical damage or electrical surges. The local climate was also analyzed, highlighting reduced solar generation during winter months and the potential mismatch between solar production and the company’s energy consumption profile. Lastly, the absence of an energy storage system was recognized as a limiting factor, as surplus electricity is fed back into the grid, reducing the system’s self-consumption rate (approximately 30.5%) and affecting investment efficiency. Together, these detailed risk factors were integral to accurately simulating and optimizing the renewable energy implementation strategy.

The data on electricity consumption and associated costs for the past three years, as presented in

Table 1. Energy demand of the analyzed company. Source: developed by authors.

	Consumption
Year 2021	17,435 kWh		Gross value	EUR 6451.40
Year 2022	20,607 kWh		Gross value	EUR 7721.93
Year 2023	Consumption	Net value	Gross value
January	2710 kWh	EUR 888.52	EUR 1092.89
February	2233 kWh	EUR 737.36	EUR 906.95
March	1968 kWh	EUR 663.68	EUR 816.33
April	1640 kWh	EUR 560.75	EUR 689.72
May	1290 kWh	EUR 453.16	EUR 557.39
June	1197 kWh	EUR 431.70	EUR 531.00
July	997 kWh	EUR 359.57	EUR 442.28
August	1384 kWh	EUR 463.49	EUR 570.10
September	1500 kWh	EUR 502.34	EUR 617.88
October	1725 kWh	EUR 492.86	EUR 606.22
November	1260 kWh	EUR 531.43	EUR 653.66
December	2685 kWh	EUR 754.57	EUR 928.12
Total	21,189 kWh	EUR 6839.44	EUR 8412.52

, were obtained directly from the records of the analyzed Polish manufacturing company operating within the construction industry. This dataset provides a detailed overview of the company’s energy usage patterns, highlighting the scale of electricity consumption and the financial burden associated with meeting its energy needs. The inclusion of this data is critical to understanding the current energy demands of the enterprise and serves as a foundation for evaluating the potential benefits of integrating renewable energy solutions, such as photovoltaic systems. By examining historical trends in energy consumption and expenditure, this analysis enables a more accurate projection of the financial and operational impact of transitioning to more sustainable energy practices.

Table 1 shows the trend of energy consumption by a company over three years, from 2021 to 2023, with months specified for the year 2023. The table also gives both gross and net values of energy costs, hence capturing the financial and operational dynamics of energy use at this firm. While in 2021 the company used 17,435 kWh, translating to a gross energy cost of EUR 6451.40, this went up in the year 2022 to 20,607 kWh, with the associated gross value rising to EUR 7721.93. This indicates an increasing trend, which may mean that the expansion of the production process of the company or an increase in the scale of operation during the period was thus requiring more energy. It is most likely that this upward consumption of energy mirrors inflationary trends or increased prices of energy that contribute to the cost increase. That is to say, the increase in energy consumption may reflect more intensive activity on the part of the company, probably because more products or services are demanded.

The forecast for 2023 becomes much more detailed, and the month-by-month energy consumption is seen together with the cost. Whereas in January, the company consumed 2710 kWh (EUR 1092.89 gross value), in December consumption was higher and reached 2685 kWh, giving the gross cost of EUR 928.12. Energy consumption in the analyzed company presents quite typical seasonal variations of the monthly energy consumption. Normally, energy demand for companies is higher during colder months—for example, January and December—due to either the operation of heating applications or increased operations related to end-of-year targets. This makes the consumption lower during the months of June and July because of reduced intensity or reduced operations, since the demand for heating is at a minimal rate during this summer period. The gross value of energy costs also varies from one month to another, with the variation largely being dictated by the fluctuation in energy consumption. Another interesting point here is that consumption has always been higher during the cold months when either the need for heating or lighting is greater. The values peak in December, corresponding to the seasonal variation of demand for electricity, particularly in those months when low temperatures increase heating or lighting demand. The other difference that exists between net and gross relates to the adjustments included concerning energy tariffs, applicable taxes, or subsidies. Whereas the gross value represents full cost for energy with no kind of deductions or adjustments having been carried out, the net value probably includes discounts or financial incentives that are actually being paid by the real company. The total for 2023 is 21,189 kWh, valued at EUR 8412.52. This continues the upward trend of energy consumption by the company and is higher than the previous totals. The overall gross value would indicate that the company is in a position whereby its energy costs are increasing, possibly due to general market factors such as inflation and increased energy costs.

The data in Table 1, in general, indicate an upward trend of consumption over time, since recorded seasonal variations for monthly consumptions are insignificant. This shows how expensive energy consumption is to the company, where the growing cost over three years corresponds to the increased consumption. The level of energy use is dependent not only on external variables like the prices of energy but also from within through the levels of production activity and seasonal adjustment. Such knowledge will be important to such firms in devising energy management strategies as a mitigant against spiraling costs. It would also serve to understand the energy consumption pattern in pinning periods of inefficiency or further areas where energy-saving measures can be introduced through renewable energy solution adoptions, energy-efficient technologies, or more refined operational practices.

In the analyzed company, a consistent upward trend in electricity usage, increasing by several percent each year, has been recorded. This growth leads to rising operational expenses, highlighting the necessity for efficient energy management and the search for alternative options, such as the integration of renewable energy sources, to maintain financial stability. To better understand and effectively tackle these escalating costs, the company carried out a simulation focused on the implementation of renewable energy. This approach enables forecasting the impacts of growing electricity demand and supports the identification of optimal solutions to mitigate the associated financial burden.

Table 2. Projection of investment expenses. Source: developed by authors.

ID	Investment Cost
1	Net price	EUR 18,454.33
2	Tax 23%	EUR 4244.49
3	Gross price of the entire investment	EUR 22,698.82

shows a financial breakdown for the proposed investment in a photovoltaic panel system tailored to a manufacturing firm operating in the construction sector. It details both the net installation cost and the 23% value-added tax (VAT), ensuring a comprehensive view of the total investment outlay. Including both components allows the company to make precise financial projections and strategically plan for the introduction of the photovoltaic system.

After a thorough analysis of the roof project of the production hall, depicted in Figure 3, a photovoltaic installation project was proposed, as presented in Figure 4. This project precisely defines the arrangement of photovoltaic panels and their quantity, which constitutes a crucial element of the renewable energy implementation plan in the company.

Figure 5 illustrates a detailed technical layout of the photovoltaic system. The schematic provides thorough information about the electrical connections and all essential components, supporting a full evaluation and proper execution of the project. This extensive documentation facilitates the efficient installation of the photovoltaic system, ensuring compliance with the predefined design requirements.

Table 3. Specifications of the photovoltaic installation. Source: developed by authors.

ID	Grid-Connected Photovoltaic Installation (PV)
1	PV generator power	22.89 kWp
2	PV generator area	108.5 m2
3	Number of PV modules	42
4	Number of inverters	1

provides essential information about the photovoltaic system, detailing aspects such as the generator’s power output, the total surface area, the quantity of photovoltaic panels, and the number of inverters. These fundamental parameters are crucial for assessing the system’s efficiency, properly sizing the installation, and estimating potential investment returns.

The analysis of data pertaining to the proposed photovoltaic installation enables a comprehensive assessment of its performance potential and its anticipated impact on the company’s operational framework. Such an analysis facilitates the determination of key performance indicators critical for evaluating the system’s efficiency and financial viability. Primarily, the assessment of energy output allows for the estimation of electricity generation over a defined period, which constitutes a fundamental metric for forecasting cost savings and assessing contributions to the company’s overall energy profile. Furthermore, the evaluation of self-consumption rates and the volume of surplus energy supplied to the grid provides insight into the company’s degree of energy autonomy and the prospective revenues derived from energy sales. The proportion of self-utilized solar energy and its contribution to total energy demand are essential for understanding the economic and environmental implications of renewable energy integration. Moreover, indicators such as annual energy yield and the performance ratio serve as measures of the photovoltaic system’s operational efficiency, supporting comparisons between actual outcomes and projected expectations. Decreased efficiency due to shading and CO₂ emissions that can be avoided are aspects related to the operation of the installation under varying environmental conditions and the benefits to the environment through reducing greenhouse gas emissions. All relevant data have been systematically gathered, analyzed, and compiled in

Table 4. Profit from renewable energy sources. Source: developed by authors.

ID	Profit
1	Energy produced by the PV system (AC grid)	22,068 kWh
2	Own consumption of energy directly	6741 kWh
3	Energy returned to the grid	15,327 kWh
4	Adjustment at the point of supply	0 kWh
5	Share own consumption of energy	30.5%
6	Solar energy’s contribution to meeting demand	31.8%
7	Annual yield	963.52 kWh/kWp
8	Performance ratio (PR)	86.4%
9	Reduction in yield due to shading	1.7%/Year
10	Avoidable CO2 emissions	10,366 kg/Year

, providing a basis for the evaluation of the photovoltaic installation’s potential within the surveyed construction-sector manufacturing company.

What is shown here, therefore, includes not only the technical performance of the system but its broader ramifications for energy efficiency, sustainability, and financial savings as well. Closer analysis of the details within this table yields a few very important observations and some causes at the root of this success with renewable energy implementation. First, the total photovoltaic production amounts to 22,068 kWh annually. This represents the total energy produced by the system during the period, which is a significant contribution to the company’s energy demand. The figure indicates a great capability of the PV system in producing a considerable percent of the company’s total demand for electricity. Moreover, the amount of the produced energy underlines that from a technical point of view, the solar installation is efficient as an energy converter, so that it can be considered a truly useful resource for the same company. The main positive impact of such high generation of energy would be the savings of high costs of electricity, mainly during the daytime when the generation on account of solar power is higher.

Out of this total produced, 6741 kWh is consumed directly by the company. The energy used directly indicates the amount of self-sufficiency achieved by adding renewable energy in this process. As for its own consumption, by the energy produced on-site, it limits its demand for electricity provided from the grid, generally suffering fluctuating prices and uncertain supply conditions. The share of self-consumption, accounting for 30.5%, does also indicate that effective use is made of the energy generated by the solar system for the company to further the application of renewable energy and limit dependency on external energy providers to a minimum. This self-consumption, however, not only contributes to a reduction in the operational cost of companies but also enhances energy security, since the company is less exposed to the volatility of energy markets. From the table, what is observable is that there is a massive output from the PV system, 15,327 kWh being supplied back into the grid. Surplus export, in fact, is a critical factor in the whole profitability of the renewable energy installation. In this respect, the company will generate extra income or financial credits according to the applied regulatory framework by returning excess energy back into the grid. This represents an additional stream of revenue and therefore improves the total return on investment from the PV system. Additionally, selling excess energy back to the grid further stabilizes its financial position by introducing some level of predictability in revenues, thereby further consolidating its financial viability.

The PR explains just how efficient the overall system is in converting the captured solar energy into usable electrical energy. The high PR value of 86.4% would indicate that the respective PV system works in relatively efficient conditions, with limited energy losses in the process of conversion. This is a crucial indicator because it gives an account of the performance of the system under consideration against the maximum theoretical limit. The fairly high PR in this case means that this system operates effectively for energy savings and, hence, cost-effectiveness. On the other hand, however, it should be underlined that the portion of the energy yield reduced by shading amounts to 1.7% annually, which is slight but again raises questions about the placement and maintenance of the system to achieve maximum energy generated. Even limited shading can have a tangible effect on energy production, and efforts at minimizing shading or adjusting panel orientation could further improve the performance of the system.

The table also shows the environmental benefits of the PV system, with the avoidable CO₂ emissions being 10,366 kg per year. This reduction in CO₂ emissions is a very important environmental impact caused by transitioning to renewable energy sources. By displacing energy conventionally produced from fossil fuels, the PV system actively contributes to worldwide efforts to reduce the effects of climate change. The CO₂ savings are an important measure of the company’s commitment to sustainability and its alignment with broader environmental goals. Beyond that, the reduction of carbon emissions also serves to enhance the company’s image in the market, since sustainability is becoming one of the increasingly important factors that customers, investors, and regulators take into consideration.

The effectiveness of the solar energy system in meeting 31.8% of the total energy demand of the company further underscores its supportive role to the company’s operations. In contributing directly to energy consumption and displacing the need for grid-supplied electricity, the PV system enhances efficiency and sustainability in operations. In other words, the fact that a large part of the energy demand can be covered by a solar energy system means greater energy independence and long-term cost savings. This also constitutes a strategic move because of the reduced risks associated with surges in energy prices and uncertainty in supply, adding to the financial resilience of the company.

The simulation of the photovoltaic system’s operation, conducted on the basis of the previously collected data, facilitates a comprehensive evaluation of its performance and efficiency. Utilizing the parameters outlined in Table 4, it is possible to model various operational scenarios under differing weather and working conditions, enabling the assessment of energy production potential, the system’s impact on the company’s energy balance, and the estimation of savings and benefits resulting from the adoption of renewable energy sources. The outcomes of the simulation are presented in

Table 5. Simulation of plant operation PV. Source: developed by authors.

ID	PV Installation
1	PV generator power	22.9 kWp
2	Annual yield	963.52 kWh/kWp
3	Performance ratio	86.4%
4	Reduction in yield due to shading	1.7%/Year
5	Energy produced by the PV system (AC grid)	22,068 kWh/Year
6	Own consumption of energy	6741 kWh/Year
7	Energy returned to the grid	15,327 kWh/Year
8	Share own consumption of energy	30.5%
9	Avoidable CO2 emissions	10,366 kg/Year

.

Figure 6 depicts a graph illustrating the potential energy produced by the photovoltaic system, including the self-consumption by the manufacturing company and the energy returned to the grid.

The subsequent phase of the simulation focuses on illustrating a potential electricity consumption scenario for the preceding year, under the assumption that the company operated a photovoltaic installation. The analysis considers a total electricity usage of 21,189 kWh, including a standby consumption attributed to the inverter of 13 kWh. The photovoltaic system supplied 6741 kWh, while the remaining energy demand, amounting to 14,461 kWh, was met through the external power grid. The share of solar energy in covering the total demand amounted to 31.8%, highlighting the significant contribution of the photovoltaic installation to meeting the company’s energy needs. The entire simulation step is presented in

Table 6. Potential electricity consumption scenario. Source: developed by authors.

ID	Device
1	Device	21,189 kWh/Year
2	Standby consumption (inverter)	13 kWh/Year
3	Total consumption	21,202 kWh/Year
4	Consumption covered by PV	6741 kWh/Year
5	Consumption covered by the network	14,461 kWh/Year
6	Solar energy’s contribution to meeting demand	31.8%

and Figure 7.

The basic reason why so much electricity produced by the photovoltaic (PV) system is being supplied back to the grid—since the company’s annual energy consumption is slightly less than the PV output—is that there is a time mismatch between the generation and the consumption. PV systems generate electricity at some hours of the day, with the peak usually during noon, when solar irradiance peaks. Alternatively, the business’s power consumption is diversified throughout the day and, maybe, the late evening or early morning hours when solar production is at a minimum or nil. Therefore, in the case of high solar generation and minimum business internal load, the surplus power cannot be utilized on-site and, therefore, goes into the grid. On the other hand, during periods of no sunlight and inactivity of the PV system, the company will have to import electricity from the grid to support its operational demands. This explains why, even with an annual PV output that can theoretically cover its energy demands, the company still imports 14,461 kWh per year from the grid.

This is even more critical when there is no energy storage system, such as batteries, that may allow the company to store excess energy produced during the day for later use. In the absence of storage, self-consumption remains low—here approximated at 30.5%—since the company can only utilize electricity upon generation. All excess energy needs to be exported and any shortage during non-generating periods needs to be covered through import from the external grid. In a bid to reduce use of the external grid and optimize energy independence, the company would need to establish the right mechanism of storage or shift its working timetable to be compatible more often with the operation timetable of solar power. In the meantime, exporting excess electricity into the grid is both technologically required and an economically efficient system, particularly under a feed-in tariff or net metering schemes.

The energy flow diagram depicted in Figure 8 illustrates the principal processes of energy distribution within the manufacturing company, considering the integration of the photovoltaic system. The installation generates 6741 kWh of electrical energy, which is utilized internally to support various operational needs. Nevertheless, due to the variability inherent in solar energy production, the company is required to supplement its energy demand by sourcing additional electricity from the external grid during periods of insufficient photovoltaic generation. Consequently, 6741 kWh of energy is supplied by the photovoltaic system, while 14,461 kWh is drawn from the grid, resulting in a total annual electricity consumption of 21,189 kWh. The presented diagram facilitates a comprehensive understanding of the photovoltaic system’s role in balancing the company’s energy requirements and its interaction with the external power infrastructure.

Forecasting energy consumption and demand constitutes a critical process for manufacturing enterprises, supporting the effective management of energy resources and the strategic planning of operational activities. The annual energy consumption forecast, illustrated through a monthly breakdown over a twelve-month period, enables a detailed examination of consumption trends and seasonal variations. The chart incorporates four primary indicators: energy generated by the photovoltaic installation, energy consumed by the company’s equipment, energy drawn from the electric grid, and surplus energy returned to the grid. The summer months are particularly notable for the highest utilization of the photovoltaic system, attributed to the favorable climatic conditions prevalent in Poland, where increased solar irradiance enhances the efficiency of photovoltaic energy production. This elevated generation during the summer allows for a greater proportion of the company’s energy needs to be met through self-generated electricity. Accurate forecasting of energy consumption and demand based on these patterns enables enterprises to prepare for seasonal fluctuations, optimize investments in energy infrastructure, and improve cost management and energy efficiency throughout the year. The results of the forecasting analysis are presented in Figure 9.

Seasonal variation in solar energy generation and electricity demand, as evident from Figure 9, has significant implications for the economic and environmental effectiveness of a photovoltaic (PV) system. During summer months, with the peak sun irradiance, the PV system generates excess electricity that will more than meet the company’s direct energy needs. The surplus is returned to the grid with the possibility of monetary return in the form of net metering or feed-in tariffs, increasing return on investment. During winter, when the sun is weaker and energy consumption is greater due to lighting and heat load, there will be less system output. A greater proportion of electricity has to be taken off the grid, decreasing the potential for cost savings during these months. The aggregate system performance remains profitable, nonetheless, because the summer peak generation completely counteracts the production and demand seasonal imbalances.

Environmentally, these seasonal trends also impact the amount of carbon emissions displaced by the PV installation. During warmer months when there is maximum solar input and minimum grid dependence, there is maximum environmental gain as most of the clean energy is consumed immediately and less fossil fuel is used to cater to the energy requirements of the company. During months of low solar input in winter, there is reduced environmental gain as there is increased use of traditional sources of energy. Although this does fluctuate, the cumulative annual effect is impressively positive: with 10,366 kg of CO₂ emissions saved annually, the system is a cornerstone of the success of the company’s sustainability initiative. Important also is the fact that an understanding of—and capacity to predict—such seasonal variation also allows forward planning—such as the eventual incorporation of battery storage power stations—in an attempt to continually optimize both fiscal return and environmental effect in the long run.

Following the forecasting of energy consumption, the subsequent stage involves the analysis of solar energy utilization within the investigated company. Figure 10 provides a detailed monthly breakdown of solar energy use throughout the year. The chart presents three principal parameters: the total energy produced by the photovoltaic installation, the portion utilized for self-consumption, and the amount of surplus energy fed back into the electric grid. This representation facilitates precise monitoring and evaluation of the share of generated solar energy that is directly consumed versus that which is exported to the grid. Such an analysis is essential for assessing the operational efficiency and economic viability of the photovoltaic system, supporting the identification of potential areas for optimization and informing strategic energy management decisions.

The subsequent significant phase involves the examination of the photovoltaic installation’s economic performance parameters.

Table 7. Profitability parameters. Source: developed by authors.

ID	Profitability Parameters
1	Return on total expenditure	28,64%
2	Cumulative cashflow	EUR 128,162.26
3	Depreciation period	3.6 Years
4	Electricity generation costs	0.04 EUR/kWh

delineates key financial indicators, thereby facilitating an evaluation of the investment’s profitability in solar energy. A total expenditure return of 28.64% serves as a pivotal indicator of long-term financial gain. Moreover, a cumulative cash flow of EUR 128,162.25 underscores the robust financial efficiency of the project, while a payback period of 3.6 years highlights the timeframe within which the investment is expected to become profitable. Additionally, an electricity production cost of 0.04 EUR/kWh offers a basis for comparing production expenses with alternative energy sources, thereby assessing the competitive advantage of the photovoltaic installation in the market. Collectively, these profitability metrics are indispensable for a comprehensive evaluation of solar energy investments and for guiding strategic decisions related to the company’s development.

Figure 11 presents a simulation of the evolution of energy costs over a 26-year period, comparing scenarios before and after the implementation of the photovoltaic system. The results clearly demonstrate that, following the installation, the manufacturing company can achieve a substantial reduction in electricity expenditures throughout the analyzed timeframe. This serves as a critical reference point highlighting the advantages of adopting renewable energy technologies and may significantly influence investment decision-making processes. The long-term analysis of energy costs, both prior to and following the deployment of the photovoltaic system, provides a comprehensive insight into the economic benefits of green technologies and their role in enhancing the financial stability of the enterprise.

Table 8. Cash flow forecast (data expressed in EURO). Source: developed by authors.

	Year 1	Year 2	Year 3	Year 4	Year 5
Investments	−22,698.83	0.00	0.00	0.00	0.00
Power remuneration	6050.45	6052.21	5992.29	5932.96	5874.22
Saving on energy purchases	331.75	349.44	352.90	356.39	359.92
Annual cashflow	−16,316.63	6401.65	6345.19	6289.35	6234.14
Cumulative cashflow	−16,316.63	−9914.98	−3569.79	2719.56	8953.70
	Year 6	Year 7	Year 8	Year 9	Year 10
Investments	0.00	0.00	0.00	0.00	0.00
Power remuneration	5816.06	5758.47	5701.46	5645.01	5589.12
Saving on energy purchases	363.48	367.08	370.72	374.39	378.09
Annual cashflow	6179.54	6125.56	6072.18	6019.40	5967.21
Cumulative cashflow	15,133.24	21,258.80	27,330.98	33,350.37	39,317.59
	Year 11	Year 12	Year 13	Year 14	Year 15
Investments	0.00	0.00	0.00	0.00	0.00
Power remuneration	5533.78	5478.99	5424.74	5371.03	5317.85
Saving on energy purchases	381.84	385.62	389.44	393.29	397.19
Annual cashflow	5915.62	5864.61	5814.18	5764.33	5715.04
Cumulative cashflow	45,233.21	51,097.81	56,912.00	62,676.32	68,391.36
	Year 16	Year 17	Year 18	Year 19	Year 20
Investments	0.00	0.00	0.00	0.00	0.00
Power remuneration	5265.20	5213.07	5161.46	5110.35	5059.76
Saving on energy purchases	401.12	405.09	409.10	413.15	417.24
Annual cashflow	5666.32	5618.16	5570.56	5523.51	5477.00
Cumulative cashflow	74,057.68	79,675.84	85,246.40	90,769.91	96,246.91
	Year 21	Year 22	Year 23	Year 24	Year 25
Investments	0.00	0.00	0.00	0.00	0.00
Power remuneration	5009.66	4960.06	4910.95	4862.33	4814.19
Saving on energy purchases	421.37	425.55	429.76	434.01	438.31
Annual cashflow	5431.03	5385.60	5340.71	5296.34	5252.49
Cumulative cashflow	101,677.94	107,063.54	112,404.25	117,700.59	122,953.08
	Year 26
Investments	0.00
Power remuneration	4766.52
Saving on energy purchases	442.65
Annual cashflow	5209.17
Cumulative cashflow	128,162.26

provides a cash flow forecast over a period of 26 years, offering a comprehensive financial overview associated with the investment in the photovoltaic system. The table presents key elements such as the investment cost in the first year, savings on energy purchases for each year, annual cash flow, and cumulative cash flow. These details allow for an assessment of the project’s profitability and determination of its long-term impact on the company’s finances. Additionally, degradation and price escalation indicators are applied monthly throughout the entire considered time frame. According to the data presented in Table 8, this begins in the first year itself. Figure 12 illustrates the cumulative cash flow over the analyzed period.

In the long-term financial estimates presented in Table 8, key assumptions have been made on the PV system’s degradation and electric price inflation, both having significant impacts on the cash flows estimated for 26 years. The rate of degradation is the reduction of the power output of the PV panels by exposure to weather and aging. This computation assumes a realistic and conservative annual rate of degradation, which leads to the production of progressively less energy each year. Hence, while the system will be extremely efficient during the initial years, the level of electricity it generates—and the revenue earned as a consequence of energy savings and grid feeding—falls gradually with each passing year. This assumption maintains the financial model within the realm of reality for PV system performance and avoids overestimation of the system’s value.

For electricity price drivers causing increases, reproducing increasing market prices for the full 26-year duration, simultaneous introduction has been applied. These are founded on historical trends and give projections of an additional increase in the price of electricity due to inflation, shifts in energy policy, and uncertainty in fossil fuel markets. As the price increases, the value of the generated energy from the PV system also increases, generating more cost savings and cash flows throughout the year but reducing the efficiency of the system. The net consequence of these two opposing drivers of diminishing diminution and increasing price inflation is a financial situation of very fast cost replenishment in the first phase (within 3.6 years) and profitability in the long term happening well, to generate cash flow in total amounting to more than EUR 128,000 in year 26. Such assumptions thus corroborate reasonable, balanced estimates of the monetary viability of the PV system.

Table 8 presents the cash flow forecast of the PV installation over 26 years, including investment costs, remuneration of energy, savings due to energy purchases, annual cash flows, and the cumulative cash flow. This table provides a critical view on the financial viability of the PV system, showing returns that are foreseen from energy production and savings on consumption in the long-term perspective.

The investment in the first year is EUR 22,698.83; quite a high amount to be borne initially by the company for the installation of the PV system. This investment comprises the major expenditure in the forecast, because no further investments have been considered for the rest of the years of the forecast, which runs from years 2 through 26. This indicates that the installation is a one-time capital investment, while other costs thereafter are operation-related, such as maintenance and monitoring, which have not been included in the table. The initial capital investment is needed to set up the renewable energy installation but is defrayed by the long-term financial benefits accrued from energy production and savings. In the first year, the company has an annual cash flow of EUR 16,316.63. This initial loss is expected for any energy project with huge upfront investment, while its system starts operating and yielding returns gradually. However, the subsequent years reveal a gradual improvement in cash flows, as the company realizes positive cash flow from year 2 onwards to every subsequent year. Its cash flow grows each consecutive year, peaking in year 5 at EUR 6234.14. To expound on this, both revenues from power remunerations and savings on purchases of energy grow moderately every consecutive year.

The power remuneration line reflects that the company receives a steady income against the energy produced by the PV system, while the payments decrease by a small amount each year. These probably reflect the terms of the purchase agreement with the energy provider whereby the price of renewable energy could be decreased either as the system ages or as energy market conditions change. Despite this, the slight decline in power remuneration represents a steady revenue stream to the company and, thus, the overall financial sustainability of the system.

In parallel, savings from energy purchase increase every year, starting with EUR 331.75 in year 1 and growing gradually to EUR 442.65 in year 26. This is because the PV system works out for more efficiency and self-consumption in this growth. The company is relying more on the energy that it produces itself and less on the grid, and it therefore pays for fewer electrons. Savings grow more and more with each successive month for the financial standing of the firm while proving in general that a solution based on renewable sources is by far more cost-effective in the long run.

In the 5th year, the cumulated cash flow will be positive and amount to EUR 8953.70. That means the investment is already earned back and the system is presently producing net cash inflows. From this year onwards, the company will continue to profit from the PV system with substantial growth in cumulative cash flow each year. In this case, at year 10, the value of cumulative cash flow is at EUR 39,317.59, and at year 25, it reaches a value of EUR 122,953.08. The calculated cumulated values will indicate a measure of the profitability of the PV installation in the long run, considering increasing returns throughout its lifespan.

The annual cash stabilizes in a long-run perspective from year 21 in a range of EUR 5200 to EUR 5500 per year. Hence, after the initial years of the given project, one can state with a high degree of certainty that the financial benefit of a PV system will remain essentially constant, considering normal performances from renewable systems once the payback period has expired. Predictability of cash flow is good for financial planning and provides the company with a regular source of income or savings.

Cash flow keeps on cumulatively increasing, showing that, with time, the investment by the company keeps yielding a very substantial financial return. During year 26, the accumulated cash flow reaches EUR 128,162.26, showing that with time substantial financial benefits were reaped by the company from the initial investment in the system. This would mean that the PV system is durable and profitable, hence giving the company a strong return during its lifetime.

No further investment beyond year 1 would suggest that the PV system has been well designed and built to last, without significant capital expenditure beyond. Cost savings from reduced energy purchases and remuneration from the grid cost savings due to reduced energy purchases and remunerations from the grid add to a strong and growing positive cash flow, reinforcing the economic appeal of renewable energy investments.

In conclusion, the financial analysis of the photovoltaic system investment indicates favorable prospects for long-term profitability and cost savings for the examined Polish manufacturing company operating within the construction sector. Table 8 presents a 26-year cash flow forecast, while Figure 12 depicts the cumulative cash flow over the same period, illustrating the progressive accumulation of profits resulting from the adoption of solar energy technologies. These financial data provide a comprehensive basis for understanding the economic advantages associated with the implementation of the photovoltaic system and serves as a critical foundation for informed strategic decision-making.

6. Discussion

6.1. Overview of Key Findings

Such findings testify to the importance of renewable energy, mainly photovoltaic systems, in the enhancement of energy efficiency and sustainability of construction sector enterprises. In this way, alternative energy sources, like solar energy, have greatly contributed to reducing energy costs and carbon dioxide emissions, as can be seen by the case of the Polish manufacturing company that reduced its annual CO₂ emissions by more than 10,000 kg. These findings follow the global trends where renewable energy is increasingly embraced not only as a mitigation approach to environmental impacts but also as an energy security measure. Economically, too, the integration of photovoltaic systems is very promising. In fact, the low energy cost generated by solar installations, together with a relatively short payback period of 3.6 years, is a very good argument for the construction industry. The large accumulated savings after 26 years, over one hundred thousand euros, certainly prove that the solutions of renewable energy are long-term cost-effective. This might be a reason to believe that operation costs, with appropriate on-site integration of solar energy, are likely to decrease, besides offering companies a stable and reliable source of energy, isolating them from the volatility of conventional energy prices.

Much better integration of renewables is allowed by enhanced EMSs and energy storage technology. In turn, construction companies are able to monitor in real time the consumption of energy, thereby controlling and adjusting it to make full use of on-site energy generation, minimize waste, and ensure it is used as effectively as possible. These technologies create a synergistic effect when combined with photovoltaic systems, enhancing operational efficiency and stabilizing energy supply, especially during peak demand periods or grid outages.

Of these, perhaps the most important conclusion derived is that such renewable energies will be instrumental in bringing far-reaching changes to the building construction sector, such as lessening the reliance on fossil fuel-based systems and reducing each firm’s ecological footprint, thereby contributing to growing global initiatives to switch towards alternative fuels and energies. It finds its ideal example in the integration of photovoltaic systems, whereby technologies relating to energy-efficient lighting and HVAC systems can also be integrated to further enhance the concept of energy efficiency. The need is therefore holistic in energy management strategies towards attainment of sustainability objectives in their importance to both governments and consumers.

This paper brings to the fore the financial and environmental benefits of photovoltaic systems. On the other hand, the successful integration of renewable solutions depends on many factors, such as technological advancement, policy support, and the willingness of an enterprise to invest in a system. As expensive as it may be for some companies to afford the initial installation, the long-term savings thereby outweigh the challenges. As the building and construction industry develops and is expanding further, this general trend towards renewable systems probably stands at the core of further development in the area.

6.2. Operational and Technological Implications

The energy consumption pattern of the company is highly seasonal, peaking in winter months such as January and December. This is due to a variety of factors common in colder climes, especially in countries like Poland, where winter months receive shorter daylight hours and lower temperatures. During these months, demand for heating and lighting is notably higher. The cold weather demands heating, and buildings need to be fitted with energy-intensive systems in order to maintain comfortable indoor temperatures. The longer nights also mean longer use of artificial lighting, adding to the energy demand.

In addition, during winter, several weather conditions usually produce a decrease in the efficiency of photovoltaic systems, especially in low-irradiance conditions [36,37]. The reduced sunlight hours, together with probable snow cover or overcast skies, result in lower energy output from the photovoltaic panels and thus generate a mismatch between energy demand and production. This means that even though the company requires more energy to meet its needs during winter, the PV system’s capabilities actually decline, thus compelling an increased dependence on external sources of energy. It follows that this seasonal discrepancy forms one of the critical considerations in the optimization of integrated PV systems, since their performance becomes a deciding factor to include complementary strategies for energy storage or systems that can balance out any demand–supply gap at times of low irradiance. The general lifecycle impact of the PV panels involves production, transport, installation, and waste management issues that are relevant in the overall environmental benefit evaluation of the solar energy systems, especially for low-irradiance climates such as Poland. In this type of climate—with much lower sun intensity and shorter sunlight exposure in comparison with other places in the world—the study of the efficiency of PV systems in compensating for their environmental impact during their operational life becomes relevant [72,78].

The production phase is probably the most energy-intensive phase of the life cycle of these PV panels. The making of photovoltaic cells utilizes raw materials such as silicon, glass, and various metals; the extraction and processing of these materials can result in considerable environmental impacts. For example, silicon has to be mined, refined, and purified—all energy-intensive activities that are often powered by fossil fuels, thus contributing to greenhouse gas emissions. Then, making the photovoltaic panels themselves is energy-intensive, and a lot of this energy consumption occurs in parts of the world where electricity is still primarily provided by non-renewable sources, further contributing to a high carbon footprint of the panels [79,80].

Post-production, the transport of these photovoltaic panels from the various production plants to installation points uses resources from the environment. It typically needs to cover long distances where ground transportation may be required, supplemented with shipping that generally involves conventional fossil fuel vehicles or vessels; this consumes a large quantity of energy, with the resultant emissions constituting another environmental cost against the system [81]. Transportation can be particularly relevant in low-irradiance regions where the environmental benefits of generating solar power are reduced; this reduces the net positive impact of the energy system. Installation of PV panels involves lower energy and material use compared to production or transportation [82]. That translates into more significant physical installation of panels on rooftops or ground-mounted arrays, more equipment, and labor, which together raise the environmental footprint. This includes mounting systems, wiring, and sometimes even batteries for energy storage; things that demand resources which may be contributory to the environmental cost. Nonetheless, the direct emissions in the installation phase are relatively low as compared to the other phases [83].

The disposal phase becomes particularly important at the end of the operational life of the PV system. The normal operational life of a photovoltaic panel is about 25 to 30 years, and at the end of this period, it needs to be disposed of or recycled properly to avoid environmental hazards. Presently, recycling infrastructure for PV panels is at a developing stage and most of the panels end up in landfills. This raises concern over possible environmental contamination by hazardous materials, probably present in some types of panels, such as cadmium or lead. With the growth in the solar industry, the need for effective and sustainable disposal methods becomes increasingly urgent, especially with the increasing volume of panels reaching the end of their operational lives [79,80].

6.3. Linking This Study’s Findings to the Research Questions

In low-irradiance climates, the environmental benefits due to PV panels are more uncertain as energy output is seriously reduced. Solar energy systems generally tend to have a relatively lower carbon footprint over their lifetime than fossil fuel-based electricity production; in regions with low solar radiation, however, the panels take longer time to recover the energy which has been invested in producing, transporting, and mounting them. This extended payback period therefore implies that the associated environmental dividends—in particular, the reduction in CO₂ emissions—are slower to accrue, which makes the effectiveness of solar energy systems in such regions more difficult to justify on solely environmental grounds [81,82,83].

In spite of these considerations, it has to be recalled that even in low-irradiance cli-mates, PV panels contribute to a reduction in the reliance on fossil fuels, which remains their principal environmental advantage. Taking it to a lifecycle basis, usually over the long term, the energy savings from the generation of clean solar power would, even if the payback is longer, offset the environmental impact of the panels. However, with a view to maximizing the environmental benefit from the installation of PV systems in low-irradiance regions, energy efficiency in manufacture should be underlined, along with improvements in recycling techniques and reducing transportation emissions through using materials sourced locally and manufacturing locally wherever possible.

The lifecycle impact analysis done for PV panels installed in low-irradiance climates suggests that although the immediate environmental returns may not be quite as high as for those in sunnier regions, in the long term, PV technology still offers a significant long-term benefit in terms of reducing dependency on carbon-intensive energy sources. The key to optimizing the environmental impact of PV systems lies in addressing challenges with production efficiency, transportation emissions, installation methods, and the future disposal of panels. As technology and infrastructure continue to evolve, the environmental effectiveness of solar energy—even in regions of low solar irradiance—will continue to improve in support of the wider global effort to reduce carbon emissions and mitigate climate change.

In striving for a sustainable and environmentally friendly future, several critical points emerge from the discussion of energy and environmental challenges:

• Human activities have significantly increased greenhouse gas concentrations in the atmosphere, leading to rising global temperatures, elevated sea levels, and more frequent natural disasters. These effects are causing widespread health issues and impacting ecosystems and economies.
• The shift from fossil fuels to renewable energy sources is crucial for mitigating environmental impacts. Technological advancements in energy generation and storage are key to this transition, which aims to address both climate change and resource shortages.
• Renewable energy is central to the global energy transition, offering potential for economic and industrial growth. However, this transition is influenced by social changes and rising production costs, which must be managed to ensure its success.
• Effective political will and leadership are essential in advancing renewable energy adoption. Both developed and developing countries play critical roles in investing in and supporting renewable energy technologies.
• The construction sector is a major contributor to global energy consumption and CO₂ emissions. Increasing energy efficiency and integrating renewable energy can significantly reduce these impacts. Examples of successful implementations include energy-efficient buildings and renewable energy technologies.
• The comprehensive studies conducted on the selected example underscore the importance of assessing the financial viability of installing photovoltaic panels.
• EMSs and energy storage technologies are vital for optimizing energy use and stabilizing supply. These innovations help improve operational efficiency and support the broader integration of renewable energy sources.
• Implementing renewable energy solutions not only reduces operational costs and CO₂ emissions but also supports sustainable development. The long-term economic and environmental benefits are significant, making a strong case for continued investment in these technologies.

Most would still view the relationship between nuclear and renewable energy development as complementary, not competitive. Each source of energy has an important contribution to make in helping to address global challenges related to reducing greenhouse gas emissions and a sustainable energy future. Nuclear power can steadily supply large-scale electricity, base-load electricity, with no direct carbon emissions, thus complementing such intermittent renewable energy sources as solar and wind [84]. Though the plants are able to produce steady electricity, renewables are on higher ground where sustainability over longer periods is concerned, inasmuch as they are independent of any finite resources. Therefore, a balanced mix of nuclear and renewables would create the desired stability, resilience, and low-carbon energy system [85].

While renewable energy is sure to play a fundamental role in de-carbonization in the energy sector, there are a number of disadvantages. First and most crucially, it is intermittent; that is, solar and wind resources vary with weather conditions and also throughout the day. Hence, it is unreliable without extensive energy storage solutions. This variability calls for the application of complementary technologies, including energy storage systems or grid management approaches, which will ensure a reliable supply of electricity. Further, the initial installation costs associated with renewable energy systems—solar panels and wind turbines—can be quite high; though they save money over a long period, the initial cost keeps many businesses and people away [84,85,86]. Other factors make certain renewable technologies not scalable, considering particular geography and climate conditions; not every region might have the vast deserts or wide-open plains with minimal population that are appropriate for large solar or wind farms. The fact that wind turbines and solar panels entail huge space and material requirements also means that most renewable energy technologies induce environmental concerns both at the fabrication and land-use stages, further complicating their widespread deployment [87,88,89].

Among those which have a bearing on the result of the current study is the Theory of Technological Innovation and Diffusion, which holds that technologies of new adoption—like photovoltaic systems—diffuse according to a predictable pattern in such a way that adoption occurs early among a very limited set and gradually spreads among large segments as the technology ripens up with economic viability [90,91,92]. Indeed, the following fact corroborates this suggestion, because such integration of photovoltaic systems into construction enterprises contributes to cost reduction and environmental benefits; simultaneously, it can be regarded as a kind of indicator of the fact that renewable energy technologies have a chance to diffuse into other sectors. The relatively short payback period in this case study, 3.6 years, suggests where such technologies become accessible to a wider range of companies, which would in turn indicate that critical mass among adopters is necessary if broader societal and economic benefits are to be achieved. Furthermore, the rapid rate of diffusion in the adoption of EMSs and energy storage technologies supports such findings, since their adoption is diffused with complementary innovations, again underlining the concept of co-evolution of technological systems in order to provide an efficient solution [93,94,95].

In this respect, energy management systems and energy storage systems have financial, operational, and environmental benefits that must be viewed in their entirety. These systems will optimize energy utilization and reduce costs while enhancing operational resiliency, contributing to environmental sustainability with minimal carbon emissions and furthering greater energy independence. The case presented in this paper represents the great potentiality of EMSs and storage systems, crucial in raising the effectiveness of photovoltaic systems, especially in low-irradiance climates. In the near future, these technologies are bound to be embraced, considering their long operational success and contribution towards shifting to renewable energy.

The EKC hypothesis postulates that up to a threshold point, economic growth is related to increased deterioration in environmental quality, but beyond which further growth in the economy tends to improve environmental quality, with a shift in technology and policy [96,97,98,99]. The results of this analysis give credence to this hypothesis within the context of the construction industry. Generally speaking, energy consumption and carbon emissions go up with the growth of heavy industries like construction, but the application of renewable energy technologies—for example, a photovoltaic system—develops toward sustainable practice that enables a state to reduce environmental impact with little influence on economic growth. It proves that the construction industry can achieve both economic and environmental goals, even being so energy-intensive, as soon as renewable energy solutions are applied, hence confirming the EKC hypothesis of economic development, ultimately leading to lower emissions under appropriate technologies and policies [100,101].

The energy transition and decarbonization theory gives an overview of the shift that has taken place from fossil fuels to renewable sources of energy [102,103,104,105]. This theory places a strong emphasis on the fact that societies and industries can only be made low-carbon by a gradual transition into cleaner, low-carbon energy systems [106,107,108,109,110,111,112,113,114]. This study thus established empirical evidence in the construction sector for this theory. Such applications of photovoltaic systems contribute directly to the decarbonization of energy use in the sector, decrease dependence on fossil fuels, and reduce GHG emissions. The integration of renewable energy systems and complementary technologies in storage and the like, or EMSs, represents a much wider trend toward energy system transformation [115,116,117]. This energy transition is not only urgently needed for environmental reasons but also to enhance energy security and operational stability, as has been proved by the ability of construction companies to keep working during peak demand periods or grid outages. Results highlight that energy transition and decarbonization are actually interconnected processes which, for their success, need technological innovation, investment, and enabling policy frameworks.

Mass application of the findings of this study to large-scale construction companies is a complex process that takes into account economies of scale, greater energy requirements, and more complicated organizational levels. Large companies have activities distributed over more than one facility and use much more energy than small and medium-sized enterprises. Consequently, the integration of photovoltaic (PV) systems in such applications could potentially realize proportionally greater economic rewards as well as environmental advantages. With more roof or ground area, large companies are able to support large-capacity PV systems and therefore reap larger levels of energy autonomy and even generate significant amounts of excess energy to sell to the grid or redistribute. Apart from these factors, these businesses can also afford to invest in associated technologies such as large-capacity energy storage plants and advanced energy management systems (EMSs), enhancing energy use even more and stabilizing production in operations. Batch purchasing economies of scale, maintenance internalized to the business itself, and high-end energy modeling software also make renewable energy initiatives cost-effective in the long term for big corporations.

In applying the findings to other regions, some contextual factors have to be considered, such as climatic conditions, energy market forces, and policy. Regions that are more exposed to higher levels of solar irradiance—i.e., southern Europe, North American areas, or Asian and African emerging economies—will benefit even more from adopting PV systems through increased yields in the form of annual energy output. There, the system’s efficiency and efficiency ratio as a whole would be sure to outstrip that recorded in temperate climates like that of Poland. State incentives, regional energy prices, policy aid schemes, and feed-in prices will determine payback periods as well as economic viability of the kind to a large extent, however. In addition, where there is poor grid stability or energy volatility, renewable systems augmented with storage facilities can offer a strategic hedge against operating risk. Thus, while the underlying technical approach and assumptions of this present study are replicable, their successful replication entails localization to specific environmental, regulatory, and economic conditions.

The results of this study reaffirm and build on the contributions of previous scholars in exploring the applicability of photovoltaic systems to industrial- and construction-related purposes from an environmental perspective. In agreement with Oteng et al. [70], monocrystalline and multicrystalline PV modules are able to mitigate the global warming potential considerably if applied under ordered energy policies. Similarly, Tsang et al. [69] established the potential of organic PV technology to outperform traditional silicon modules in carbon payback. The 10,366 kg CO₂ savings per annum by the Polish building company under consideration here concurs with this evidence, showing that even traditional PV systems, when well optimized and maintained, yield measurable benefits in environmental sustainability. This matching of simulation outcomes with empirical data gives added weight to the argument that the construction sector, especially for Central European climates, can still gain much in terms of sustainability by utilizing solar power.

Economically, the findings of this study are supplementing previous studies by researchers who have shown the cost-effectiveness of solar power in energy-based industries. References [35,36,37,38] all quote direct cost savings in electricity and long-term profitability as significant advantages of PV deployment. The model used here—a 3.6-year payback time and a cumulative financial return in excess of EUR 128,000—gives strong empirical evidence to underpin such arguments. While most reference studies employ model-based estimation or firm-level averages, this project holds actual, geographically-specific data from a singular firm within the construction sector’s manufacturing industry segment in Poland. It reflects that small-scale investment translates into output, as documented in broader economic studies, and suggests solar-energy-based technologies are economically feasible independent of large-scale multilateral schemes.

Through the integrative process outlined in references [36,37,38,39,40,41], the present work posits the synergic advantage of combining PV systems with sophisticated energy management systems (EMSs). Despite the case subject not boasting a storage battery unit, the attendant self-consumption level (30.5%) and residual energy exported to the grid reveal a situation optimally described by authors who attribute necessity to energy optimization technologies. The authors are keen to point out that EMSs can be utilized to maximize the efficiency of renewable systems via supply–demand mismatch minimization. The simulation run here—replicating problems in the literature concerning temporal imbalances in solar generation—confirms that operational efficiency is restrained without storage or consumption shifting. This confirms calls in the literature considered for review for combined energy systems that include PV, EMSs, and potentially energy storage, as the answer to tapping the optimum operational and economic potential of renewable energy in construction.

• RQ 1: To what extent can the integration of renewable energy reduce carbon dioxide emissions?

The findings of this study directly respond to Research Question 1 (RQ1). The simulation results show that the installed photovoltaic (PV) system has the potential to save approximately 10,366 kg of CO₂ emissions annually. This quantifiable environmental benefit attests to the fact that the use of solar energy in the energy infrastructure of construction manufacturing firms can be an excellent source of de-carbonization efforts. The findings corroborate more far-reaching sustainability goals at the national and EU levels, i.e., that PV installations are not only an economic investment but also a strategic environmental project. The results are also in line with international climate goals, according to which it can be assumed that decentralized renewable energy systems are key compounds of the ecological revolution of the construction industry.

• RQ 2: How does the adoption of photovoltaic systems impact electricity cost reduction in the construction industry?

In the instance of Research Question 2 (RQ2), this research obtains significant cost savings through the minimized use of electricity supplied by the grid. For the period of 26 years, the net cash flow is estimated to be more than EUR 128,000 and the cost of electricity generation with the PV system is estimated at as low as 0.04 EUR/kWh. These estimates indicate the economic viability of investment in the use of renewable energy. More generally, the 3.6-year payback period specifically shows that not only is there a return on investment but that it is quite immediate. This conclusion dispels literature alarms about high initial cost of solar installation by showing that the long-term savings overwhelm the expenses.

• RQ 3: What are the financial implications of integrating solar energy into manufacturing processes in the construction sector?
• RQ 4: To what extent does the implementation of renewable energy systems improve the energy efficiency of enterprises in the construction sector?

For Research Questions 3 and 4 (RQ3 and RQ4)—the economic benefits and energy efficiency improvements due to the installation of renewable energy—this study has concrete empirical answers. The studied PV system provided 31.8% of the firm’s total energy requirement, with excellent energy independence and operating efficiency improvements. The solar power permitted self-consumption of 30.5% of the energy, while the rest was injected into the grid, therefore enabling partial economic compensation through feed-in systems. Although there was lower total self-consumption through the absence of an energy storage system, the results still strongly indicate improved energy efficiency and economic performance because of the addition of renewable energy. Accordingly, this study confirms that solar integration not only offers environmental benefits but also reshapes business dynamics, reducing exposure to market uncertainties and strengthening long-term financial security.

6.4. The Limitations of This Study

The limitations of this study mostly pertain to the scope and generalization of the findings. The case study was grounded in a Polish manufacturing company in the construction sector, and as such it may not be fully representative of a broader diversity of companies in different geographic locations or those operating in other sectors. Moreover, it may also be biased by the particular environmental, economic, and regulatory conditions of Poland; thus, a repetition of similar results may not be an easy task for other countries under different energy markets, government policies, or climates. Finally, this paper mostly covers photovoltaic systems, not reviewing the rest of the renewable sources or even alternative energy technologies that complement them or provide more effective solutions in certain contexts. Other future research could be directed at the long-term implications of integrating renewable energy systems into the construction industry, in particular regarding how such systems will evolve as energy storage technologies advance, energy management systems, and integration with other renewable sources such as wind or biomass.

7. Conclusions

The conducted research emphasizes the urgent need to address climate change and resource scarcity through the immediate transition to renewable energy and its more efficient use. The construction sector will play a vital role in this shift, offering substantial opportunities to reduce carbon footprints and decrease dependence on fossil fuels, particularly through the integration of solar energy technologies. Despite the high upfront costs and current limitations of national grids to accommodate large volumes of renewable energy, photovoltaic (PV) technologies hold significant promise for the construction industry. Technological advancements such as increased solar panel efficiency, cost reductions, and improved energy storage systems are making solar energy increasingly accessible and viable. The application of advanced algorithms and artificial intelligence in energy management systems (EMSs) further enhances energy efficiency by optimizing energy consumption and reducing greenhouse gas emissions. When combined with energy storage solutions, these systems not only stabilize energy supply but also support the broader shift toward energy independence and sustainability. Leading construction companies such as Saint-Gobain, Skanska, and LafargeHolcim are already demonstrating how the incremental integration of solar power and EMSs can lower operational costs, reduce emissions, and contribute to long-term environmental sustainability. Their initiatives serve as benchmarks for the broader sector.

The case study conducted on a Polish construction manufacturing company clearly shows that PV systems deliver considerable environmental and economic benefits. The installation covered 31.8% of the company’s annual energy demand, reduced CO₂ emissions by 10,366 kg per year, and yielded a strong return on investment with a short payback period of 3.6 years. By lowering electricity consumption from the grid, PV systems generate substantial long-term savings. Financial incentives such as government subsidies and tax reductions further enhance the attractiveness and financial feasibility of adopting solar energy solutions. Additionally, solar integration offers direct economic benefits by offsetting daytime energy use and, in some cases, generating income from surplus energy sold back to the grid. Combining a PV system with an EMS maximizes energy efficiency by reducing transmission losses and aligning consumption more closely with generation. This not only ensures operational continuity during grid outages or peak demand but also strengthens overall business resilience. Importantly, the environmental impact of solar adoption is undeniable. The reduction in CO₂ emissions, as evidenced by the case study, aligns with global efforts to mitigate climate change. As renewable technologies become more widespread, their contribution to emissions reduction will be even more significant. With electricity generated from solar power becoming increasingly cost-competitive compared to conventional sources, the economic case for investment is strong. A short payback period, followed by decades of savings, makes PV systems a highly beneficial solution for the construction industry.

In summary, the integration of renewable energy, particularly photovoltaic systems, into industrial operations represents a strategic pathway to achieving sustainable business growth and economic resilience. It supports environmental goals, enhances energy independence, and offers long-term financial benefits, positioning the construction sector as a key player in the global sustainability transition.

The scientific value of this paper is that here, a full attempt was made to consider the influence of renewable systems, and among them, especially photovoltaic ones, on the construction industry. It gives a good outlook of how such systems may be of contribution to the lowering of carbon dioxide emissions, reduction of energy costs, and growth in general energy efficiency. This paper, therefore, indicates the economic and environmental benefits of integrating renewable energy into the construction industry and thus provides a data-driven case for the adoption of such technologies in this traditionally energy-intensive sector. It also discusses financial implications of renewable energy integration, giving a long-term perspective on cost savings, return on investment, and the role of complementary technologies like energy management systems (EMSs) and energy storage solutions. Therefore, this paper contributes to the growing body of research works supporting the transition to sustainable energy practices by filling the knowledge gap between renewable energy diffusion and operational efficiency in the construction industry. These findings are useful in making informed policy decisions, industry practices, and further research in renewable energy applications within a larger context of industrial decarbonization and sustainability.

Future research could also use multiple case studies from different regions, industries, or firm sizes to get a wider feel for the factors likely to influence the successful adoption of renewable energy.