Life Cycle Analysis of a Photovoltaic Power Plant Using the CED Method

Abstract

There is a significant demand for materials and energy throughout the manufacturing and construction of a solar power plant’s component parts. Electricity and fossil fuels are used in enormous quantities during the industrial processes in the photovoltaic power plant’s life cycle. It is then necessary to assess the energy needs, especially during production processes, to improve the efficiency of energy usage and management of natural resources from the global perspective. This will lead to a decrease in natural resource consumption and electricity demand. The main aim of this study was to assess the energy demand in the life cycle of the photovoltaic power plant and identify the most energy-intensive stages and components of this type of installation throughout its life cycle. The study of energy consumption in the whole life cycle was conducted for a 2 MW photovoltaic power plant situated in the northern region of Poland using the Life Cycle Assessment (LCA) methodology, particularly the Cumulative Energy Demand (CED) method. Two post-consumer management scenarios were investigated: recycling and landfilling. It was found that the life cycle of PV panels and the inverter station had the largest energy demand among all the components. This study revealed that, compared to recycling, the life cycle involving post-consumer management in the form of landfilling had a higher total energy demand of 4.09 × 10⁷ MJ. The results of this investigation validate the benefits of recycling. Thus, recycling ought to be commonplace to improve the environment.

1. Introduction

1.1. Background

Poland and other nations around the world will require an increasing amount of energy each year (

Table 1. Energy consumption by source, World [3].

World	Years
Energy Consumption by Source [TWh]	1965	2022
Other renewables	55.95	2413.81
Biofuels	9.03	1199.21
Solar	0.00	3448.24
Wind	0.00	5487.60
Hydropower	2729.89	11,299.82
Nuclear	72.47	6702.34
Gas	6303.83	39,413.04
Coal	16,140.18	44,854.04
Oil	17,996.53	52,969.59

). Conventional methods of producing electricity degrade the environment. Energy must originate from sources that are more environmentally friendly and release fewer harmful elements into the atmosphere to combat climate change. Because of this, environmental efforts entail producing more so-called “green” or “cleaner” energy. Environmental protection objectives should be taken into account throughout the entire period of operation of technical facilities. It will be impossible to bring about beneficial changes in the quality of the environment if the current operating model—which is unreasonable from the perspective of sustainable development and consists of the production and sale of products, generating waste, and depositing it in the environment—is maintained. The goal is to shift the management model to one that is as close to a closed energy and matter cycle as possible through the development and implementation of initiatives targeted at the ecological, energy, and economic optimization of technological facilities. This shift will lessen the detrimental effects on the environment while increasing the efficiency of the use of raw materials [1,2].

The structure of power generation has changed from 2000 to 2022. In 2022, coal made up 69.2 percent of the energy produced in the Polish power grid. Fossil fuels made up 79.0 percent of the entire electricity mix. Poland’s share dropped by 19.4 percentage points (to 98.4%) between 2000 and 2022, yet it still ranked second in the EU in 2022. In 2023, 75 percent of energy came from fossil fuels. In the Polish electricity mix, 64.8% of it comes from coal alone. About a decade earlier, in 2013, the installed power of photovoltaic panels was not greater than 3.5 MW, about 4000 times less. However, current growth trends are strong; in 2021–2022, Poland’s solar-powered electricity production more than doubled, from 3.9 TWh to 8.2 TWh (+107%). After Kenya and Lithuania, this was the world’s third-largest growth. The overall growth in electricity generation from renewable energy sources in 2021–2022 was 23.5% (from 30.6 TWh to 37.7 TWh), or 21% blend. At the same time, Poland’s heat pump market is expanding rapidly. The European Heat Pump Association (EHPA) reported that 195,000 heat pump systems were sold in 2022 for heating purposes, representing the largest annual growth in Europe at 102%. (EHPA, 2023) (Figure 1). The number of pumps sold exceeded 203,000, with 188,000 of those being air/water types (central heating and domestic hot water), whose sales growth dynamics were the largest (90-fold increase in 2013–2022), according to PORT PC data (2023) [4].

These days, it is necessary to assess the life cycle of energy infrastructure. From the first phase of the cycle, which is the formulation of the requirement, to the last, which is post-consumer management, control over it should be exerted. The evaluation of current interactions—both beneficial and detrimental—between the technical facility and the environment is made possible by this approach. The fundamental tenets of sustainable development align with assessing an object’s relationship with its surroundings throughout its entire life cycle. The concept stage is where the Life Cycle Assessment (LCA) gets started. Not only are the requirements ascertained during the conceptual stage, but also the technologies and processes required to create the finished, operational technical facility. Therefore, gathering all the information required for design, production, operation, and post-use management is one of the primary objectives of object life cycle analyses [2,5,6,7].

1.2. Research Contribution

The global literature contains a few studies on the life cycle of solar power plants. Still, it is rare to find analyses using the LCA methodology in Poland. The article makes an effort to provide an overview of the regional viewpoint on the subject of the environmental impact of the chosen renewable energy source. This led to an examination of an already existing photovoltaic power plant. This power plant has 2 MW of power installed and is located in northern Poland. Thus, the primary goal of this work was to use the CED approach to assess the energy demand in the life cycle of the photovoltaic power plant and identify the most energy-intensive stages and components of this type of installation throughout its life cycle to formulate recommendations for further pro-ecological development of structural elements, operation processes, and life cycle management systems of these facilities.

2. Literature Review

The life cycle of solar power plants has not been extensively studied in the global literature. Still, there is a lack of popularity for LCA technique analyses in Poland. It was decided to perform an actual case study of a photovoltaic power plant. The power plant is located in northern Poland. This work aimed to define a local perspective on the environmental impact of a selected renewable energy source. The author aimed to raise public awareness of the environmental effects of the renewable energy source’s life cycle while highlighting more general issues by maintaining a local viewpoint. The majority of research only considers how the life cycle of a power plant affects GWP (Global Warming Potential), ignoring additional detrimental effects on human health, the environment, and the depletion of raw materials, all of which need in-depth examination, particularly from the standpoint of the sustainable development of energy systems.

The majority of LCA research focuses solely on solar panels or the materials used to make them. Studies that examine the photovoltaic power plant in its whole practically do not exist. For instance, the majority of evaluations were focused on silicon-based components: Alsema [1], Frankl and others [8], Fthenakis and Kim [9], Dones and Frischknecht [5], and Kato and others [10] studied a life cycle of single-crystalline silicon, sc-Si modules. On the other side, the analyses made by Alsema [7,8], Fthenakis and Alsema [8,11], Fthenakis and Kim [9,11], Dones and Frischknecht [9,12], Ito and others [12,13,14], Kato and others [14,15], Nomura and others [15,16], and Oliver and Jackson [16,17] were based on multi-crystalline silicon, mc-Si. Alsema [7,8], Ito and others [13,14], and Kato and others [17,18] studied amorphous-silicon, a-Si. Only the solar panels themselves are the subject of this research that is being presented. They don’t consider the photovoltaic power plant’s whole technical setup.

One can locate research on photovoltaic systems among the most recent studies. Research issues include greenhouse gas emissions [10,18], life cycle assessment (LCA) [10,19], the contrast between EIA techniques [19,20], and LCA of the wind farm power plant [20,21]. Other research is about, for example, the Environmental Impacts of Various Heating Systems Based on LCA [21,22] or the Capacity Optimal Allocation Methods [22,23].

There are accounts of the application of the CED technique for life cycle assessments in international literature: Berardi [24], Shukla and others [25], Huijbregts and others [26], Mahmud and others [27], Amor and others [28], and Mahmud [29]. The subject of photovoltaic power plants’ emission intensity has been covered by some writers: Gürzenich and Wag-ner [30], Dolgun and others [31], and Tariq [32].

There are no recent studies that address the solar power plant as a whole rather than just the individual panels in the literature.

Life cycle analyses often focus solely on individual solar panels, not the overall solar power plant. This process restricts the range of indicators that other photovoltaic power plant components can produce that negatively affect the environment. In our research, the full photovoltaic power plant—including the electrical setup, solar panels, supporting structure, and inverter station—is examined. These are a solar power plant’s four most crucial operational teams. As a result, this work’s breadth serves to highlight a wider issue.

The primary goals of this research are the advancement of science and knowledge enrichment, but they also include acquiring knowledge that is as exact, certain, and general as feasible, with the highest level of simplicity while also standing out for having the most information.

3. Materials and Methods

3.1. Object of Analysis

Poland’s northern region is home to the solar power facility under analysis. It generates 1900–2200 MWh per year on average (statistics provided by the investor based on 8 years of operation). Because weather patterns might change year to year, variations in the quantity of energy produced can range by an average of 10%. For this reason, the tested installation’s 2000 MWh annual production was simplified and used as the reference unit for additional analyses. About 300,000 kg is the total weight of the materials, components, and polymers in the tested photovoltaic power plant (

Table 2. Bill of materials for the solar power plant under analysis (investor data).

Bill of Materials
Material Name	Mass	Unit
Aluminum	85,120	kg
Steel	82,000	kg
Solar glass	79,230	kg
Copper	5000	kg
Others	9264	kg

and

Table 3. List of the solar power plant components that have been examined (investor data).

List of Elements
Name of the Element	Mass	Unit
Photovoltaic modules	161,100	kg
Supporting structure	53,320	kg
Inverter station	40,000	kg
Electrical installation	6194	kg

). The proportion of components and materials used in the photovoltaic power plant is shown in Figure 2 and Figure 3. Two supports are installed in the PV panel supporting structures (double, two-support system). The kind of soil (a reclaimed dump) on which they were constructed made this process necessary. The solar panels are positioned at a 40° angle facing south. To construct the power plant under analysis, 8334 (240 W) polycrystalline photovoltaic modules have to be installed. A model with a maximum efficiency of 17.7% was chosen. For the first ten years and the next fifteen, the manufacturer offers 91.2% and 80.7%, respectively, of the rated power. There are 60 cells in every single module (investor data).

3.2. Methodology

The main objective of the LCA (Life Cycle Assessment) technique is to evaluate the possibility of environmental hazards. By measuring the quantity of materials, energy, and waste released into the environment and evaluating the effects of processes on human health, the environment’s overall quality, and the depletion of raw materials, it is feasible to identify potential environmental impacts. Every phase of a specific product’s life cycle is covered by the analysis, beginning with the first step of life cycle assessment (LCA), which involves obtaining the raw materials needed for production and moving on to the manufacturing, distribution, and post-consumer management phases. This means that more effective management of matter and energy over their entire life cycle is made possible using the Life Cycle Assessment (LCA) method when designing technical facilities for renewable energy. This leads to a number of benefits, including reduced consumption for manufacturing and increased use in recycling processes [2,6,33,34,35,36,37,38].

The ISO 14000 standards defines the four essential components of the Life Cycle Assessment (LCA) framework as defining the purpose and scope, analyzing the set of inputs and outputs (Life Cycle Inventory, or LCIA), effect assessment (Life Cycle effect Assessment, or LCIA), and interpreting the findings [39]. In general, a Life Cycle Assessment (LCA) study entails identifying and quantifying potential environmental impacts associated with a product’s ability to fulfill a certain function. The reference stream, function, and functional unit are essential elements of the Life Cycle Assessment (LCA) methodology. An example of a functional unit in life cycle analysis research is the quantitative effect of a product system, such as the total energy generated in MWh by a solar plant over the course of its life cycle. Conversely, the reference stream is characterized as a measurement of the processes or outputs of a particular product system required to achieve the function represented by the functional unit [37,38,40,41]. A graphic representation of the key phases of an LCA analysis is shown in Figure 3.

The lifetime impact assessment phase’s main purpose is to provide the information required for assessing and analyzing the outcomes of the preceding phase. The following should be done to understand and evaluate the significance of the impact assessment on the environment surrounding the technical facility:

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(Possible) allocation and organization of data;

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Assigning and organizing data to the individual impacts considered;

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Analysis of the type and quantity of waste generated;

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Determining how to manage the generated waste;

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Data grouping;

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Classification of data according to the type of its impact;

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Characteristics of data classes;

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Organizing the results and prioritizing them according to their importance and level of impact on the environment.

The initial step in an LCA analysis is to ascertain the goal and parameters of this study. This is where the most crucial choices that affect the overall energy and ecological evaluation are made. The objective of the analysis that will be performed in this work is to evaluate the life cycle impacts on energy and the environment associated with a particular solar power plant (comparative analysis). The LCA analysis area includes system boundaries, impact categories, functional units, and data quality criteria. Currently or soon to be, the vast majority of the operations covered by a life cycle analysis of a solar power plant are situated in Europe. Europe is the only continent covered by the analysis since the firms that provided the data have a significant presence there. A solar power plant may operate for around 20 to 25 years. The analysis’s cut-off point will be set at 0.01%. Substances emitted over their life cycle with an effect level less than 0.01% relative to the total impact will thus not be taken into consideration in determining the accuracy of the results.

The second step in the LCA process is the analysis of the set of inputs and outputs. A technological facility’s system structure is shown by its LCI (Life Cycle Inventory). Streams of materials and energy link every process that takes place in a solar power plant’s life cycle. After all the data has been gathered, it will be categorized into unit processes and verified using mass and energy balance. The inputs’ value and size must match the outputs’ value and size. The main materials, auxiliary materials, and water requirements will be the inputs. Conversely, the outputs will be the main product and emissions. Information on crucial operations was obtained through direct communication with the manufacturers of the materials and component parts. Conversely, data pertaining to substances and practices that do not have a substantial impact on the environment will be obtained from the databases of the SimaPro 9.4 software.

The third step of life cycle assessment, life cycle impact assessment, or LCIA, is crucial for assessing how a solar power plant’s life cycle affects the environment. Every methodological variation across LCA approaches is primarily related to the LCIA phase, which comprises both required and optional components. The selection of impact categories, category indicators, classification, and characterization are required components. Nonetheless, normalization, grouping, and weighting are optional components. When conducting analyses, the required elements must be arranged in a precisely defined order.

Interpreting the gathered data is the last step in the Life Cycle Assessment process. The final step of the previously mentioned processes involves summarizing, analyzing, and discussing the received LCI or LCIA data. The interpretation stage forms the basis for inferences and presents a summary of decisions made in accordance with the predetermined parameters and goal.

3.3. Cumulative Energy Demand

The energy demand in the life cycle of an object or process can be calculated using the Cumulative Energy Demand (CED) method. Both renewable and non-renewable sources are included in the CED analysis process. Non-renewable sources are Coal, Gas, Oil, Peat, and Uranium. Renewable sources are geothermal, biomass, wind, solar, and water [36]. The so-called midway indicators are used in the CED model to quantify the possible effects of emissions and extraction [27]. The CED model expresses the energy demand in MJ [27]. A product’s total energy demand is the total amount of energy used in all phases of its life cycle, including extraction, production, exploitation, and post-consumer handling of raw materials and auxiliary components. There are several ways to calculate the primary energy demand. The maximum, average, or minimum calorific value of the primary energy sources—the latter including the evaporation energy of water in flue gases—can be chosen for use in the CED model’s computations. Moreover, it is possible to distinguish between the energy requirements of non-renewable and renewable resources [42].

Since energy demand plays a significant role throughout the life cycle of products or systems and since the general methodology for life cycle assessment and CED determination are very similar, it is believed that CED can be used as an indicator of environmental impact, particularly in the case of energy generation systems [43].

4. Results

Table 3 lists the energy demand values for the studied solar power plant during the course of its life cycle. Every effect category identified by the CED model was taken into account. Two methods were evaluated for the post-consumer management of plastics, materials, and elements: recycling and landfilling. The majority of the energy used in the technical facility under examination during its life cycle comes from fossil fuels, which are non-renewable sources (1.89 × 10⁷ MJ—landfill). Reducing energy consumption across the whole life cycle would be possible with the adoption of recycling procedures for both this area (8.11 × 10⁶ MJ) and other regions. Additionally,

Table 4. Characterization of energy consumption during the course of the examined solar power plant’s life cycle (CED model), accounting for the post-consumer management strategy for materials, plastics, and other elements (unit: MJ) (personal investigation).

No	Element of a Technical Object	Photovoltaic Power Plant
	Waste Scenario	Landfilling	Recycling
	Impact Category
1	Nonrenewable, fossil	1.89 × 107	8.11 × 106
2	Nonrenewable, nuclear	5.34 × 106	2.32 × 106
3	Nonrenewable, biomass	1.31 × 103	1.30 × 103
4	Renewable, biomass	2.49 × 105	1.99 × 105
5	Renewable, wind, solar, geothermal	3.74 × 105	3.60 × 105
6	Renewable, water	1.60 × 107	1.27 × 107
TOTAL		4.09 × 107	2.37 × 107

highlights the sources of energy from which the examined photovoltaic system receives the most energy. These sources include nuclear energy, fossil fuels, and renewable energy derived from water. Figure 4 depicts the overall energy demand estimates for a photovoltaic power plant over its life cycle, accounting for the kind of post-consumer management (recycling and storage). It is evident that the life cycle involving landfilling requires a notably higher energy input than the life cycle involving recycling.

The energy demand values for the examined solar power plant across its life cycle are summarized in

Table 5. Characterization of energy consumption throughout the life cycle of each unit in the examined photovoltaic power plant (CED model), accounting for the post-consumer materials and element management system (landfill) (unit: MJ) (personal investigation).

No	Waste Scenario	Landfilling
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Impact Category
1	Nonrenewable, fossil	9.95 × 105	8.16 × 106	9.48·× 106	2.34 × 105
2	Nonrenewable, nuclear	3.14 × 104	1.99 × 106	3.27 × 106	4.85 × 104
3	Nonrenewable, biomass	2.18 × 102	3.21 × 102	7.63 × 102	1.01 × 101
4	Renewable, biomass	1.05 × 104	7.70 × 104	1.54 × 105	7.57 × 103
5	Renewable, wind, solar, geothermal	3.97 × 103	2.80 × 104	3.40 × 105	2.51 × 103
6	Renewable, water	1.77 × 104	2.08 × 106	1.39 × 107	3.19 × 104
TOTAL		1.06 × 106	1.23 × 107	2.71 × 107	3.24 × 105

and

Table 6. Characterization of energy consumption throughout the life cycle of each unit in the examined photovoltaic power plant (CED model), accounting for the post-consumer materials and element management system (recycling) (unit: MJ) (personal investigation).

No	Waste Scenario	Recycling
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Impact Category
1	Nonrenewable, fossil	9.88 × 105	−9.85 × 105	8.11 × 106	1.47 × 103
2	Nonrenewable, nuclear	2.75 × 104	−6.00 × 105	2.89 × 106	3.05 × 102
3	Nonrenewable, biomass	2.18 × 102	3.21 × 10−12	7.63 × 102	6.35 × 10−2
4	Renewable, biomass	1.05 × 104	4.01 × 104	1.48 × 105	4.76 × 101
5	Renewable, wind, solar, geothermal	3.94 × 103	1.75 × 104	3.39 × 105	1.58 × 101
6	Renewable, water	1.65 × 104	−7.78 × 105	1.35 × 107	2.01 × 102
TOTAL		1.05 × 106	−2.31 × 106	2.50 × 107	2.04 × 103

. Every impact category found in the CED model was considered. Again, two possibilities for post-consumer development were taken into consideration. The life cycle of solar panels (1.23 × 10⁷ MJ—landfill) and the inverter station (2.71 × 10⁷ MJ—landfill) had the largest energy demand. The primary energy source in both situations was non-renewable fossil fuels (8.16 × 10⁶ MJ for PV panels and 9.48 × 10⁶ MJ for the inverter station). Using recycling procedures would enable energy consumption to be decreased throughout each unit’s life cycle within the evaluated technical facility. The overall energy demand numbers for each solar power plant unit across its life cycle are displayed in Figure 5, which also accounts for the kind of post-consumer management (recycling and landfilling). Data collected for two post-consumer management strategies are displayed in Figure 5. All four photovoltaic power plant components’ findings are displayed in the figure. We can identify which element, at each stage of its life cycle, is most detrimental to the ecosystem using this comparison. It is evident how crucial recycling solar panels is to lower the energy usage of photovoltaic power plants throughout their life cycle.

Table 7. Characterization of energy demand throughout the life cycle of the examined solar power plant with regard to the processes involved in the extraction of non-renewable fossil fuels (CED model), accounting for the technique of managing polymers, materials, and components after consumption (MJ as the unit) (personal investigation).

No	Element of a Technical Object	Photovoltaic Power Plant		Emission Area
	Waste Scenario	Landfilling	Recycling
	Substance
1	Coal, brown	1.20 × 106	9.28 × 104	Raw Materials
2	Coal, hard	5.05 × 106	1.64 × 106	Raw Materials
3	Gas, mine, off-gas, process, coal mining/m3	9.29 × 104	2.28 × 104	Raw Materials
4	Gas, natural/m3	5.91 × 106	4.49 × 106	Raw Materials
5	Oil, crude	6.63 × 106	1.85 × 106	Raw Materials
6	Peat	9.53 × 103	1.01 × 104	Raw Materials
7	Remaining substances	5.97 × 102	3.85 × 101	x
TOTAL		1.89 × 107	8.11 × 106

presents the energy demand figures for fossil fuels from non-renewable sources during the life cycle of the solar power plant under analysis (CED model). The two post-consumer management options, recycling and landfilling, were considered. The largest energy consumption was found to be for energy derived from hard coal (5.05 × 10⁶ MJ—storage) and crude oil (6.63 × 10⁶ MJ for the life cycle with management). Recycling techniques would provide a reduction in energy consumption for these two sources (1.85 × 10⁶ MJ for crude oil and 1.64 × 10⁶ MJ for hard coal) as well as the other sources across their whole life cycle. In the domain of activities connected to the extraction of non-renewable fossil fuels, Figure 6 depicts the total values of total energy consumption throughout the life cycle of the examined solar power plant, accounting for the type of post-consumer management (landfilling and recycling). It may be observed that the life cycle involving landfilling requires a notably higher energy input than the life cycle involving recycling.

The values of the fossil fuel energy consumption for each unit of the examined photovoltaic power plant (CED model) are listed in

Table 8. Characterization of energy demand throughout the life cycle of each unit in the examined photovoltaic power plant, with special attention to the processes involved in the extraction of non-renewable fossil fuels (CED model). This is performed while accounting for the post-consumer management strategy used for plastics, materials, and elements (landfill) (unit: MJ) (personal investigation).

No	Waste Scenario	Landfill				Emission Area
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Substance
1	Coal, brown	1.40 × 104	7.23 × 105	4.44 × 105	1.59 × 104	Raw Materials
2	Coal, hard	7.23 × 105	2.33 × 106	1.93 × 106	6.41 × 104	Raw Materials
3	Gas, mine, off-gas, process, coal mining/m3	1.30 × 104	4.67 × 104	3.21 × 104	1.12 × 103	Raw Materials
4	Gas, natural/m3	6.97 × 104	1.60 × 106	4.16 × 106	7.73 × 104	Raw Materials
5	Oil, crude	1.75 × 105	3.47 × 106	2.91 × 106	7.56 × 104	Raw Materials
6	Peat	x	x	9.50 × 103	2.59 × 101	Raw Materials
7	Remaining substances	3.85 × 101	5.58 × 102	x	2.91 × 10−11	x
TOTAL		9.95 × 105	8.16 × 106	9.48 × 106	2.34 × 105

and

Table 9. Energy demand characterization throughout the life cycle of each unit in the examined photovoltaic power plant, with special attention to the processes involved in the extraction of non-renewable fossil fuels (CED model). This is conducted while accounting for the post-consumer management strategy used for plastics, materials, and elements (recycling) (unit: MJ) (personal investigation).

No	Waste Scenario	Recycling				Emission Area
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Substance
1	Coal, brown	1.37 × 104	−2.23 × 105	3.02 × 105	1.00 × 102	Raw Materials
2	Coal, hard	7.23 × 105	−5.74 × 105	1.49 × 106	4.03 × 102	Raw Materials
3	Gas, mine, off-gas, process, coal mining/m3	1.30 × 104	−1.33 × 104	2.31 × 104	7.04 × 100	Raw Materials
4	Gas, natural/m3	6.87 × 104	4.41 × 105	3.98 × 106	4.86 × 102	Raw Materials
5	Oil, crude	1.70 × 105	−6.17 × 105	2.30 × 106	4.75 × 102	Raw Materials
6	Peat	x	5.51 × 102	9.50 × 103	1.63 × 10−1	Raw Materials
7	Remaining substances	3.85 × 101	1.16 × 10−10	−9.31 × 100	1.83 × 10−13	x
TOTAL		9.88 × 105	−9.85 × 105	8.11 × 106	1.47 × 103

. Two post-consumer development scenarios were considered. The life cycle of solar panels (8.16 × 10⁶ MJ—landfill) and the inverter station (9.48 × 10⁶ MJ—landfill) had the largest energy demand. For PV panels, the primary energy sources were crude oil (3.47 × 10⁶ MJ) and hard coal (2.33 × 10⁶ MJ), whereas natural gas (4.16 × 10⁶ MJ) was the primary energy source for the inverter station and 2.91 × 10⁶ MJ of crude oil. Using recycling procedures would enable energy consumption to be decreased throughout each unit’s life cycle within the evaluated technical facility. Figure 7 illustrates the overall energy consumption from fossil fuels for each unit of a solar power plant during its life cycle, including for post-consumer management practices (recycling and landfilling). It is evident how crucial recycling solar panels is to lower the energy usage of PV power plants throughout their life cycle.

The energy demand figures from hydropower plants during the life cycle of the solar power plant under analysis (CED model) are listed in

Table 10. Characterization of energy demand throughout the life cycle of the examined solar power plant, taking into consideration the process of managing polymers, materials, and elements after consumption in the context of activities linked to acquiring energy from renewable sources, such as hydropower plants (CED model) (unit: MJ) (personal investigation).

No	Element of a Technical Object	Photovoltaic Power Plant		Emission Area
	Waste Scenario	Landfill	Recycling
	Substance
1	Energy, potential (in hydropower reservoir), converted	1.60 × 107	1.27 × 107	Raw Materials
2	Remaining substances	x	x	x
TOTAL		1.60 × 107	1.27 × 107

. Both landfill and recycling post-consumer management scenarios were considered. The life cycle involving the management of polymers, materials, and components in the form of landfill storage had the highest energy consumption (1.60 × 10⁷ MJ). Using recycling procedures would lower the total life cycle energy usage (1.27 × 10⁷ MJ). Figure 8 shows the overall values of the energy demand from hydropower plants in the life cycle of the studied solar power plant, taking into consideration the type of post-consumer treatment (recycling and landfilling).

In the area of processes related to obtaining energy from renewable sources—hydropower plants (CED model)—the energy demand numbers from hydropower plants for each unit in the life cycle of the examined photovoltaic power plant, as well as the characterization of energy demand in the life cycle of individual units of the analyzed photovoltaic power plant, are presented in

Table 11. Energy demand characterization throughout the life cycle of each unit in the examined photovoltaic power plant, with a focus on the processes involved in obtaining energy from hydropower plants and renewable sources of energy (CED model) and accounting for the post-consumer management of plastics, materials, and elements (landfill) (unit: MJ) (personal investigation).

No	Waste Scenario	Landfilling				Emission Area
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Substance
1	Energy, potential (in hydropower reservoir), converted	1.77 × 104	2.08 × 106	1.39 × 107	3.19 × 104	Raw Materials
2	Remaining substances	x	x	x	x	x
TOTAL		1.77 × 104	2.08 × 106	1.39 × 107	3.19 × 104

and

Table 12. Energy demand characterization throughout the life cycle of each unit in the examined photovoltaic power plant, with a focus on the processes involved in obtaining energy from hydropower plants and renewable sources of energy (CED model) and accounting for the post-consumer management of plastics, materials, and elements (recycling) (unit: MJ) (personal investigation).

No	Waste Scenario	Recycling				Emission Area
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Substance
1	Energy, potential (in hydropower reservoir), converted	1.65 × 104	−7.78 × 105	1.35 × 107	2.01 × 102	Raw Materials
2	Remaining substances	x	x	x	x	x
TOTAL		1.5 × 104	−7.78 × 105	1.35 × 107	2.01 × 102

. All of these data are taken into consideration when managing plastics, materials, and elements after consumer use. Every impact category found in the CED model was considered. Two post-consumer development scenarios were considered. The life cycle of solar panels (2.08 × 10⁶ MJ—landfill) and the inverter station (1.39 × 10⁷ MJ—landfill) had the largest energy demand. In the examined area, the life cycle of the supporting structure consumed the least energy (1.77 × 10⁴ MJ—landfill). Using recycling procedures would enable energy consumption to be decreased throughout each unit’s life cycle within the evaluated technical facility. In the life cycle of a single solar power plant unit, Figure 9 depicts the total energy demand from hydropower plants while accounting for the kind of post-consumer management (recycling and landfilling). It is evident how crucial recycling solar panels is to lower the energy usage of PV power plants throughout their life cycle.

The nuclear energy demand numbers for the examined photovoltaic power plant (CED model) are listed in

Table 13. Characterization of energy demand throughout the life cycle of the examined solar power plant in the context of nuclear energy production processes (CED model), accounting for the post-consumer handling of polymers, materials, and components (unit: MJ) (personal investigation).

No	Element of a Technical Object	Photovoltaic Power Plant		Emission Area
	Waste Scenario	Landfilling	Recycling
	Substance
1	Uranium	5.34 × 106	2.32 × 106	Raw Materials
2	Remaining substances	x	x	x
TOTAL		5.34 × 106	2.32 × 106

. Both landfilling and recycling post-consumer management scenarios were considered. The life cycle involving the management of polymers, materials, and components in the form of landfill storage had the largest energy consumption (5.34 × 10⁶ MJ). Utilizing recycling procedures would provide a decrease in energy usage during the full life cycle (2.32 × 10⁶ MJ). Figure 10 shows the overall values of the nuclear energy consumption in the life cycle of the studied solar power plant, taking into consideration the type of post-consumer management (recycling and landfilling).

The figures for nuclear energy consumption for each unit in the life cycle of the examined photovoltaic power plant (CED model) are listed in

Table 14. Energy demand characterization throughout the life cycle of each unit in the examined photovoltaic power plant in terms of nuclear energy-related processes (CED model), accounting for the way that materials, plastics, and other elements are managed after consumption (landfill) (unit: MJ) (personal investigation).

No	Waste Scenario	Landfilling				Emission Area
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Substance
1	Uranium	3.14 × 104	1.99 × 106	3.27 × 106	4.85 × 104	Raw Materials
2	Remaining substances	x	x	x	x	x
TOTAL		3.14 × 104	1.99 × 106	3.27 × 106	4.85 × 104

and

Table 15. Energy consumption characterization throughout the life cycle of each unit in the examined photovoltaic power plant in terms of nuclear energy-related processes (CED model), accounting for the recycling of materials, plastics, and other post-consumer waste (recycling) (unit: MJ) (personal investigation).

No	Waste Scenario	Recycling				Emission Area
	Element of a Technical Object	Supporting Structure	Photovoltaic Panels	Inverter Station	Electrical Installation
	Substance
1	Uranium	2.75 × 104	−6.00 × 105	2.89 × 106	3.05 × 102	Raw Materials
2	Remaining substances	x	x	x	x	x
TOTAL		2.75 × 104	−6.00 × 105	2.89 × 106	3.05 × 102

. Two post-consumer development scenarios were considered. The life cycle of solar panels (1.99 × 10⁶ MJ—landfill) and the inverter station (3.27 × 10⁶ MJ—landfill) had the largest energy demand. The supporting structure’s life cycle exhibited the lowest energy consumption in the examined region, consuming 3.14 × 10⁴ MJ (landfill). Using recycling procedures would enable energy consumption to be decreased throughout each unit’s life cycle within the evaluated technical facility. The overall demand for nuclear energy during the course of a single solar power plant unit’s life cycle is depicted in Figure 11, which also accounts for the kind of post-consumer management (landfilling and recycling). It is evident how crucial recycling solar panels is to lower the energy usage of PV power plants throughout their life cycle.

5. Summary

5.1. Conclusions

An examination of real case studies shows that the life cycle of a solar power plant is in line with the principles of sustainable development. Improvement projects must be implemented to reduce the negative effects on the environment and increase the positive ones. The level of energy demand for the examined solar power plant throughout its whole life cycle can be determined using the CED model. Compared to the life cycle with management in the form of recycling (2.37 × 10⁷ MJ), the life cycle with post-consumer management in the form of landfill was characterized by greater total energy consumption (4.09 × 10⁷ MJ). This was influenced by the potential for recycling materials, components, and plastics—particularly copper or solar cells, whose manufacture is linked to exceptionally high energy consumption. Assuming that the annual production of electricity by the analyzed photovoltaic system is approximately 2000–2100 MWh, the power plant must operate for approximately 5.5 years to produce an amount of electricity equal to the total energy inputs during its life cycle, assuming storage as a form of post-consumer management or approximately 3 years, assuming recycling as a form of management of plastics, materials, and elements (Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 10 and Figure 11 and Table 3, Table 4, Table 5, Table 6, Table 7, Table 8, Table 9, Table 10, Table 11, Table 12, Table 13 and Table 14).

The accomplishment of this study’s objective makes it possible to judge the implementation of the chosen methodologies as appropriate and accurate. This study makes it possible to identify the effects on the environment, the economy, and society, as well as to evaluate the advantages and disadvantages of a solar power plant’s life cycle in relation to important areas of sustainable development.

5.2. Discussion

Demand for natural resources and energy is correlated with human activities. Pro-environmental endeavors, such as the manufacturing of wind and solar power plants, require a significant amount of energy and materials. Thus, by applying life cycle assessment (LCA) to their life cycle and considering two post-consumer management options (recycling and landfilling), it is possible to anticipate adverse consequences and restrict their growth in relation to the environment.

Life cycle analyses often focus solely on individual solar panels, not the overall solar power plant. This process restricts the range of indicators that other photovoltaic power plant components can produce that negatively affect the environment. The full photovoltaic power plant—including the electrical setup, solar panels, supporting structure, and inverter station—is examined in our research. These are a solar power plant’s four most crucial operational components. As a result, this work’s breadth serves to highlight a wider issue.

5.3. Main Recommendations

Among other things, the life cycle assessment (LCA) can be conducted at any stage of the system’s life and even after it has been completed, which makes it possible to eco-design novel solutions for high-installed capacity solar systems. The outlined method also provides three sections of the technological product under study with the option of maximizing positive effects and limiting negative ones.

Performing environmental work; altering the design of complete working units and individual elements to facilitate the easier separation of individual materials and avoid identification issues during post-consumer management; implementing cost-effective measures to reduce energy consumption, material consumption, and harmful emissions of production processes; and increasing awareness of the concept of testing and evaluating the impact of photovoltaic power plants and other renewable energy systems throughout their entire life cycle are some of the recommended actions to improve the life cycle of photovoltaic power plants in a sustainable manner.

5.4. Extending the Scope of Research

This study’s scope might be increased to cover more areas that might be affected by dangerous pollution or employ a different approach, as ReCiPe 2016.