Search Results (31)

Solar photovoltaic (SPV) arrays play a pivotal role in advancing clean and sustainable energy systems, with a worldwide total installed capacity of 1.6 terawatts and annual investments reaching USD 480 billion in 2023. However, climate disaster effects, particularly extremely hot weather events, can compromise the performance and resilience of SPV panels through thermal deterioration and degradation, which may lead to lessened operational life and potential failure. These heatwave-related consequences highlight the need for timely inspection and precise anomaly diagnosis of SPV panels to ensure optimal energy production. This case study focuses on intelligent remote inspection by employing aerial radiometric infrared thermography within a predictive maintenance framework to enhance diagnostic monitoring and early scrutiny capabilities for SPV power plant sites. The proposed methodology leverages pre-trained deep learning (DL) algorithms, enabling a deep transfer learning approach, to test the effectiveness of multiclass classification (or diagnosis) of various thermal anomalies of the SPV panel. This case study adopted a highly imbalanced 6-class thermographic radiometric dataset (floating-point temperature numerical values in degrees Celsius) for training and validating the pre-trained DL predictive classification models and comparing them with a customized convolutional neural network (CNN) ensembled model. The performance metrics demonstrate that among selected pre-trained DL models, the MobileNetV2 exhibits the highest F1 score (0.998) and accuracy (0.998), followed by InceptionV3 and VGG16, which recorded an F1 score of 0.997 and an accuracy of 0.998 in performing the smart inspection of 6-class thermal anomalies, whereas the customized CNN ensembled model achieved both a perfect F1 score (1.000) and accuracy (1.000). Furthermore, to create trust in the intelligent inspection system, we investigated the pre-trained DL predictive classification models using perceptive explainability to display the most discriminative data features, and mathematical-structure-based interpretability to portray multiclass feature clustering. Full article

The overhead line (OHL)–cable hybrid transmission line, which connects floating photovoltaic (PV) power plants, needs to be considered regarding whether to block reclosing operations or not. However, due to the weak-feed characteristics of PV inverters, existing methods are difficult to apply in this scenario. This paper proposes a criterion for fault section identification in the transmission lines of floating PV power plants based on traveling wave power and the zero-sequence impedance angle. Firstly, the fault current characteristics of photovoltaic inverters under dual-vector control are analyzed, and the applicability of the sequence component impedance directional criterion in this scenario is discussed. Then, the transmission, refraction, and reflection processes of traveling waves in OHL–cable hybrid lines are analyzed, and a traveling wave energy criterion is designed to determine the fault section. Finally, based on the scope of application of the zero-sequence impedance angle and traveling wave energy criterion, a fault section identification method for the hybrid lines of floating PV power plants is established. A deployment method for the proposed method, based on feeder terminal units (FTUs) at the connection points between the OHL and cable is proposed. This method identifies fault sections through traveling waves and zero-sequence impedance angles, which are unaffected by PV week feed characteristics, can be applied to all the AC fault types, and do not rely on multi-terminal synchronous sampling. The proposed method is verified on a 1MW PV system built in the PSCAD. Full article

South America is a place on the planet that stands out with enormous potential linked to renewable energies. Countries in this region have developed private investment projects to carry out an energy transition from fossil energies to clean energies and contribute to climate change mitigation. The sun resource is one of the more abundant sources of renewable energies that stands out in South America, especially in the Atacama Desert. In this context, South American countries are developing sustainable actions/strategies linked to implementing solar photovoltaic (PV) and concentrated solar power (CSP) facilities and achieving carbon neutrality for the year 2050. As a result, this systematic review presents the progress, new trends, and the road to a sustainable paradigm with disruptive innovations like artificial intelligence, robots, and unmanned aerial vehicles (UAVs) for solar energy facilities in the region. According to the findings, solar energy infrastructure was applied in South America during the global climate change crisis era. Different levels of implementation in solar photovoltaic (PV) facilities have been reached in each country, with the region being a worldwide research and development (R&D) hotspot. Also, high potential exists for concentrated solar power (CSP) facilities considering the technology evolution, and for the implementation of the hybridization of solar photovoltaic (PV) facilities with onshore wind farm infrastructures, decreasing the capital/operation costs of the projects. Finally, synergy between solar energy infrastructures with emerging technologies linked with low-carbon economies like battery energy storage systems (BESSs) and the use of floating solar PV plants looks like a promising sustainable solution. Full article

Photovoltaic energy (PV) is considered one of the pillars of the energy transition. However, this energy source is limited by a power density per unit surface lower than 200 W/m², depending on the latitude of the installation site. Compared to fossil fuels, such low power density opens a sustainability issue for this type of renewable energy in terms of its competition with other land uses, and forces us to consider areas suitable for the installation of photovoltaic arrays other than farmlands. In this frame, floating PV plants, installed in internal water basins or even offshore, are receiving increasing interest. On the other hand, this kind of installation might significantly affect the water ecosystem environment in various ways, such as by the effects of solar shading or of anchorage installation. As a result, monitoring of floating PV (FPV) plants, both during the ex ante site evaluation phase and during the operation of the PV plant itself, is therefore necessary to keep such effects under control. This review aims to examine the technical and academic literature on FPV plant monitoring, focusing on the measurement and discussion of key physico-chemical parameters. This paper also aims to identify the additional monitoring features required for energy assessment of a floating PV system compared to a ground-based PV system. Moreover, due to the intrinsic difficulty in the maintenance operations of PV structures not installed on land, novel approaches have introduced autonomous solutions for monitoring the environmental impacts of FPV systems. Technologies for autonomous mapping and monitoring of water bodies are reviewed and discussed. The extensive technical literature analyzed in this review highlights the current lack of a cohesive framework for monitoring these impacts. This paper concludes that there is a need to establish general guidelines and criteria for standardized water quality monitoring (WQM) and management in relation to FPV systems. Full article

Green hydrogen production is expected to play a major role in the context of the shift towards sustainable energy stipulated in the Fit for 55 package. Green hydrogen and its derivatives have the capacity to act as effective energy storage vectors, while fuel cell-powered vehicles will foster net-zero emission mobility. This study evaluates the potential of green hydrogen production in Power-to-Gas (P2G) systems operated in former mining sites where sand and gravel aggregate has been extracted from lakes and rivers under wet conditions (below the water table). The potential of hydrogen production was assessed for the selected administrative unit in Poland, the West Pomerania province. Attention is given to the legal and organisational aspects of operating mining companies to identify the sites suitable for the installation of floating photovoltaic facilities by 2050. The method relies on the use of GIS tools, which utilise geospatial data to identify potential sites for investments. Basing on the geospatial model and considering technical and organisational constraints, the schedule was developed, showing the potential availability of the site over time. Knowing the surface area of the water reservoir, the installed power of the floating photovoltaic plant, and the production capacity of the power generation facility and electrolysers, the capacity of hydrogen production in the P2G system can be evaluated. It appears that by 2050 it should be feasible to produce green fuel in the P2G system to support a fleet of city buses for two of the largest urban agglomerations in the West Pomerania province. Simulations revealed that with a water coverage ratio increase and the planned growth of green hydrogen generation, it should be feasible to produce fuel for net-zero emission urban mobility systems to power 200 buses by 2030, 550 buses by 2040, and 900 buses by 2050 (for the bus models Maxi (40 seats) and Mega (60 seats)). The results of the research can significantly contribute to the development of projects focused on the production of green hydrogen in a decentralised system. The disclosure of potential and available locations over time can be compared with competitive solutions in terms of spatial planning, environmental and societal impact, and the economics of the undertaking. Full article

The decarbonization goals of each country necessitate the utilization of renewable resources, with photovoltaic (PV) and wind turbine (WT) generators being the most common forms. However, spatial constraints, especially on islands, can hinder the expansion of PV and WT installations. In this context, wave energy emerges as a viable supplementary renewable source. Islands are candidate regions to accommodate wave power resources due to their abundant wave potential. While previous studies have explored the wave energy potential of the Aegean Sea, they have not focused on the electricity production and techno-economic aspects of wave power facilities in this area. This paper aims to fill this knowledge gap by conducting a comprehensive techno-economic analysis to evaluate the feasibility of deploying an offshore wave power facility in the Aegean Sea, Greece. The analysis includes a detailed sensitivity assessment of CAPEX and OPEX variability, calculating key indicators like LCOE and NPV to determine the economic viability and profitability of wave energy investments in the region. Additionally, the study identifies hydraulic efficiency and CAPEX thresholds that could make wave power more competitive compared with traditional energy sources. The techno-economic analysis is conducted for a 45 MW offshore floating wave power plant situated between eastern Crete and Kasos—one of the most wave-rich areas in Greece. Despite eastern Crete’s promising wave conditions, the study reveals that with current techno-economic parameters—CAPEX of 7 million EUR/MW, OPEX of 6%, a 20-year lifetime, and 25% efficiency—the wave energy in this area yields a levelized cost of energy (LCOE) of 1417 EUR/MWh. This rate is significantly higher than the prevailing LCOE in Crete, which is between 237 and 300 EUR/MWh. Nonetheless, this study suggests that the LCOE of wave energy in Crete could potentially decrease to as low as 69 EUR/MWh in the future under improved conditions, including a CAPEX of 1 million EUR/MW, an OPEX of 1%, a 30-year lifetime, and 35% hydraulic efficiency for wave converters. It is recommended that manufacturing companies target these specific thresholds to ensure the economic viability of wave power in the waters of the Aegean Sea. Full article

The transition process from fossil fuels to environmentally friendly renewable energy sources carries the risk of creating new environmental damages. Photovoltaic technology represents one of the alternatives with the least risk of harmful environmental impact. However, this technology has two important drawbacks: the significant land occupation for the installation of PV systems and the uncontrollability of production. By constructing floating photovoltaic plants on hydroelectric reservoirs, both of these problems can be reduced to an acceptable level. Some artificial reservoirs, originally built for hydroelectric power plants, have acquired a significant secondary function as recreational areas and fish breeding sites. Therefore, there is justified resistance from the local community to change the existing appearance and purpose of such reservoirs. This paper proposes a completely new concept of integrating the interests of the local community into such objects. In addition to preserving existing uses, the concept also offers new features. This can make the entire system environmentally friendly and sustainable. This paper details the technology behind the construction of floating photovoltaic power plants on artificial reservoirs and emphasizes their various advantages. These benefits include the non-utilization of cultivable land, the ease of assembly and construction, integration into existing power grids, and the potential to address electricity storage issues. For instance, Buško Lake, covering an area of $55.8$ km², may host $2.93$ km² of installed floating photovoltaic (FPV) facilities, enabling a total installed capacity of 240 MW. With an average of $5.5$ h of daily sunshine, this totals 2007 annual hours, equivalent to a 55 MW thermal power plant. An analysis showed that, with losses of 18.2%, the average annual production stands at 302 $\mathrm{G}$$\mathrm{W}$$\mathrm{h}$, translating to an annual production value of 18 million € at 60 €/MWh. The integration of this production into an existing hydroelectric power plant featuring an artificial reservoir might boost its output by 91%. The available transmission line capacity of 237 MW is shared between the hydroelectric power plant (HPP) and FPV; hence during the FPV maximum power generation time, the HPP halts its production. HPP Orlovac operates a small number of hours annually at full capacity (1489 h); therefore in combination with the FPV, this number can be increased to 2852 h. This integration maintains the lake’s functions in tourism and fishing while expanding its capabilities without environmental harm. Full article

Solar photovoltaic (SPV) arrays are crucial components of clean and sustainable energy infrastructure. However, SPV panels are susceptible to thermal degradation defects that can impact their performance, thereby necessitating timely and accurate fault detection to maintain optimal energy generation. The considered case study focuses on an intelligent fault detection and diagnosis (IFDD) system for the analysis of radiometric infrared thermography (IRT) of SPV arrays in a predictive maintenance setting, enabling remote inspection and diagnostic monitoring of the SPV power plant sites. The proposed IFDD system employs a custom-developed deep learning approach which relies on convolutional neural networks for effective multiclass classification of defect types. The diagnosis of SPV panels is a challenging task for issues such as IRT data scarcity, defect-patterns’ complexity, and low thermal image acquisition quality due to noise and calibration issues. Hence, this research carefully prepares a customized high-quality but severely imbalanced six-class thermographic radiometric dataset of SPV panels. With respect to previous approaches, numerical temperature values in floating-point are used to train and validate the predictive models. The trained models display high accuracy for efficient thermal anomaly diagnosis. Finally, to create a trust in the IFDD system, the process underlying the classification model is investigated with perceptive explainability, for portraying the most discriminant image features, and mathematical-structure-based interpretability, to achieve multiclass feature clustering. Full article

The Kingdom of Saudi Arabia is experiencing a surge in electricity demand, with power generation increasing 4 times in 25 years from 1990 to 2014. Despite the abundant primary renewable energy sources, the country has overlooked them in the past in national energy policies. However, in recent years, renewable energy has become a part of the Kingdom of Saudi Arabia’s energy conservation policy due to climate changes, technological progress, economies of scale, and increased competitiveness in supply chains. The Saudi government has created the King Abdullah City for Atomic and Renewable Energy (KACARE) to develop national strategies for effectively utilizing renewable and nuclear energy. This paper reviews the current state of the art of the renewable energy technologies available on the market and evaluates the installation of renewable energy plants near Saudi Arabia’s East Coast for a new town, focusing on technical rather than economic aspects. The paper provides a wide review of the possible technical solutions to exploit the producibility of different renewable sources, considering the challenging climate conditions typical of desert areas. The analysis of a real case study shows a high availability of wind and solar irradiance that allow a net energy production of 354 and 129 GWh, respectively. In addition, the comparison between a typical ground-mounted photovoltaic (PV) system and an emerging floating PV reveals that for the same installed power, occupied area, and environmental conditions, the latter has a 4% greater performance ratio due to the cooling effect of water. Full article

The Spanish government is a strong advocate of reducing CO₂ emissions and has made a clear commitment to the implementation of renewable energies. As reflected in Spain’s National Energy and Climate Plan (NECP), its objective is to double the current capacity of pumped hydropower storage (PHS) plants by 2030. Therefore, the study presented here is both current and forward-looking. This paper presents the results of the analysis of the technical potential of installing floating photovoltaic (FPV) plants at 25 PHS plants in Spain, i.e., the total capacity of Spanish hydropower plants. The study was conducted using various assessment indicators: the global horizontal irradiance ratio, electrical efficiency ratio, area required ratio, pumping area ratio, volume ratio of water pumped per day, and achievable power ratio. In summary, the following conclusions can be drawn: (i) The global horizontal irradiance ratio indicates whether a FPV plant is economically viable. From this point of view, the Aguayo PHS plant and the Tanes PHS plant are not suitable, as this ratio is very low; (ii) the compliance with the electrical efficiency ratio is flexible, and all hydropower plants meet this criterion; (iii) maximising the use of the assigned grid connection capacity is one of the goals sought by electrical companies when implementing FPV plants at existing PHS plants. The following hydropower plants are not suitable for the implementation of an FPV plant in view of the following: La Muela I, La Muela II, Aguayo, Sallente, Aldeadavila II, Moralets, Guillena, Bolarque II, Montamara, and IP; (iv) if the aim is energy storage, the following hydropower plants are not suitable for the implementation of an FPV plant: the La Muela I, La Muela II, Tajo de la Encantada, Aguayo, Sallente, Aldeadavila II, Conso, Moralets, Guillena, Bolarque II, Tanes, Montamara, Soutelo, Bao-Puente Bibey, Santiago de Jares, IP, and Urdiceto; (v) if the aim is to expand an FPV plant already installed at a PHS plant, the following hydropower plants do not meet this criterion: the La Muela I, La Muela II, Aguayo, Sallente, Aldeadavila, Moralets, Guillena, Bolarque II, Montamara, and IP. There are only eight hydropower plants that meet conditions (i), (iii) and (iv): the Villarino, Torrejon, Valparaiso, Gabriel y Galan, Guijo de Granadilla, Pintado, and Gobantes. Full article

The potential of applying a floating PV (FPV) system in an Italian context (namely, Cecita dam and Mucone hydroelectric power plants) is studied. The additional PV energy production, as well as the effect of non-evaporated water on the productivity of the hydropower plant, is analyzed by varying the basin surface coverage. The simulations highlight that the amount of additional hydroelectricity is quite small if compared to the non-FPV system, reaching about 3.56% for 25% basin surface coverage. However, the annual PV energy production is noticeable even at low coverage values. The expected gain in electricity production in the case of 25% basin surface coverage with the FPV plant rises to 391% of that of the actual hydropower plant. This gain becomes even larger if a vertical axis tracking system is installed and the increase is about 436%. The economic analysis confirms that the production costs (USD/kWh) of FPV systems are comparable to those of land-based PV (LBPV) plants, becoming smaller in the case that a tracking system is installed. In particular, the best solution is the one with 15% coverage of the lake. In this case, the levelized cost of electricity for the LBPVs is 0.030 USD/kWh and for the FVPs, with and without tracking, it is equal to 0.032 and 0.029 USD/kWh, respectively. Full article

Photovoltaic power plants are gaining in popularity and availability every year, resulting in a massive increase in their number and size. However, each such investment involves allocating large land areas, the cost of which may be high. For this reason, there has been an increasing interest in the use of post-industrial wastelands in the form of artificial water reservoirs which often occupy large areas. Because their use as places of recreation can be dangerous for people, it is a cheap alternative for the foundation of a floating photovoltaic power plant. In addition, it has an advantage over the land version in that it is possible to produce a more significant amount of energy by using the sun’s rays reflected from the water’s surface. Despite these undeniable advantages, such a structure poses several technological challenges. This article focuses on the aspect of lightning protection, which is particularly important due to the structure’s location in the open, and also a specific ground type with noticeably different mechanical and electrical characteristics than typical soil. Aspects such as the lightning hazard, arrangement of lightning rods, down conductors, lightning equipotential bonding, and various earthing configurations are discussed. The presented analysis is based on geometric models and simulations made in the Ansys/Maxwell 3D environment and is supplemented with calculations in Matlab/Simulink. Full article

The intermittent nature of the solar resource together with the fluctuating energy demand of the day-ahead electricity market requires the use of efficient long-term energy storage systems. The pumped hydroelectric storage ($PHS$) power plant has demonstrated its technical and commercial viability as a large-scale energy storage technology. The objective of this paper is to analyse the parameters that influence the mode of operation in conjunction with a floating photovoltaic ($FPV$) power plant under day-ahead electricity market conditions. This work proposes the analysis of two parameters: the size of the $FPV$ power plant and the total process efficiency of the $PHS$ power plant. Five $FPV$ plant sizes are analysed: $50\%$ ($S1$), $100\%$ ($S2$), $150\%$ ($S3$), $350\%$ ($S4$) and $450\%$ ($S5$) of the $PHS$ plant. The values of the total process efficiency parameter analysed are as follows: $0.77$ for old $PHS$ plants, and $0.85$ for more modern plants. The number of daily operating hours of the $PHS$ plant is 4 h. These 4 h of operation correspond to the highest prices on the electricity market. The framework of the study is the Iberian electricity market and the Alto Rabagão dam (Portugal). Different operating scenarios are considered to identify the optimal size of the $FPV$ power plant. Based on the measured data on climatic conditions, an algorithm is designed to estimate the energy production for different sizes of $FPV$ plants. If the total process efficiency is $0.85$, the joint operation of both plants with $FPV$ plant sizes $S2$ and $S3$ yields a slightly higher economic benefit than the independent mode of operation. If the total process efficiency is $0.77$, there is always a higher economic benefit in the independent operation mode, irrespective of the size of the $FPV$ plant. However, the uncertainty of the solar resource estimation can lead to a higher economic benefit in the joint operation mode. Increasing the number of operating hours of the $PHS$ plant above 4 h per day decreases the economic benefit of the joint operation mode, regardless of the total process efficiency parameter and the size of the $FPV$ plant. As the number of operating hours increases, the economic benefit decreases. The results obtained reveal that the coupling of floating photovoltaic systems with pumped hydroelectric storage power plants is a cost-effective and reliable alternative to provide sustainable energy supply security under electricity market conditions. In summary, the purpose of this work is to facilitate decision making on the mode of operation of both power plants under electricity market conditions. The case studies allow to find the optimal answer to the following practical questions: What size does the $FPV$ power plant have to be in order for both plants to be better adapted to the electricity market? What is the appropriate mode of operation of both plants? What is the economic benefit of changing the turbine pump of the $PHS$ power plant? Finally, how does the installation of the $FPV$ power plant affect the water volume of the upper reservoir of the $PHS$ plant? Knowledge of these questions will facilitate the design of $FPV$ power plants and the joint operation of both plants. Full article

Among the energy targets of the Vietnamese government, solar energy is expected to become the main source of renewable energy in the future. Solar energy is moving forward, with Vietnam outstripping Thailand and becoming the country that installed the largest capacity of solar power generation in Southeast Asia, reaching 16,362 MW in new installations in December 2021. In this study, we have experimentally analyzed and designed a capacity of 47.5 MW grid-connected photovoltaic plant mounted on the floatation system at Da Mi hydropower reservoir in Binh Thuan province. This was selected to be utilized as the first effort to develop the first large-capacity floating solar power plant on a hydroelectric reservoir in Vietnam. A detailed examination of the electrical analysis, including DC to DC converters, AC inverters to the transmission network, and PV module connectivity configurations, are in scope. The present research has the potential to make a contribution to the design of the DC electrical part, the AC electrical part, and the layout PV modules—Inverter—Floatation system—Floating bridge of FPV plants which are less described in the former articles. The performance of the plant after the first 2 years of operation has confirmed that it has met the expectations and exceeded the investor’s target, with the power output of the first 2 years being higher than the design by 102.58% to 105.59% and no serious damage has occurred to the equipment from 1 June 2019 to 31 August 2021. Full article

In the step-by-step roadmap for limiting and eliminating power sources that use fossil fuel, especially coal-fired power, as well as for setting the Vietnamese government targets for developing renewable energy for replacement, solar farms and rooftop solar power, followed by floating photovoltaic (PV) power, are considered the best candidates for meeting the goals of land space, PV system operation efficiency, and meeting environmental goals. In addition to the rapid development of PV cell technology are the government’s incentives and financial support for PV plants on the water surface area, which is still very large. Floating PV plants will strongly attract investors in the near future. This study could help stakeholders in the market understand the economic–technical aspects from analyzing economic–financial indicators of floating PV plants with a capacity of 47.5 MW connected to the national utility grid 110 kV at Da Mi hydropower reservoir in Binh Thuan province, Vietnam, in May 2019. This is the first floating PV plant on the reservoir in Vietnam, and is the property of a third party. Full article