Solar Energy Resource Assessment Research Articles

Ensemble Machine-Learning Models for Accurate Prediction of Solar Irradiation in Bangladesh

Improved irradiance forecasting ensures precise solar power generation forecasts, resulting in smoother operation of the distribution grid. Empirical models are used to estimate irradiation using a wide range of data and specific national or regional parameters. In contrast, algorithms based on Artificial Intelligence (AI) are becoming increasingly popular and effective for estimating solar irradiance. Although there has been significant development in this area elsewhere, employing an AI model to investigate irradiance in Bangladesh is limited. This research forecasts solar radiation in Bangladesh using ensemble machine-learning models. The meteorological data collected from 32 stations contain maximum temperature, minimum temperature, total rain, humidity, sunshine, wind speed, cloud coverage, and irradiance. Ensemble machine-learning algorithms including Adaboost regression (ABR), gradient-boosting regression (GBR), random forest regression (RFR), and bagging regression (BR) are developed to predict solar irradiance. With the default parameters, the GBR provides the best performance as it has the lowest standard deviation of errors. Then, the important hyperparameters of the GRB are tuned with the grid-search algorithms to further improve the prediction accuracy. On the testing dataset, the optimized GBR has the highest coefficient of determination (R2) performance, with a value of 0.9995. The same approach also has the lowest root mean squared error (0.0007), mean absolute percentage error (0.0052), and mean squared logarithmic error (0.0001), implying superior performance. The absolute error of the prediction lies within a narrow range, indicating good performance. Overall, ensemble machine-learning models are an effective method for forecasting irradiance in Bangladesh. They can attain high accuracy and robustness and give significant information for the assessment of solar energy resources.

Assessment of solar radiation resource from the NASA-POWER reanalysis products for tropical climates in Ghana towards clean energy application

In order to expand the output of solar power systems for efficient integration into the national grid, solar energy resource assessment at site is required. A major impediment however, is the widespread scarcity of radiometric measurements, which can be augmented by satellite observation. This paper assessed the suitability of satellite-based solar radiation resource retrieved from the NASA-POWER archives at 0.5^circ times 0.5^circ spatial resolution over Ghana–West Africa, to develop a long-term source reference. The assessment is based on the criteria of comparison with estimations from sunshine duration measurement for 22 synoptic stations. Overall, the satellite-based data compared well with ground-based estimations by r = 0.6–0.94 ± 0.1. Spatiotemporally, the agreement is strongest over the northern half Savannah-type climate during March–May, and weakest over the southern half Forest-type climate during June–August. The assessment provides empirical framework to support solar energy utilization in the sub-region.

Development of High Resolution Cloud Cover Climatology Databank Using Merged Manual and Satellite Datasets over Ghana, West Africa

ABSTRACT Accurate and reliable total cloud cover (TCC) observation is essential for astronomy, renewable energy resource assessment, climate impact studies, and agriculture. In order to improve the spatial coverage for a climatological distribution pattern of TCC observation across different climatic zones in Ghana – West Africa, this paper developed a merged database comprising ground-based manual TCC observation dataset (TCCM) at 22 tropical synoptic stations and satellite-based TCC dataset retrieved from the NASA Prediction of Worldwide Energy Resource (POWER) climatological archives (TCCN) spanning 30 years (1983–2013) for each dataset. Firstly, the satellite data was assessed statistically for merging with station data. From the results, it is shown that on the overall, the satellite data (TCCN) is a good representation of local TCC climatology comparative to station observation by a mean percentage deviation of 7.8 ± 1.7, and indices of agreement between 0.7 and 0.99 ± 0.01, indicating strong zonal and seasonal similarities. Moreover, the best station-by-station similarities are over the northern half, being predominantly Savannah climate areas, while the southernmost half show the weakest similarities. This can be attributed to a complex interplay of coastal ocean-land-atmosphere interactions obstructing satellite sensing. Finally, the gridded merged dataset established that December–February is the lowest TCC season countrywide, whereas June–August is the highest TCC season, more pronounced over the southern half, being predominantly Forest climate type and showing significant non-linearity with atmospheric clarity indices. The results have useful applications for solar energy resource assessment, crop yield models, and provides a framework for development of cloud property and cloud radiative effect assessment for climate related studies.

Evaluation of MERRA-2 hourly surface solar radiation across China

Accurate global horizontal irradiance (GHI) is key to solar energy resource assessment and prediction. The GHI provided by MERRA-2 (Version 2 of the Modern-Era Retrospective Analysis for Research and Applications) still needs to be evaluated over China. In this study, GHI observed by 37 ground stations in 2018 are used to systematically assess the MERRA-2 GHI performance for all-sky, clear-sky and cloudy days. Moreover, aerosol and cloud products from MERRA-2 are compared with satellite counterparts to determine the dominant factor affecting MERRA-2 GHI. The results show that MERRA-2 overestimates the hourly and daily mean GHI by 69.35 W/m2 and 27.54 W/m2 on all-sky days, respectively. The mean bias error and root mean square error of hourly GHI between MERRA-2 and CERN are 4.98 W/m2 and 124.85 W/m2 on clear-sky days and 107.16 W/m2 and 215.24 W/m2 on cloudy days, respectively. These values indicate a much greater overestimation of MERRA-2 GHI on cloudy days than on clear-sky days. By comparing cloud fraction (CF) and aerosol optical thickness (AOD) between the Moderate-resolution Imaging Spectroradiometer (MODIS) and MERRA-2, we find that the overestimation of MERRA-2 GHI in most areas is induced by the substantial underestimation of MERRA-2 CF. MERRA-2 underestimates AOD in North China and further enhances the overestimation of GHI caused by the underestimation of MERRA-2 CF, whereas the overestimation of AOD in the Sichuan Basin and Southeastern China partly counterbalances the overestimation of GHI caused by the underestimation of MERRA-2 CF.

Imdaa Regional Reanalysis: A New Source of Information for Wind and Solar Energy Resource Assessment Over India

Imdaa Regional Reanalysis: A New Source of Information for Wind and Solar Energy Resource Assessment Over India

Assessment of global solar resource development

With the increasing severity of environmental problems, many countries have set energy transition targets to promote the realization of the Paris Agreement. There has been a global consensus on utilizing solar energy resources as alternatives to conventional sources to support this energy transition. In this regard, analyzing the “location,” “quantity,” and “quality” of global solar energy resources will not only assist an individual country to efficiently utilize these resources but also promote the realization of large-scale intercontinental resource utilization and complementation. This study established the basic database, model methods, and platform tools for global solar energy assessment, Then, a global solar energy resource assessment was conducted, which included the theoretical reserves (TRs), technical installed potential capacity (TPIC), and average development cost (ADC). A comparative analysis of the assessment results for all continents was also performed. After that, based on big data analysis and geographic information system (GIS) calculations, the distribution characteristics of the global solar power TPIC were calculated with the two core indicators, namely the capacity factor and ADC. Furthermore, a data-driven quantitative evaluation of the refined development potential of solar energy resources was performed. Finally, the reasonableness and coincidence analysis of the resource assessment results were verified using data from global and specifically Chinese photovoltaic (PV) bases.

Research on solar energy resource assessment and development pathway in Singapore

Solar energy is the only renewable energy source likely to be developed on a large scale in Singapore. Singapore has limited land resources. According to the land use, the solar energy exploitable areas can be divided into five categories: rooftop photovoltaic, building surface photovoltaic, land-based photovoltaic, floating photovoltaic and infrastructure photovoltaic. The total development area of each type of photovoltaic is about 3,680 × 104 m2. According to the assessment, Singapore has about 968 × 104 kW in 2050, of which distributed solar energy accounted for about 74%. Roof, building and infrastructure photovoltaic mainly adopt distributed development with high cost of per kWh; land-based and floating photovoltaic mainly adopt centralized development with low cost. According to the cost reduction speed and development degree of various kinds of solar energy, two solar energy development paths from 2030 to 2050 are proposed, namely, the full development path and the economic development path. The full development path aims at the full development of solar energy potential, and the economic development path considers the kilowatt-hour cost of solar energy development. The difference between the two paths focuses on the development degree of rooftop photovoltaic and building surface photovoltaic. Under the full development path, the electrification level reaches 61%, 16 percentage points higher compared with the economic development path; the installed renewable energy capacity reaches 51%, 19 percentage points higher compared with the economic development path. On the basis of two solar energy development paths, two 2050 energy scenarios adapted to different solar energy development paths are proposed. Singapore is unable to be carbon neutral in either development path or needs to increase transnational transmission.

Enhancement and validation of building integrated PV system: 3D modelling, techno-economics and environmental assessment

The incorporation of photovoltaic elements in buildings have been gaining more mileage in recent times. Building integrated photovoltaic (BIPV) technologies are on the rise in terms of efficiency and longevity, with a compound annual growth rate (CAGR) of 15.7 % since 2018. The costs of production and raw materials of BIPV have reached a level that is economically beneficial for building developers to adopt the technology. However, the lack of infrastructure as compared to traditional means of energy production has impeded the maturing of such technologies. The issue of conversion efficiency and module degradation have been addressed but not completely resolved by the scientific community. Although attractive governmental incentives such as net energy metering (NEM) and better returns of investments are shifting the tide as of late, what remains to be seen is the mass adoption of BIPV technology in residential and commercial infrastructure. This work aims to develop an optimal layout for photovoltaic panels in the university building precise 3D modelling and solar energy resource assessment. The method adopted is based on energy production capability of a 3D modelled BIPV system which will be carried out in three stages. They are i) Assessment of geographical location and meteorological data, ii) Development of 3D model and orientation analytics and (iii) Development of optimal PV layout. Three systems were considered for this study, which is the roof and two systems on the Southern Façade. The proposed rooftop BIPV design is expected to provide 49.27 % of the building's energy consumption while reducing CO2 emissions by 20155.32 tonnes throughout the lifespan of the system's deployment. This paper serves as a pioneering study on the feasibility of a BIPV system through the incorporation of building geometry for computations on incident solar irradiation. Through the reduction of electricity imported from the grid, the adoption of the BIPV system also serves as an incremental step towards achieving Net Zero Energy Building (NZEB) status for HWUM.

Веб-картографирование ресурсов солнечной энергии Якутии

It is cost effective and environmentally rational to develop renewable energy source in sthe territories of decentralized energy supply, since it allows replacing diesel power generation. Yakutia has a high potential for the development of solar energy and 64 % of its area is in the zone of decentralized energy supply. The features of web mapping—interactivity, multiscale and availability—are useful for assessment of big multi-temporal data on solar resources at the regional scale. Web mapping shows one parameter for Yakutia—all sky insolation incident on a horizontal surface per day per square meter. The parameter is used to assess the potential of solar energy resources in the territory. Initial data comes from the Surface meteorology and Solar Energy archive of the NASA Prediction of Worldwide Energy Resource—SSE NASA POWER project. It includes monthly and annual average global grids for each year from 1984 to 2018. The web application allows users to map the data by grid points, by administrative units and by watersheds. Users can interactively set a period with an accuracy of a month and a territorial division for drawing up a map. The web-based mapping application allows users to create about 50,000 web maps in total. The number based on query combinations available to the user. A large amount of data used for web mapping requires the development of an information system for the dynamic delivery of data at the user’s request. Data preprocessing algorithm helps efficiently aggregate data “on-the-fly” for various territorial units. The DeckGL cartographic library gives high-performance visualization of big spatial data in the browser. We use PostgreSQL and Flask software to develop the information system. Web mapping is useful for the assessment of solar energy resources specifically at the regional level. Interactive tools provided by the web-based mapping applications deepen the analytical content of the cartographic work. There are notable changes in the data preparation through the design of web-based mapping applications in comparison with regular maps.

Research of the variable natural potential of the wind and energy energy in the northern strip of the ukrainian carpathians

The expediency of studying the varying potential of wind and solar energy in the northern strip of the Ukrainian Carpathians is substantiated. The technique of conducting experiments to determine the natural potential of wind and solar energy is proposed and a model for determining the relative volumes of electricity generation by wind farms and solar electrical installations is developed. Based on the conducted research, according to the Drohobych meteorological station, an energy assessment of wind and solar energy resources in the northern strip of the Ukrainian Carpathians was performed. It is substantiated that the theoretical curves of distribution of wind velocity in separate quarters of the year in the territory of the northern strip of the Ukrainian Carpathians are described by the Weibull distributions. Based on the calculations, it is established that the highest total daily solar radiation is in the summer months. Daily graphs of the relative generation of electricity by wind farms and solar electric installations have been constructed. The expediency of formation of combined systems of energy supply of objects from wind and solar energy in the northern strip of the Ukrainian Carpathians has been established. The substantiated patterns of change in the natural potential of wind and solar energy, as well as the graphs of the relative generation of electricity from them, will significantly speed up managerial decisions and improve their quality.

Meteorological Risk Assessment of Rooftop Solar Resource Development in Inner Mongolia

Due to the long and narrow regional characteristics of Inner Mongolia, there are obvious climatic differences between the east and the west, and various meteorological factors have different influences on the development and utilization of solar energy. The abundance and stability index of solar energy resources are relatively high in the central and western region of Inner Mongolia, but there are more sandstorms, high temperature and strong wind. The eastern region is greatly affected by cloud cover, relative humidity and snowfall, which weakens the solar radiation. Through the comprehensive evaluation of the solar energy resources and meteorological elements, it is found that from the Alashan League to the west of Xilin Gol League, and the most of the Chifeng City are low-risk areas, which are relatively suitable for the development and utilization of rooftop solar energy. The central and northern areas of hulunbuir are high-risk areas, which is not suitable for that. Based on the meteorological industry standard “Solar Energy Resource Assessment Method”, we calculate the solar energy resources abundance and stability index, combined with the annual surface meteorological data of 119 meteorological stations in Inner Mongolia from 1988 to 2018. The distribution characteristics of solar energy resources and meteorological elements in Inner Mongolia is analyzed and the suitability and meteorological risks of rooftop solar resources development and utilization are evaluated.

Analysis and research on quality control method of global radiation observation data

Radiation observation data are important basic data for assessment and research of climate change and solar energy resources. Quality control of radiation observation data is an important guarantee for accurate and reliable observation. First, the global radiation data collection method and the quality control process are introduced, and the differences and similarities between different quality control standards are compared in detail. Then, the quality control contents of the upper and lower limits and the rate of change are analysed theoretically and verified by experiments. Theoretical analysis and experimental results showed that the lower limit of the global radiation irradiance quality control should be −20 W/m2, the upper limit should be 2221 W/m2 or based on solar position, and the wrong change rate of sampling value should be 1000 W/m2. Through the unification of the global radiation quality control standards, the difference caused by the inconsistent quality control methods can be avoided, thus improving the effectiveness of the radiation observation data and ensuring the accuracy and consistency of the radiation observation data.

High-resolution assessment of solar energy resources over the Arabian Peninsula

This study presents a high-resolution spatial and temporal assessment of the solar energy resources over the Arabian Peninsula (AP) from 38 years (1980–2017) reanalysis data generated using an assimilative Weather Research and Forecasting Solar model. The simulations are performed based on two, two-way nested domains with 15 km and 5 km resolutions using the European Centre for Medium-Range Weather Forecasts as initial and boundary conditions and assimilating most of available observations in the region. Simulated solar energy resources, such as the Global Horizontal Irradiance (GHI), Direct Normal Irradiance (DNI), and the Diffusive Horizontal Irradiance (DHI), are first validated with daily observations collected at 46 in-situ radiometer stations over Saudi Arabia for a period of four years (2013–2016). Observed and modelled data are in good agreement with high correlation coefficients, index of agreements, and low normalized biases.The total mean annual GHI (DNI) over the AP ranges from 6000 to 8500 Wh m−2 (3000 to 6500 Wh m−2) with significant seasonal variations. The diffuse fraction (the ratio of the DHI to the GHI) is high (low) over the northern (southern) AP in winter whereas it is high (low) over the central to southern (northern) AP during summer, indicating a significant modulation of the sky clearness over the region. Clouds over the northern AP in winter and the aerosol loading due to desert dust over the central and southern AP in summer are the major factors driving the variability of the DHI. The effects of dust and clouds are more pronounced in the diurnal variability of the solar radiation parameters. Our analysis of various solar radiation parameters and the aerosol properties suggest a significant potential for solar energy harvesting in the AP. In particular, the southeastern to northwestern Saudi Arabia are identified as the most suitable areas to exploit solar energy with a minimum cloud coverage over the region.

Comparative Analysis on the Applicability of Different Typical Year Generating Methods in Solar Energy Resource Assessment

Comparative Analysis on the Applicability of Different Typical Year Generating Methods in Solar Energy Resource Assessment

湖南安乡县太阳能资源分布特征及初步评估

根据中国气象局发布的气象行业标准《太阳能资源评估方法QX/T89-2008》，基于多年长沙气象站的太阳总辐射、武汉气象站的直接辐射以及安乡气象站的日照时数资料，对湖南省安乡县1962~2015年太阳能资源分布特征进行了分析，并对该地区的太阳能资源进行了评估。结果表明：安乡地区年太阳总辐射量和直接辐射量呈减少的趋势，太阳散射辐射量呈增加的趋势，且三者均表现为夏季最多，春秋次之，冬季最少；对该地区太阳能资源的评估表明，安乡县属于太阳能资源丰富地区，且太阳能资源较稳定，其太阳能资源可利用平均天数为166.3天。 According to the solar resource assessment methods released by China Meteorological Adminis-tration, many years of the total solar radiation data about Changsha meteorological station, the direct radiation data about Wuhan station and the sunshine hours data about Anxiang station, this study analyzed the distribution and the richness, stability and availability of solar energy resources in Anxiang County of Hunan Province since 1962 to 2015. The results showed that, the overall annual total solar radiation and direct solar radiation in Anxiang tended to decrease since 1962, the diffuse radiation tended to increase. The quantity of radiation is the most in summer, the second in spring and autumn, and the least in winter. The assessment of solar energy resources in this region shows that Anxiang County is a rich area of solar energy resources, and solar energy resources are more stable. The average available days of solar energy resources are 166.3 days in this region.

ACTINOMETRIC DATA FOR THE DESIGN OF SOLAR POWER IN THE MOSCOW REGION

The work is devoted to assessment of solar energy resources for the territory of Moscow. The authors consider the various sources of input data on the incoming solar radiation - the long-term ground-based measurements and spe cialized data bases (NASA POWER). Verification of the NASA POWER data on the base of observations of weather stations in the Moscow region should justify its use under the calculation of resources and performance prediction of solar power plants. The work shows and discusses the results of calculations of solar energy potential on this territory.

Estimating the potential for solar energy utilization in Chile by satellite-derived data and ground station measurements

The progress in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning more than three years of data, satellite estimations from the recently developed Chile-SR model including three full years of data, and simulations that evaluate the potential for solar thermal, photovoltaics (PV) and concentrated solar power (CSP) utilization.The satellite estimation model adapts the Brasil-SR methodology with the combined use of visible and infrared (IR) satellite images, an enhanced treatment for altitude-corrected meteorological variables and an effective cloud cover computations that allows the estimation of the global horizontal and diffuse horizontal irradiation on an hourly basis. Direct normal irradiation (DNI) is computed from the direct horizontal irradiation by applying the Boland–Ridley–Laurent (BRL) model of diffuse fraction and proper solar geometry corrections. Comparison of the satellite-derived data with the ground station data shows good agreement and low error levels thus served for model validation. The results indicate that Chile is endowed with one of the highest levels of solar resource in the world in terms of annual irradiation for large portions of its territory. There is a small decrease in yearly levels of GHI and DNI with latitude that in practice indicate that most of the country shares exceptional conditions for solar energy. However, coastal regions have a large decrease in both GHI and DNI due to the persistence of seasonal cloud covers with daily cycles.The use of irradiation data from the Chile-SR model for system simulation indicates that solar fractions over 80% are achievable for residential-sized solar thermal systems in most of the country, with PV systems yielding between 4.5 and 8kWh/kWpv, and CSP annual yields of up to 240GWh/year for a 50MW parabolic trough plant. These results indicate that the country has the potential for ample utilization of solar energy conversion technologies in most of its territory when considering annual GHI and DNI, suitable terrain availability and energy (electricity and heat) demand from industrial, commercial and residential activities.

Assessment of solar energy resources in Central Asia

The solar energy resources in Central Asia are assessed. Sources of actinometric information—the results of long-term ground-based measurements and mathematical simulation—are analyzed. Actinometric data of the publicly accessible NASA SSE global climate information database for this region is verified and its correspondence to the task was proved. The methods used to assess the gross and technical potential of solar energy are described briefly, and the results of calculations for Uzbekistan and Kyrgyzstan are provided.

Solar energy resource assessment in Chile: Satellite estimation and ground station measurements

The progress from the last four years in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different procedures for the meteorological variables and the effective cloud cover computations that allow estimation of the global horizontal and diffuse irradiation on an hourly basis. Direct normal irradiation is computed by applying proper solar geometry corrections to the direct horizontal irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest solar resources in the world.

Wind and Solar Energy Potential Assessment for Development of Renewables Energies Applications in Bucaramanga, Colombia

Currently, the trend of micro-grids and small-scale renewable generation systems implementation in urban environments requires to have historical and detailed information about the energy potential resource in site. In Colombia, this information is limited and do not favor the design of these applications; for this reason, must be made detailed studies of the energy potential in their cities. In this paper is presented the wind and solar energy resource assessment for the city of Bucaramanga, based on the monitoring on four strategic points during the years 2010, 2011 and 2012. According to the analysis, is evidenced a significant solar resource throughout the year ascending on average to 1 734 kWh/m2, equivalent to 4.8 kWh/m2/day. Also, from a wind statistical study based on the Weibull probability distribution and Wind Power Density (WPD) was established the wind potential as Class 1 according to the scale of the Department of Energy of the United States (DOE), since the average speed is near 1.4 m/s. Due this, it is technically unfeasible the using of micro-turbines in the city, even so their potential for natural ventilation of building was analyzed. Finally, is presented a methodology to analyze solar harvesting by sectors in the city, according to the solar motion and shadowing caused by existing structures.