Annual Energy Yield Research Articles

Genetic least square estimation approach to wind power curve modelling and wind power prediction

Wind power curve (WPC) is an important index of wind turbines, and it plays an important role in wind power prediction and condition monitoring of wind turbines. Motivated by model parameter estimation of logistic function in WPC modelling, aimed at the problem of selecting initial value of model parameter estimation and local optimum result, based on the combination of genetic algorithm and least square estimation method, a genetic least square estimation (GLSE) method of parameter estimation is proposed, and the global optimum estimation result can be obtained. Six evaluation indices including the root mean square error, the coefficient of determination R2, the mean absolute error, the mean absolute percentage error, the improved Akaike information criterion and the Bayesian information criterion are used to select the optimal power curve model in the different candidate models, and avoid the model’s over-fitting. Finally, to predict the annual energy production and output power of wind turbines, a two-component Weibull mixture distribution wind speed model and five-parameter logistic function power curve model are applied in a wind farm of Jiangsu Province, China. The results show that the GLSE approach proposed in this paper is feasible and effective in WPC modelling and wind power prediction, which can improve the accuracy of model parameter estimation, and five-parameter logistic function can be preferred compared with high-order polynomial and four-parameter logistic function when the fitting accuracy is close.

Comparative Optical Analysis of Imprinted Nano‐, Micro‐ and Biotextures on Solar Glasses for Increased Energy Yield

In modern photovoltaic (PV) systems such as bifacial and building‐integrated PV, a big share of sunlight impinges at large incident angles on the air‐to‐glass module interface. These designs exceedingly call for effective omnidirectional antireflective (AR) measures. Texturing of PV cover glasses can effectively mitigate reflection losses in a broad spectral and angular range. Numerous individual textures have been presented in the literature; however, the lack of consistent material stacks hinders a comparative evaluation. Herein, UV‐nanoimprint lithography is used to fabricate and analyze 12 different artificial and bioreplicated textures from nano‐ to mesoscale on glass. The angle‐resolved reflectance is examined for incident angles from 5° to 80° and analyzed the scattering properties. For example, the effect of the investigated textures on the annual energy yield is calculated for a tilted bifacial PV module located in Berlin, Germany. While well‐known moth‐eye nanostructures exhibit excellent AR behavior near‐normal incidence, their shallow angle performance is often not reported. The best‐performing textures exhibit features on microscale and a large surface enhancement factor, increasing the annual energy yield up to 5% when compared to nontextured devices. The results give clear design guidelines for textured glasses of future PV applications.

Design and optimization of CSP power plants for Pakistan: a comparative study

Abstract Despite having very high solar irradiance, Pakistan still does not have any installed concentrated solar power (CSP) plant. Several studies have shown that multiple locations within the country are suitable for CSP plants, but there is limited availability of comprehensive comparative studies. Therefore, this article presents a comparative analysis of different CSP technologies in Pakistan, focusing on their potential to address the country’s energy crisis. The study evaluates the pros and cons of different CSP technologies at various locations through site assessment, modelling, optimization and economic analysis using the System Advisor Model. Quetta and Nawabshah were selected as the locations for modelling multiple scenarios of 100-MW plants, using central receiver systems, parabolic trough collectors and linear Fresnel reflectors. The plants were integrated with thermal energy storage and the storage capacity was optimized using parametric analysis. The results showed that a central receiver system for the location of Quetta was the most favourable option, with an annual energy yield of 622 GWh at 7.44 cents/kWh, followed by a central receiver system for Nawabshah (608 GWh, 9.03 cents/kWh). This study is the first to show that switching between line-concentrated and point-concentrated CSP technologies can open new opportunities for sites in Pakistan with relatively high solar resources, resulting in a 21.3% reduction in the levelized cost.

Design and Viability Assessment of Grid-Integrated Solar PV System for Electric Power Supply Enhancement: A Case Study of Idofian, Nigeria

Recently, the demand for electric power supply has tremendously increased and the Nigerian government is unable to meet this demand, with conventional energy generation, due to myriads of issues in the electricity sector. A 2 MW grid-integrated solar photovoltaic system design is carried out in this work using Idofian, Kwara State, Nigeria, as a case study. The feasibility study for the Solar PV system along with the load estimation for the study area were done using RETScreen software. The simulation results revealed that the design is feasible for Idofian township, with an annual energy yield of roughly 2,853 MWh, of about 17% of Idofian's annual (daily) electricity consumption. Solar PV electricity generation saves around 1,182.7 tonnes of CO2. The plan, if adopted, will go a long way toward alleviating Nigeria's electricity shortage.

Design Considerations for Vertical Bifacial Agrivoltaic Installations

Abstract The expected annual energy output of vertical bifacial solar panel arrays was modeled with an eye on how array design attributes affect the output. We considered module height, cell density (single- or double-high racking), inter-row spacing, and inverter connection (rows of modules wired together or separately), and the inclusion of bypass diodes. We observed that these design choices have a substantial impact on the annual energy yield on a per-module basis and per-acre basis. We modeled the instantaneous brightness and shading based on the position of the sun and adjacent rows of modules, which caused nonuniform irradiance due to inter-row shading effects. Based on the irradiance, we calculated current, voltage, and power values throughout a year for different design strategies. Double-high racking, which uses two landscape-oriented modules stacked vertically, offers noteworthy power gains per acre with only a modest increase of inter-row shading. When bypass diodes are included in the module design and improved inverter wiring is used, much of the loss due to inter-row shading is mitigated, and the total power output per acre is nearly doubled, with modules seeing an 80% power increase per acre for 20 ft row spacing, and over 90% power increase per acre for 40 ft spacing.

Improving the energy efficiency of wind turbines for charging batteries

The article describes the method for determining the optimal angular velocity and the number of turns of the generator winding on permanent magnets powered by a wind turbine operating in specific operating conditions according to the wind speed regime. The optimization criterion is the maximum potential of energy that can be used to charge the battery. The permissible power of the generator and wind turbine, current and battery charging voltage are accepted as limiting factors. The restriction is provided by connecting a ballast resistor to the generator output. The power developed by the turbine is determined taking into account the wind energy utilization factor, which depends on the angular velocity of its shaft and wind speed. Two variants of power limitation are compared: by limiting the angular velocity by aerodynamic means and by stopping the wind turbine. The return of energy to charging in both cases is determined taking into account the distribution of wind speeds, obeying the Weibull probability distribution law. As an example, the calculation of the possible annual power generation for charging a battery with a capacity of 200 A∙h with a voltage of 24 volts from a synchron generator with a number of poles of 48 driven by a wind turbine with a radius of 2 meters, operating in an area with an average wind speed of 5 m/s. The calculation shows that for the parameters and operating conditions of the electrical installation used in the example, the maximum annual energy output (3.3 × 103 kWh) is observed at optimal 11 turns of the winding at each of the poles of the generator. The deviation of the number of turns from the optimal one in both directions by 2 times leads, with the same dimensions of the wind turbine, to a decrease in annual energy output by 3...5 times, which is a clear proof of the need to carry out such a calculation for each specific wind turbine.

Computing optimum solar tilt angles for photovoltaic applications through python code simulation

AbstractCarrying out the dual objectives of computing the optimized tilt angles for multiple locations in Pakistan along with recommending a generalized approach for the estimation of optimum tilt angle for any location in country, this study was conducted. Python code was developed for the optimization purpose of daily, monthly, seasonally, biannually and annual solar tilt angle. Detailed analysis was presented for one location (Karachi) and a comparative analysis of optimum tilt angle conditions has been conducted for all investigated sites. Daily optimum tilt angles were found to vary from −12.0° to 55.5°. Similarly, monthly optimized tilt angles were found to vary from −11.5° (in June) to 55.0° (in December). Furthermore, seasonal tilt angles were found as 46.0 °, 2.0 °, 0.5 ° and 45.0 ° in winter, spring, summer and autumn respectively. Finally, annual optimum tilt angle (fixed throughout the year) was found as 25.5° (closer to the latitude value of Karachi). It has been found that daily adjustment of tilt angle causes a gain of 6.85% in annual energy yields when compared with fixed angle throughout the year. Similarly, energy gains were found as 0.15%, 1.24% and 6.83%, when tilt angle was adjusted daily as compared to monthly, seasonal and biannual adjustment cases respectively. The optimum tilt angle for three pairs of locations having comparable latitudes were compared and it was found that the sites having comparable latitudes do not have any marked difference in their optimum tilt angle values.

Study of vertically mounted photovoltaic modules and their influence on the production of electrical energy in free-standing photovoltaic systems using PVGIS-CMSAF

The paper inhere explores the impact of the azimuth angle of vertically mounted bifacial photovoltaic modules on annual electricity generation. At the recent years bifacial photovoltaic modules are introduced to the market, opening new opportunities for increasing efficiency of electricity production and decreasing of the space needed for installation. The purpose of the current study is to obtain and evaluate the annual electricity production of bifacial vertically mounted photovoltaic modules in dependence on the orientation. Comparative analysis has been made between the efficiency and annual energy yield of bifacial vertically mounted PV modules and classically installed PV modules. All the calculations and analyses have been made with the aid of the software product PVGIS-CMSAF. Despite of the controversial increase of efficiency of bifacial vertically mounted photovoltaic modules compared to classically installed photovoltaic modules, the study had confirmed some of their advantages: they require less space for installation; can be used also as PV fences or noise barriers; in some cases the land of installation can be cultivated, used for agriculture or animal husbandry.

Techno and economic assessment of dry cooling option for concentrated solar power (CSP) plant in the desert region

The cogency of dry cooled concentrated solar power (CSP) plant to assess its odds or accretion against the wet cooled plant is investigated in this work in hot and cold desert regions. Dry cooling proves to be a flipside option over the wet cooling system in locations where water resource is scarce. In the current work, the Andasol Parabolic trough CSP plant in Spain, which has 50 MWel nominal capacity with thermal energy storage (TES) hours of 7.5 at full load, is considered a reference plant. Simulation is performed for both wet and dry cooling options using Greenius software initially at the original plant location in order to validate results by considering actual plant values. Simulations were performed at Jodhpur and Leh with the help of the local metrological data. The parameters such as annual mean overall efficiency, levelized cost of electricity and water consumption with dry cooling for the reference plant at study site Jodhpur stand at 15.6%, 0.13 €/kW h LCOE, and 74,793 m3/year, respectively, whereas the same for wet cooled reference power plant yields 17%, 0.11 €/kWh LCOE (levelized cost of energy), and 5, 71, 365 m3/year at an annual energy yield of 163.24 GWhel net. The net electricity generation is high at Leh compared to Jodhpur, India. It is observed that dry cooling has given higher turbine efficiency except for the summer season due to very low ambient temperatures in Leh.

A framework to estimate generating capacities of PV systems using satellite imagery segmentation

The growing interest in global warming has led to various efforts to rely on new renewable energy such as solar power. More accurate energy generation calculation is on-demand with the rise of publicly accessible residential photovoltaic (PV) panels. PV panel area computation is the first step towards the image-based estimation of energy generation from the residential solar arrays. Satellite image segmentation provides a low-cost and simple solution to calculate solar panel area installed on rooftops and the ground. The most relevant approach is to acquire high-quality labels rather than network architectures in many scenarios. This research aims to estimate potential solar energy from satellite images using deep learning segmentation techniques. We compared five architectures such as UNet, UNet++, Feature Pyramid Network (FPN), Pyramid Scene Parsing Network (PSPNet), and DeepLabV3, with different encoders. We converted segmented image pixels into square meters regarding the average slope of panels. We considered the average solar panel efficiency, global tilted irradiation, and the loss coefficient to estimate the annual energy output from the calculated area. UNet with the EfficientNetB7 encoder performed the best with a dice similarity coefficient of 0.9982 for segmentation and a Mean Absolute Percentage Error (MAPE) of 3.5 for energy output estimation.

Effects of land-based wind turbine upsizing on community sound levels and power and energy density

Multiple technological, social, and market factors of wind power are evolving rapidly. Most notably, significant wind turbine scaling is occurring and is forecasted to continue. While the larger turbines expected to be deployed in the future are more powerful and efficient, they are also expected to operate at higher sound levels and require larger setbacks than those installed in the last decade. These sometimes-competing deployment trends and impacts cannot be understood via simple extrapolations of past trends. This study analyzes the effect of these future larger turbines on wind turbine micro-siting, project-level power and energy density, and community noise impacts. Due to their taller heights, larger rotors, and higher sound power levels, future wind turbines will require larger setbacks from homes and greater inter-turbine spacing, resulting in fewer turbines deployed for a given land area. This research finds these changes more than offset the effect of the higher turbine sound emissions, significantly decreasing the average sound levels that wind plant hosting communities experience. Yet, simultaneously, plant layouts using future turbine designs also result in projects with higher installed capacities and annual energy output for a given land area. These increases will likely lead to increased tax benefits and local income in the community. The deployment of fewer turbines on a smaller number of parcels could have implications on siting flexibility and landowner payments.

Building integrated photovoltaics powered electric vehicle charging with energy storage for residential building: Design, simulation, and assessment

Global warming poses a serious danger to the environment, animals, and the livelihoods of humans. The residential building sector & transportation sector has received significant attention in recent years due to GHG emissions. Electric vehicles (EVs) are poised to play an essential function in reducing dependency on non-renewable fuels and the transportation sector's environmental implications. On the other hand, the sustainability of EVs depends on their method of charging. This paper investigates the feasibility and design of a BIPV (building-integrated photovoltaic) powered EV charging system in a typical Malaysian house using solar energy to meet residential and EV charging demand. Three BIPV systems: Grid integrated with no battery, grid integrated with 75 % battery storage and grid integrated with 100 % battery storage have been designed, simulated, and assessed for the performance parameters. BIPV plant capacity of 5.6 kWp, roof inclination of 10°, and roof facing southeast and northwest have been sized for the proposed system. The annual energy output was 8.05MWh, 7.21MWh and 7.19MWh for the three scenarios. LCOE of the grid-connected system with no batteries showed the lowest value of 0.16RM/kwh, whereas a system with batteries had higher LCOE of 0.51RM/kWh and 0.65RM/kWh. The grid-connected system without batteries showed the highest GHG emission savings of 137,321,924 kgCO2e.

Roof integrated photovoltaic for electric vehicle charging towards net zero residential buildings in Australia

The residential building sector & transportation sector has received significant attention in recent years due to carbon emissions affecting the livelihoods of humans. Electric vehicles (EVs) are poised to play a vital role in reducing dependency on non-renewable fuels and the transportation sector's environmental implications. Building integrated Photovoltaics (BIPV), on the other hand, will be able to cut down the energy requirements and contribute to building sustainability. This paper evaluates the energy, economic, and environmental performances of BIPV with EV charging system systems for a building in Canberra, Australia. BIPV with EV charging can assist in fulfilling building energy needs, charging electric vehicles, and reducing grid reliance. Different load scenarios were studied to optimize system size. Different panel layouts with orientation have been studied for the 5.0kWp BIPV system, each module rating 355kWp. The annual energy output of the BIPV system was found to vary between 8.56 MWh for layout one and 7.08MWh for layout 3. It was found that the payback back of the proposed BIPV system is 4.46 years, LCOE of 0.074AUD/kWh and EV charging cost of 0.95AUD/100 km. The BIPV with EV charging system could save approximately 160,198 kgCO2e in GHG emissions over its lifespan.

Positive Impact of Red Soil on Albedo and the Annual Yield of Bifacial Photovoltaic Systems in Ghana

The annual yield of bifacial photovoltaic systems is highly dependent on the albedo of the underlying soil. There are currently no published data about the albedo of red soil in western Africa. In this study, the impact of the albedo of red soil in Ghana on the energy yield of bifacial photovoltaic systems is analysed. A bifacial photovoltaic simulation model is created by combining the optical view factor matrix with an electrical output simulation. For an exact simulation, the albedo of red soil at three different locations in Ghana is measured for the first time. The average albedo of every red soil is clearly determined, as well as the measurement span including instrumentation uncertainty; values between 0.175 and 0.335 were measured. Considering these data, a state-of-the-art bifacial photovoltaic system with an average of 19.8% efficient modules in northern Ghana can achieve an annual energy yield of 508.8 kWh/m2 and a bifacial gain of up to 18.3% in comparison with monofacial photovoltaic panels. To summarise, red soil in two out of three locations in Ghana shows higher albedo values than most natural ground surfaces and therefore positively impacts the annual yield of bifacial photovoltaic systems.

Energy yield comparison between monofacial photovoltaic modules with monofacial and bifacial cells in a carport

In the photovoltaic (PV) industry, module manufacturers have begun to install bifacial cells into monofacial modules because of their lower production costs relative to monofacial cells. This is linked mainly to a 65.3% reduction in rear aluminum paste consumption and the corresponding 0.5 cent/wafer cost reduction for M4 (161.7 × 161.7 mm2) size wafers. Therefore, this study compared the performance of monofacial PV modules with the monofacial cells as a reference group and bifacial cells as the test group to determine the cost reduction potential of the latter in terms of energy yield. Fifteen modules of each type were installed in a solar carport system on the Korean Peninsula and recorded irradiance and ambient and module temperature for one year. Throughout the year, irradiance and energy yield exhibited a strong linear correlation. The total annual energy yields of the monofacial and bifacial cells were 1,093.1 and 1,098.9 kWh/kWp, respectively. The energy yield of the bifacial module was 5.8 kWh/kWp (0.53%) higher than that of the monofacial module. Thus, monofacial modules with bifacial cells may be used in the PV industry to reduce cell production costs and levelized cost of electricity while enhancing energy yields and overall product performance in carport systems on the Korean Peninsula during all four seasons.

Performance investigation of seawater desalination system powered by central receiver concentrated solar thermal plant

Seawater desalination using solar energy is a promising solution for addressing water scarcity in arid and semi- arid regions, as it not only provides a reliable source of fresh water, but also utilizes the abundant solar energy resources in the region to power the desalination process in a sustainable way. For this, the aim of this research is to investigate the performance and economic feasibility of a concentrated solar power plant coupled with a desalination unit for sustainable electricity and freshwater production. Six different coastal sites throughout the Middle East and North Africa region were considered, i.e., Agadir (Morocco), Algiers (Algeria), Sharm el-Sheikh (Egypt), Dammam (Saudi Arabia), Salalah (Oman), and Aden (Yemen). The concentrated solar power facility has a 100 MWe net output with two tanks of direct thermal energy storage using wet cooling with seawater as the cooling agent in the condenser; the solar tower model was validated using the Gemasolar power facility in Spain; and the desalination process include a direct-contact membrane distillation (DCMD) system numerically solved using the MATLAB software®, with experimental data used to validate the model. The findings indicate that large-scale central receiver concentrated solar thermal facilities are more competitive in Sharm el-Sheikh, where annual energy output and capacity factor are expected to be 586.28GWh and 67%, respectively, while the cooling water demand is expected to be 1,793,310 m3. The nominal levelized cost of electricity (LCOEnom) is 11.2 ¢/kWh. Furthermore, water production costs are <0.5 $/m3 in Aden, Damman, Sharm el-Sheikh, and Salalah, but >1.0 $ /m3 in Agadir and Algiers. The results obtained indicate that the combination of these two technologies can be a reliable source of power and fresh water for these locations.

Wind energy potential assessment for co-generation of electricity and hydrogen in the far North region of Cameroon

The fast increase of Cameroon population growth rate and the actual shortage of electricity plaguing the country, particularly in remote areas, give rise to great challenges in the energy generation sector. Nowadays, renewable and clean energy sources are used to foster and improve electricity production via hydrogen generation with water electrolysis. This paper therefore scrutinizes the wind energy potential alongside the electricity and hydrogen generation from wind energy for the cities of Kousseri, Kaele, Maroua, Mokolo, Mora and Yagoua in the Far North Region of Cameroon using wind speed data recorded at 10 m, 40 m and 70 m heights for the years 2011–2021. Several performance indicators including the wind power density, wind turbines power output, wind turbines capacity factor, hydrogen production, cost of produced electricity and hydrogen and payback period are utilized to evaluate the techno-economic viability of the system. This assessment was carried out employing twenty-two commercially accessible wind turbines. Our findings revealed that, Kousseri displays the best hydrogen output with yearly hydrogen production ranging from 3.5054 to 53.232 tons of hydrogen. The annual compressed hydrogen to be saved in this region was found to be in the range of 92.5049 to 1404.70 m3. Enercon E-48/800 turbine records the highest capacity factor in all the chosen locations with the lowest cost of energy varying from 0.0578 $/kWh at Kousseri to 0.0838 $/kWh at Mora. The lowest cost of hydrogen was found to be 4.3865 $/kg for Kousseri, 5.5284 $/kg for Kaele, 5.7160 $/kg for Maroua, 5.9439 $/kg for Mokolo, 6.5065 $/kg for Mora and 6.3354 $/kg for Yagoua employing GE 1.5SL turbine. The highest annual energy output of 3193.9, 2738.1, 2488.4, 2393.9, 2153.3 and 2323.1 MWh was acquired at Kousseri, Kaele, Maroua, Mokolo, Mora and Yagoua, respectively. The shortest payback period was found to be 2.9 years which was related to the case where Enercon E-48/800 wind turbine was assumed to be installed at Kousseri. Finally, the maximum CO2 emission minimization to be achieved if electricity produced by wind turbine is utilized in place of oil burning power plant and power plant that burns natural gas as fuel was 885.36 tons of CO2 and 641.60 tons of CO2, respectively.

Impact of torque tube reflection on bifacial photovoltaic single axis tracked system performance.

Among the racking elements of bifacial photovoltaic (PV) single-axis tracked systems, the torque tube (TT) introduces the most shading and reflection, increasing irradiance nonuniformity and electrical mismatch loss. We simulate the impact of TT shading and reflection on the irradiance profiles, electrical mismatch, and energy yield for central bifacial PV modules on one-in-portrait (1P) and two-in-portrait (2P) single-axis trackers. TT reflection increases annual irradiance in 1P and 2P systems by 0.17% and 0.30%, respectively. Overall, TT reflection increases the predicted instantaneous energy yield by up to 0.8% and 0.4%, and the annual energy yield by 0.11% and 0.18% in 1P and 2P systems, respectively.

A Novel Design of a Hybrid Solar Double-Chimney Power Plant for Generating Electricity and Distilled Water

The classical solar chimney offers passive electricity and water production at a low operating cost. However, the solar chimney suffers from high capital cost and low energy output density per construction area. The high capital investment increases the levelized cost of energy (LCOE), making the design less economically competitive versus other solar technologies. This work presents a new noteworthy solar chimney design for high energy density and maximizing water production. This was achieved by integrating a cooling tower with the solar chimney and optimizing the operating mood. The new design operated day and night as a hybrid solar double-chimney power plant (HSDCPP) for continuous electricity and water production. During the daytime, the HSDCPP operated as a cooling tower and solar chimney, while during the night, it operated as a cooling tower. The annual energy output from the cooling towers and solar chimney (i.e., the HSDCPP) totaled 1,457,423 kWh. The annual energy production from the cooling towers alone was 1,077,134 kWh, while the solar chimney produced 380,289 kWh. The annual energy production of the HSDCPP was ~3.83-fold greater than that of a traditional solar chimney (380,289 kWh). Furthermore, the HSDCPP produced 172,344 tons of fresh water per year, compared with zero tons in a traditional solar chimney. This led to lower overall capital expenditures maximizing energy production and lower LCOE.

Experiment and simulation to determine the optimum orientation of building-integrated photovoltaic on tropical building façades considering annual daylight performance and energy yield

Building-Integrated Photovoltaic (BIPV) on vertical façades is a potential PV application in today's buildings. The performance of BIPV on façades is significantly influenced by the façade orientation. For tropical cities, the optimum façade orientation, in terms of maximum energy yield and daylight performance, cannot be simply determined, due to relatively symmetrical sun path throughout the day. This study therefore aims to determine the optimum orientation for BIPV on tropical building façades. To achieve the objective, experiment, modelling, and computational simulation are conducted to evaluate the BIPV energy yield and to predict the indoor daylight performance in a scale-model building with a 105Wp monocrystalline silicon PV, facing each cardinal orientation in Bandung, Indonesia. The South orientation yields practically zero ASE1000,250, providing the best annual daylight performance, and yielding the most desirable value in four out of five daylight metrics. The greatest annual energy yield is at the North orientation, providing 179–186 kWh (95% prediction interval) per year, but with larger uncertainty compared to that at the South, due to direct sunlight occurrence. Based on three different objective functions, the South orientation is considered optimum for placing the BIPV panel on the prototype façade in the location.