Annual Energy Generation Research Articles

Design analysis and techno-economic assessment of a photovoltaic-fed electric vehicle charging station at Dhaka-Mawa expressway in Bangladesh

Electric vehicles are crucial for sustainable transport and energy solutions, particularly in developing countries like Bangladesh where their popularity is rising. This study primarily focuses on the techno-economic design of a 300 kWp solar photovoltaic-powered electric vehicle charging station along the Dhaka-Mawa Expressway in Bangladesh, capable of charging 20 electric vehicles simultaneously. The design utilizes the commercially available software package PVsyst 7.2 to ensure the feasibility and efficiency of the charging infrastructure. The use of solar photovoltaics for electric vehicle charging, compared to traditional grid-based methods, offers substantial environmental benefits, including significant reductions in carbon emissions. This shift is driven by decreasing costs, improved module efficiencies, and increased environmental awareness. The estimated levelized cost of energy is calculated at 7.1556 BDT/kWh (BDT is Bangladeshi Taka), with an annual energy generation cost of 1436285.32 BDT. Over a projected lifespan of 25 years, the system is expected to replace 8065 tons of CO2 emissions with its own emissions totaling 537.56 tons, resulting in a net decrease of 6460.2 tons of CO2. This approach not only aligns with Bangladesh’s emission reduction goals but also exemplifies the potential for solar photovoltaic systems to enhance sustainability in transportation. It also emphasizes the importance of integrating renewable energy sources into the electric vehicle-based infrastructure to achieve true sustainability and supports the country’s commitment to combating climate change through technological innovation.

Numerical and Experimental Study on the Performance of Photovoltaic—Trombe Wall in Hot Summer and Warm Winter Regions: Energy Efficiency Matching and Application Potential

Enhancing the energy efficiency of building envelopes is one of the key strategies for energy conservation and reducing consumption in buildings. This study employs numerical research methods to explore the impact of crucial factors such as solar cell coverage, air channel height, indoor relative humidity, and indoor wind speed on the power generation performance and thermal comfort of a photovoltaic (PV)—Trombe wall. The dynamic changes in optical and thermal performance and energy efficiency matching mechanisms of this system are also discussed in hot summer and warm winter regions. The research findings indicate that the periods of good thermal comfort and power generation efficiency for humans are from 9:00 to 17:00 in winter. In summer, these periods are from 5:00 to 8:00 as well as from 17:00 to 20:00. When the system height is 2 m, the electricity price for power supplied by the PV—Trombe wall system is 25% lower than the residential price, with an annual energy generation of 322.5 kWh/m2 of solar panel, which can save USD 6.35 in costs. Moreover, an experiment is conducted to investigate the thermoelectric correlation by constructing a traditional Trombe wall and an external PV—Trombe wall. When the coverage reached 52.08%, the overall system efficiency was maximized. At a coverage of 78.12%, the system’s thermal efficiency was at its lowest, while the maximum power generation was 510.3 W. It can be seen that the PV—Trombe wall possesses good economic benefits and energy saving as well as emission reduction potential in hot summers and warm winters regions, and the smooth implementation of related works will effectively promote its applications and promotions.

Enhancing the performance of an aerosols-affected solar power tower in arid regions: A case study of wind turbines hybridization

The aim of this research is to investigate the effect of the two most important threats to the solar power towers' (SPT) performance, i.e. aerosols' density and water scarcity, on the SPT feasibility in arid regions. The study is the first attempt to include the site adapted aerosols effect on the SPT’s reflected irradiance and comprehensively investigate several new configurations aiming at optimizing the performance and associated costs. Results show that the inclusion of this effect causes an Annual Energy Generation (AEG) reduction of up to 9.1 %. Further, the water consumption analysis is realized based on four different power cycle cooling options, i.e. wet, dry and two hybrid scenarios. Then, a hybridization with Wind Turbines (WT) is proposed as a potential solution to improve the performance of the SPT. The SPT-WT hybridization has been realized with the assistance of an in-house developed algorithm where key design parameters such as solar multiple, thermal energy storage, SPT and WT capacities have been varied over different ranges. It has been found that the configurations with bigger WT share show clear improvements in the Levelized Cost of Energy (LCOE), water consumption and AEG and that’s only when the TES is excluded. However, this comes with a penalty on the capacity factor (CF) which witnesses considerable decreases. The results of this study provide new important information that can be used in conceptual engineering studies and inform policy making.

Hydropower capacity factors trending down in the United States

The United States hydropower fleet has faced increasing environmental and regulatory pressures over the last half century, potentially constraining total generation. Here we show that annual capacity factor has declined at four fifths of United States hydropower plants since 1980, with two thirds of decreasing trends significant at p < 0.05. Results are based on an analysis of annual energy generation totals and nameplate capacities for 610 plants (>5 megawatt), representing 87% of total conventional hydropower capacity in the United States. On aggregate, changes in capacity factor imply a fleetwide, cumulative generation decrease of 23% since 1980 before factoring in capacity upgrades—akin to retiring a Hoover Dam once every two to three years. Changes in water availability explain energy decline in only 21% of plants, highlighting the importance of non-climatic drivers of generation, including deterioration of plant equipment as well as changes to dam operations in support of nonpower objectives.

Optimisation of an On-grid Hybrid Energy System: A Case Study of the Main Campus of the University of Abuja, Nigeria

The challenge of meeting the energy demands of institutions and organisations in an economically viable and environmentally friendly manner is becoming more and more complex especially in developing countries like Nigeria. This work presents a resilient hybrid renewable energy system to supply the electric power requirement of the main campus of the University of Abuja, Nigeria, estimated as 900 kW at a consumption rate of 6300 kWh/day. HOMER software was used as the modelling tool for simulations, optimizations, and sensitivity analyses carried out to explore the feasibility of utilizing Abuja’s (MSW) in hybrid with the mini hydro power potential of River Wuye and solar PV resources to meet the load demand of the campus. The hybrid plant has the following component specifications:hydro resourcenominal flow rate is 14.5 m3/s; maximum head is 10 m and potential capacity is 885 kW;MSW plant specifications were determined to be 500 kW capacity, waste treatment of 2.3 ton/day; lower calorific value for MSW of 15.84 MJ/kg with the solar PV component having a capacity of 500 kW. Total installation cost for the hybrid plant for the 2 MW hybrid plant was determined to be ₦5.44 billion (US$7.225 million) with annual energy generation calculated to be 799,000 kWh/yr. The net present cost for the simulated system was found to be ₦ 9.37 billion ($12,486,120) with the corresponding LCOE being ₦55.2/kWh ($0.0736/kWh). The carbon emission was estimated to be 7.33 g per day which approximates to a net zero emission, demonstrating the environmental friendliness of renewable energy sources utilised. Sensitivity analysis performed on the system using project life span, inflation rate, solar irradiance, MSW’s lower heating value (LHV), capacity shortage and the annual average volumetric flow rate of River Wuye showed that the net present cost increased with increasing plant life while the levelized cost of energy reduces with increasing life from ₦55.02/kWh for plant life of 25 years to ₦43.73/kWh for 30 years.

Techno-Economic Assessment of Molten Salt-Based Concentrated Solar Power: Case Study of Linear Fresnel Reflector with a Fossil Fuel Backup under Saudi Arabia’s Climate Conditions

Concentrated solar power (CSP) has gained traction for generating electricity at high capacity and meeting base-load energy demands in the energy mix market in a cost-effective manner. The linear Fresnel reflector (LFR) is valued for its cost-effectiveness, reduced capital and operational expenses, and limited land impact compared to alternatives such as the parabolic trough collector (PTC). To this end, the aim of this study is to optimize the operational parameters, such as the solar multiple (SM), thermal energy storage (TES), and fossil fuel (FF) backup system, in LFR power plants using molten salt as a heat transfer fluid (HTF). A 50 MW LFR power plant in Duba, Saudi Arabia, serves as a case study, with a Direct Normal Irradiance (DNI) above 2500 kWh/m2. About 600 SM-TES configurations are analyzed with the aim of minimizing the levelized cost of electricity (LCOE). The analysis shows that a solar-only plant can achieve a low LCOE of 11.92 ¢/kWh with a capacity factor (CF) up to 36%, generating around 131 GWh/y. By utilizing a TES system, the SM of 3.5 and a 15 h duration TES provides the optimum integration by increasing the annual energy generation (AEG) to 337 GWh, lowering the LCOE to 9.24 ¢/kWh, and boosting the CF to 86%. The techno-economic optimization reveals the superiority of the LFR with substantial TES over solar-only systems, exhibiting a 300% increase in annual energy output and a 20% reduction in LCOE. Additionally, employing the FF backup system at 64% of the turbine’s rated capacity boosts AEG by 17%, accompanied by a 5% LCOE reduction. However, this enhancement comes with a trade-off, involving burning a substantial amount of natural gas (503,429 MMBtu), leading to greenhouse gas emissions totaling 14,185 tonnes CO₂ eq. This comprehensive analysis is a first-of-a-kind study and provides insights into the optimal designs of LFR power plants and addresses thermal, economic, and environmental considerations of utilizing molten salt with a large TES system as well as employing natural gas backup. The outcomes of the research address a wide audience including academics, operators, and policy makers.

Exploring the Potential of Renewable Energy to Enable Green Hydrogen Production for a Sustainable Future

Abstract – Amidst intensifying concerns about greenhouse gas emissions, the imperative to transition towards sustainable energy solutions is paramount. Renewable energy sources (RES) provide a promising avenue, especially in hydrogen production. In this context, the emergence of “green hydrogen” is pivotal. Green hydrogen is a concept produced using RES like solar and wind energy to power the hydrogen production process. Unlike conventional methods emitting carbon dioxide, green hydrogen is generated through water electrolysis using clean energy. India relies on coal for around 70% of its energy needs, leading to a 29% rise in carbon emissions from 2015 to 2022. Green hydrogen is a potential alternative solution to address the increasing energy demand and the depletion of fossil fuels. Using wind energy for water electrolysis emerges as a suitable method for green hydrogen production. Therefore, in the present study, assessed the potential of hydrogen production using the wind energy resources in five selected locations in India using ERA5 hourly wind data. The investigation further explored the characteristics of wind speeds at these locations using average wind speed, Weibull parameters and wind rose analysis. Using the SUZLON S95 wind turbine, power output and annual energy generation at each location were estimated. Further, estimated the annual hydrogen production and required storage capacity at each location. The results showed a power generation of 891 kW in location Una and 895 kW in Mandvi. Finally, the amount of carbon emissions mitigated due to the use of wind energy sources instead of conventional sources for H2 production is calculated.

Investigating the sustainability of biogas recovery systems in wastewater treatment plants- A circular bioeconomy approach

Advanced wastewater treatment options offer a unique opportunity to recover valuable resources such as energy (biogas), nutrients, and minerals embedded in the wastewater streams. However, considerable challenges remain when designing and planning sustainable wastewater treatment systems. This study aims to evaluate the sustainability of waste-to-energy (WtE) recovery in the form of biogas in a wastewater treatment plant (WWTP). The study investigates the performance of a biogas recovery system in different scenarios and applications from 2018 to 2040, considering the city of Tbilisi in Georgia. The study results reveal a significant biogas production potential, with an average annual energy (heat and power) generation of 137 GWh when biogas is recovered from the wastewater (WW) and sewage sludge (SS). The WWTP-based WtE systems can avoid up to 38,500 tCO2eq emissions every year. The combined recovery (from WW and SS) scenario is financially feasible with a net present value of 14.88 million EUR and a levelized cost of biogas of 0.08 EUR/m³. Recovered biogas can help avoid the usage of 172.34 million m³ of natural gas worth 42.4 million EUR. Sensitivity analysis shows that the quality of wastewater, price of energy, and capital cost of the anaerobic digestion plant are the key factors in determining the economics of WtE recovery systems. This research also demonstrates the interlinkages between sustainable development goals and various benefits of resource recovery systems. This study could be helpful for decision-makers involved in planning and deploying resource recovery systems in a circular bioeconomy approach in WWTPs globally.

Trade-off and synergy analysis between hydropower generation and irrigation development in the Abbay River Basin, Ethiopia

Study region: Abbay River Basin, EthiopiaStudy Focus: This research focused on evaluating the trade-off and synergy between hydropower and irrigation under various development scenarios. The hydro-economic analysis was undertaken to provide insight regarding the benefits received from hydropower and irrigation development scenarios. New hydrological insights for the regionThe research demonstrated the holistic development of water resources for both energy generation and irrigation purposes, thereby maximizing economic benefits while ensuring sustainable water resource management. HEC-ResSim model was found to be adequate for evaluating the power generating capacity of multiple hydropower cascade systems under various irrigation water diversion scenarios. The findings revealed that by focusing solely on hydropower projects without incorporating irrigation development, Abbay river basin would generate up to 38 TWh of annual energy from GERD, Karadobi, Bekoabo and Mandaya cascades, with GERD accounting for 39% of the total output. Under full integration of irrigation development with four hydropower cascades, annual system energy generation was reduced by 12%. Despite the trade-off, the hydro-economic analysis revealed that the combined benefit from hydropower and irrigation surpass the benefits derived exclusively from hydropower only. Under full irrigation development the combined benefit exceeded the benefit obtained solely from four cascade hydropower without irrigation by 94%. The result revealed that simultaneous development of hydropower and irrigation is advisable, rather than prioritizing hydropower projects exclusively over Abbay river basin.

Reservoir Modelling to assess the Releases and Energy Generation for a Projected Scenario of Tarbela Reservoir in Pakistan

Reservoirs are normally formed by the construction of dams across rivers, but off-channel reservoirs may be provided by diversion structures and canals or pipelines that convey water from a river to natural or artificial depressions. The behaviour of the flow due to construction of dam leads to change in a fluvial process leads to deposition of sedimentation in reservoir. In this research, reservoir modelling has been carried out by using HEC-ResSim for Tarbela reservoir in Pakistan. In Pakistan, the Tarbela Reservoir is the largest reservoir on Indus River and it is the backbone of Pakistan’s agriculture sector and economy. The model was calibrated for year 2014 and validated for year 2020 in terms of outflow and power generation. The results show close comparison between simulated and observed outflow and power values for different scenarios. On the basis of 30-year histogram cycle, the future prediction of releases/outflows, power/energy generation in year 2035 has also been made. After 2035, Tarbela reservoir is expected to become the run-off the river type project due to decrease in the gross storage capacity. As per simulated results of the projected scenario (2035), the releases/outflows from reservoir and energy generation will increase in summer season by 7% and 36% respectively and decrease in winter season by 50% and 37% respectively. Further, the reduction in gross storage capacity due to sedimentation would result in the reduction of annual energy generation by 6.5% in year 2035.

Theoretic and experimental performance of a grid-connected photovoltaic system: Multiple prediction model of efficiency and annual energy generation

In this article, the performance of a 3.36 kWp grid-connected photovoltaic system (GCPVS) under warm and subhumid weather conditions and the development of a predictive mathematical model is presented. Climate data of the 2021 year were used to evaluate energy generation, different types of performance, and efficiency. The average annual yield, corrected yield, array, and final yields were 6.45 h/day, 6.18 h/day, 5.16 h/day, and 4.97 h/day, respectively. The overall annual mean capacity factor and efficiency ratios were 20.73% and 77.22%, correspondingly. Experimental data were analyzed and correlated by multivariate linear regression (MLR) prediction and simulation to validate models. The MLR analysis showed that the efficiency is highly dependent on the temperature of the PV modules and that climatic parameters significantly affect the efficiency and output electric power. The prediction models for PV module efficiency, system efficiency, and direct current energy exhibit an uncertainty of ±1.04%, ±0.57%, and ±35.38 kWh, one-to-one. The monthly generation was compared with results obtained by Energy3D simulation-free software, showing an absolute error of ±2.33 kWh. This information can be used as a methodological tool for predicting efficiency and power generation in direct current.

Technical and economic feasibility study of a solar plant on a commercial surface in Azogues, Ecuador.

The submitted paper deals with the shopping mall project that will be supplied with solar power. The selected location was "La Playa Store" shopping center located in the city of Azogues, south of Ecuador. This type of building has at least two characteristics worth studying i) the available surface on the roof, ii) the characteristics of the energy demand curve. This evaluation process establishes the energy requirement of the installation; that is, the energy potential available depending on the surface of its roof, to design a solar plant according to international standards and local ARCONEL 003/18 regulations. The tools used for the involving simulation were the Lumion software, an IFC file created and imported into the Solarius Pv energy simulator, a software specialized in the design of photovoltaic systems. The designed photovoltaic system has a projected annual energy generation of 9,3695.26 kWh; an installed price per watt of $1.1 with viable results at the end of the fifth year of implementation with an IRR of 7.33% and NPV of $390.51. As this is a commercial facility, a constant and flat consumption throughout the day is expected, so implementing solar energy would reduce the actual power requirements by 32.63%

Assessment of direct contact membrane distillation system driven by parabolic trough collector plant technology for electricity and freshwater production: Feasibility and benchmark under different Moroccan climates

Morocco has experienced several years of drought, conventional water resources were insufficient to meet the needs of the population, which prompted the kingdom to seek other resources to ensure the supply of drinking water to this population. The most suitable solution was the desalination of seawater. In this context, the design and investigation of concentrated solar power (CSP) plant integrated with a desalination unit in Morocco are presented in this paper. The CSP part consists of a parabolic trough technology with a two-tank storage system, integrated with a power block of 111 MWe gross consisting of a conventional Rankine cycle. As for the desalination part, it consists of a Direct Contact Membrane Distillation System (DCMD) based on heat and mass transfer equations, and is solved numerically by MATLAB environment; the model was validated by means of the experimental data. The results show that the large-scale Parabolic Trough Collector (PTC) plants are more competitive in Dakhla -southern Morocco- where the annual energy generation and the capacity factor were estimated to be 493.8 GWh, and 47.6%, respectively. Whereas, the Levelized Cost of Electricity (LCOE) is 10.63 ȼ/kWh. Furthermore, it has been found that in the DCMD system, an increase in the feed water temperature leads to an increase in permeate flux. Besides, freshwater production is highest in winters for Dakhla and Agadir (Atlantic Ocean) and it is highest in summers for Saidia and Al Hoceima (Mediterranean Sea). The lowest freshwater production cost is 0.84$/m3 in Dakhla, followed by 0.98$/m3 in Saidia, with the highest production cost at 1.20$/m3 in Agadir.

Optimizing the annual energy yield of a residential bifacial photovoltaic system using response surface methodology

This study investigates the impact of ground albedo, module spacing, height, and tilt angle on the annual energy output of a small-scale residential photovoltaic (PV) system. The study used response surface methodology (RSM) integrated with PVsyst simulation tool for the analysis. The results obtained from PVsyst are verified by comparing them with data from existing literature. Two significant contributions were demonstrated in this study: a parametric analysis that evaluates the influence of several parameters on the annual energy output, and a detailed statistical analysis that utilizes RSM with optimization. The central composite design with 30 runs was used for the experimental design. Within the tested ranges, the findings indicate that ground albedo, module spacing, and module tilt angle significantly affect annual energy generation. The RSM generated a statistical model that predicts the system's annual energy generation, with a determination coefficient (R2) of 0.99. Moreover, the RSM can identify the optimal values of the studied controllable parameters, which can lead to improved system performance and increased energy output. The optimization analysis reveals that the system's highest annual energy output is attained when the ground albedo is set at 0.82, the module spacing is 8.95 m, the module height is 1.35 m, and the module tilt angle is 35.7°. These parameters were determined based on the weather conditions in Sharjah, UAE. The findings reveal that the annual energy production of the tilted bifacial PV (T-BiPV's) improves by 12.4 %, when ground albedo is increased from 0.2 to 0.8. Also, the output increases by 69.47 % when spacing is increased from 2 m to 8 m. Additionally, increasing the height of the T-BiPV modules from 0.5 m to 2 m results in an increase in energy output by 5.63 %. This study can serve as a basis for further investigations into optimizing bifacial PV systems using RSM, particularly under restricted module spacing or when taking land cost into account in the optimization.

Simulation-based analysis of thermochemical heat storage feasibility in third-generation district heating systems: Case study of Enschede, Netherlands

In this article a dual heat storage system comprising thermochemical heat storage (TCS) and hot water storage for managing the mismatch between heat generation and demand in district heating systems (DHs) is evaluated. TCS is known as technology suitable for long-term heat storage due to its high energy density and negligible heat losses over a longer period. However, the integration of TCS in DHs is significantly influenced by the operating conditions of DHs. Here we evaluate the feasibility of integrating TCS into DHs in the Enschede region of the Netherlands. DHs models are established to simulate heat generation, demand, and storage, and a control strategy is designed to manage storage coordination. The obtained results show that the dual storage system outperforms the single hot water storage system in reducing peak load generation. Depending on the TCS's operational condition, annual energy generation from peak load in dual storage systems could drop by 30–60 % compared to the single hot water storage system. It is achieved mainly by managing the energy capacity remaining in the storage system. The technical feasibility and benefits of implementing a TCS system in DHs with a dual storage system are shown to be more energy efficient.

Mitigating El Niño impacts on hydro-energy vulnerability through identifying resilient run-of-river small hydropower sites

Study regionThe Godavari River basin (GRB), situated between the geographical coordinates of 73°21′ E to 83°09′ E and 16°07′ N to 22°50′ N, India Study focusWe developed an integrated framework combining the variable infiltration capacity (VIC) model and geospatial tools to identify potential sites for run-of-river small hydropower plants (RoR-SHP) capable of meeting the GRB's energy demands during El Niño events. This study utilized long-term (1951–2020) daily streamflow data, simulated with the VIC model for design discharge computation at 30%, 75%, and 90% flow dependability and provided a thorough assessment of the potential of RoR-SHP in the GRB. New hydrological insights for the regionThe analysis revealed the GRB's potential for RoR-SHP development, identifying 226 potential sites based on the head along the river, with a combined power and annual energy generation estimate of 92 MW and 0.4 TWh/yr, respectively, at 90% flow dependability. After meticulous screening, 11 potential sites based on the head and the power potential demonstrated a decline of 46.03%, 37.97%, and 17.77% in annual energy at 30%, 75%, and 90% flow dependability, respectively, leaving nine sites maintaining the firm power (90% flow dependability) even during El Niño years. Our findings underscore the increased risk of power shortages during El Niño years and emphasize the need to develop appropriate strategies to cope with the risks associated with El Niño events.

Technical and Financial Viability of a 1 MW CSP Power Plant with Organic Rankine Module: Case Study for a Northeastern Brazilian City

In this study, a 1 MWe parabolic trough concentrating solar power plant using an Organic Rankine Cycle to convert thermal power into electricity was simulated. The solar data used is from Fortaleza, the capital city of Ceara, a state in the northeast region of Brazil. The simulation was year-round and used hourly acquired data. Several different configurations differing in number of collectors and size of thermal energy storage were considered and, by the end of the study, according to the technical and financial results, one best configuration was defined. With a net annual energy generation of 4815.50 MWh, a 12.08% total efficiency and a levelized cost of electricity (LCOE) of 186.98 US$/MWh, the best defined configuration was the one with 100 collector assemblies and 48 MWh storage system. Besides that, the capital and OM costs of the various components were compared to define the most expensive to the power plant, being the collectors acquisition the biggest cost, which represents 74% and 58% of capital and OM costs respectively.

Multi-objective evolutionary optimization of photovoltaic glass for thermal, daylight, and energy consideration

The potential of fenestration systems is increased by incorporating photovoltaic technology into windows. This recently developed technology enhances the ability to generate energy from the building façade, improve the thermal and daylight performance of buildings, and visual comfort of occupants. Integrating an evolutionary optimization algorithm into this technology is one of the possible sustainable solutions to enhance building performance and minimize environmental impact. This paper uses a genetic evolutionary optimization algorithm to explore the optimum performance of photovoltaic glass in an architecture studio regarding annual energy consumption, energy generation, and daylight performance. Design variables include a window-to-wall ratio (i.e., window size and location) and amorphous-silicon thin-film solar cell transparency to generate optimum Pareto-front solutions for the case building. Optimization objectives are minimizing annual thermal (i.e., heating and cooling) loads and maximizing Spatial Daylight Autonomy. Optimized results of low-E semi-transparent amorphous-silicon photovoltaic glass applied on the façade show that the spatial daylight autonomy is increased to 82% with reduced glare risk and higher visual comfort for the occupants. Photovoltaic glass helped reduce the selected room's seasonal and annual lighting loads by up to 26.7%. Lastly, compared to non-optimized photovoltaic glass, they provide 23.2% more annual electrical energy.

Potential of agrivoltaics systems into olive groves in the Mediterranean region

Agrivoltaics systems have emerged as an approach to alleviate competition for land use between food and energy production. Conducting a thorough analysis of the impact that shading from PV modules can have on crops is crucial for the correct design of the system, as excessive shading can lead to important crop yield reductions. This paper focuses on integrating agrivoltaics systems within super-intensive olive groves in the Mediterranean region. A dual model is used to calculate the suitable transparency of PV modules, representing the area not occupied by PV cells. This model customizes the results based on the site's meteorological parameters and the photosynthetic light-response curve of the olive cultivar. The results indicate that transparency levels vary between 0.57 and 0.71, with the lowest values observed in locations with higher solar radiation, such as Egypt and Tunisia. Using these transparency values and typical 20%-efficiency monocrystalline silicon modules, the annual average energy generation per m2 in the selected locations is 65.9 kWh. Another finding reveals that optimizing the model by considering only the months corresponding to the olive growth cycle can reduce the required transparency, thereby increasing the installed PV capacity by up to 3.5%. Furthermore, the potential deployment of these systems is evaluated in terms of installed PV capacity, energy generation, CO2 emissions and job creation. The calculations show that installing agrivoltaics systems into 1% of the total olive surface area in the Mediterranean region would: (i) result in a 2.5% increase in the global PV capacity, (ii) generate 1.8% of the current electricity demand in the selected Mediterranean countries, (iii) avoid the emissions of 4 Mt. (CO2) per year, and (iv) create around 560,000 jobs.

Optimal selection of time windows for preventive maintenance of offshore wind farms subject to wake losses

AbstractThe maintenance of wind farms is one of the major factors affecting their profitability. During preventive maintenance, the shutdown of wind turbines causes downtime energy losses. The selection of when and which turbines to maintain can significantly impact the overall downtime energy loss. This paper leverages a wind farm power generation model to calculate downtime energy losses during preventive maintenance for an offshore wind farm. Wake effects are considered to accurately evaluate power output under specific wind conditions. In addition to wind speed and direction, the influence of wake effects is an important factor in selecting time windows for maintenance. To minimize the overall downtime energy loss of an offshore wind farm caused by preventive maintenance, a mixed‐integer nonlinear optimization problem is formulated and solved by the genetic algorithm, which can select the optimal maintenance time windows of each turbine. Weather conditions are imposed as constraints to ensure the safety of maintenance personnel and transportation. Using the climatic data of Cape Cod, Massachusetts, the schedule of preventive maintenance is optimized for a simulated utility‐scale offshore wind farm. The optimized schedule not only reduces the annual downtime energy loss by selecting the maintenance dates when wind speed is low but also decreases the overall influence of wake effects within the farm. The portion of downtime energy loss reduced due to consideration of wake effects each year is up to approximately 0.2% of the annual wind farm energy generation across the case studies—with other stated opportunities for further profitability improvements.