Average Daily Radiation Research Articles

Photovolitaics Concept Integrated on the Grid With the STT-PLN Building

As we enter the 21st century, concerns over dwindling oil and gas reserves have become more pronounced. With energy demand on the rise, particularly in developed nations, projections indicate a 70% increase between 2000 and 2030. By the year 2017, global electricity demand is expected to reach 25.4 trillion kWh. Solar energy emerges as a promising solution, especially in regions like Indonesia, where the entire mainland covers roughly 2 million km2 and receives an average daily radiation distribution of 4.8 kWh/m2. This translates to a solar energy potential of 5.10 mW, equivalent to 112,000 GWp. Technically speaking, solar panels have shown an efficiency improvement of 17.4%. When considering components and the quality absorbed by solar power plants (PLTS) synchronized by KWH EXIM, calculations reveal a performance ratio of 81%, confirming the technical feasibility of implementing such systems

Calibrating the Ångström–Prescott Model with Solar Radiation Data Collected over Long and Short Periods of Time over the Tibetan Plateau

As the coefficients of the Ångström–Prescott model is site-dependent, the sparsity of radiation stations in regions like the Tibetan Plateau (TP) presents challenges for model calibration. Due to the unique climate and the clean air conditions over the TP, it might be feasible to calibrate the Ångström–Prescott model with short-term observations from scientific expeditions. To test this hypothesis, we used various datasets with different lengths at four stations, together with 435 daily radiations measured during a scientific expedition at Banga in the central TP from 2014 to 2015, to calibrate the Ångström–Prescott model. We found that calibration with a 1-year data length resulted in model performances comparable to those with a 20-year data length. Analysis of the expedition observations showed that the monthly average daily radiation ranged from 15.2 MJ/m2d in December 2014 to 26.5 MJ/m2d in July 2015, with an average value of 20.6 MJ/m2d. When this set of expedition data was used for calibration, the Ångström–Prescott model performed well with an NSE (Nash–Sutcliffe efficiency) of 0.820. If no data were available for calibration, the coefficients of the Ångström–Prescott model could also be directly calculated by parameterization methods established with calibrations at the other radiation stations. In this situation, the LiuJD method performed the best with the highest NSE of 0.792, followed by the LiuXY method with an NSE of 0.764. The FAO method performed poorly with an NSE of 0.578, while the Gopinathan method performed the worst with the lowest NSE of 0.218. Thus, the best strategy to calibrate the Ångström–Prescott model in the Tibetan Plateau is to use data from local observations, even if collected over short periods. When these are not available, the coefficients of the Ångström–Prescott model should be calculated using the parameterization method established with calibrations over the Tibetan Plateau.

Analysis The Effect of Solar Radiation on The Efficiency of PV Plant 50 kWp Rooftop UNPAM Viktor

The potential for solar energy in indonesia which is a tropical country is very large with an insolation of around 4.5 Kwh/m2/day. Solar energy in the form of radiation waves will affect the power generated by solar panels and the efficiency of solar panels in generating power. This study was conducted at PV plant pamulang university which has a total of 108 panels with 6 strings and 18 panels in each string. The data in this study were taken per string to see the difference of efficiency in each string. The main problem of this study is to find out how much power and efficiency generated by PV plant against solar radiation. The purpose of this study is to understand and analyze the effect of solar radiation on power and efficiency. The method used is a quantitative descriptive method using a seaward irradiance meter to measure the average daily radiation per string and isolarcloud software to retrieve data from the voltage and current per string. The data taken is then calculated using a formula and then described using tables. Study shows that heat from the weather will result in decreased efficiency and the results of the analysis for a day the average value of radiation is 544.19 w/m2, the average power is 4227.79 watt and the resulting average efficiency is 18.57%.

Türkiye’de İki İlde Optimum Eğim Açılarında Eğimli Yüzeyde Aylık, Mevsimsel, Yıllık Toplam Güneş Işınımının Tahmini

In solar energy systems that use solar panels, it's important to know the best tilt angle to optimize solar energy production. Monthly, seasonal, and annual optimum tilt angles were determined in this study using meteorological insolation data from many years in the provinces of Tekirdag and Konya, which are located in different regions of Turkey. At optimum tilt angles, monthly, seasonal, and annual total radiation on the tilted surface were 1516.7 kWh m-2 year-1, 1504.1 kWh m-2 year-1 and 1448.1 kWh m-2 year-1 in Tekirdag, respectively. In Konya, these values were 1851.4 kWh m-2 year-1, 1833.51 kWh m-2 year-1 and kWh m-2 year-1, respectively. In the seasonal and annual optimum tilt angles, there was an approximately 1% and 5% loss in the total radiation values on the tilted surface, respectively, according to the monthly optimum tilt angle. In addition, the coefficients of the relationship between the monthly mean daily radiation on the tilted surface and the tilt angles were determined for each month using the cubic regression model in both provinces. The Cubic regression model coefficients are computed for each month in the provinces of Tekirdag and Konya. All months in both provinces had R2 (Coefficient of determination) values of 0.999 for the Cubic model. To determine whether there is a difference between the total amounts of radiation reaching the tilted surface for each month at the best tilt angles obtained by the two methods, the t-test was used. The monthly average daily radiation values on the tilted surface obtained by the two methods at the best tilt angles in both provinces have not been found to differ statistically (p>0.05; t=0.001).

Comparative results of the average daily net radiation (Rnd) from meteorological observation data and Landsat–8 remote sensing imagery areas of Hoa Binh province

Comparative results of the average daily net radiation (Rnd) from meteorological observation data and Landsat–8 remote sensing imagery areas of Hoa Binh province

Novel Assessment and Classification of Monthly Average Daily Global Solar Radiation Models Through a Figure of Merit Called Irradiation Time Equivalence: Analysis of 70 Regression Models Based on Air Temperature and Sunshine Hours Predictors

Abstract Irradiation time equivalence pioneers the classification of models that predict monthly average daily global solar radiation on a horizontal surface based on their double cross-validation performances. By exploiting indigenous irradiation data, novel irradiation-based models can be created and used to classify prediction models, thereby facilitating a deeper understanding of model performance beyond routine summary statistics. The concept was demonstrated by formulating novel 1-hour and 2-hour irradiation-based models to predict monthly average daily global horizontal irradiation. Double cross-validations of the two irradiation-based models and 70 existing regression models were performed using a pair of 5-year subsets. The 70 models used the measured meteorological predictors of air temperature and sunshine hours, either alone or combined. The irradiation time equivalence of a model evaluated under double cross-validation has been defined as the minimum number of hours of measured irradiation needed to predict the monthly average daily irradiation in an average year, with a root mean square error less than or equal to that of the model. Despite their intracompetitiveness, all 44 temperature-based models had an irradiation time equivalence of 1 h, while the remaining 26 models that contained the sunshine-hours predictor were classified with a higher-performance rank of 2 h. An irradiation time equivalence scale extending to 13 h was also developed to cater to the classification of higher-performance models. This fresh perspective on model performance directs future investigations toward determining whether prediction models exhibit global classification constancy.

Global solar radiation, assessed using a pyranometer placed on an inclined plane

The city of Zacatecas, due to its geographical location, a city with little industry, neighboring the Tropic of Cancer and a height of the order of 2,492 above sea level, has the conditions for a study of the behavior of solar radiation and its possible potential use to transform it into other types of energy. The objective of this work was to have an irradiance database in the city of Zacatecas using CMP 22 Kipp & Zonen pyranometers from Campbell scientific, in order to satisfy the needs derived from radiation-related industry activities. The pinanometers are located at the Zacatecas_04 Solarimetric Station, which is located on the UAZ Siglo XXL Campus in building 6 of the Academic Unit of Chemical Sciences of the Autonomous University of Zacatecas (Lat: 22°46'21.01''N, Long: 102°38'37.14'') in the city of Zacatecas, Zac, and is part of the Mexican Solarimetric Network promoted by the Mexican Solarimetric Service of the Institute of Geophysics of the National Autonomous University of Mexico. The data was rearranged into hourly, daily and monthly averages. The average daily irradiance was 547 ± 5 W/m².

THE RAINFALL-RUNOFF MODEL FOR THE CARPATHIAN FLYSCH CATCHMENT USING THE SWAT+ HYDROLOGICAL SOFTWARE

Aim of the study: The goal of this study was to apply SWAT+ tools to estimate the water shortage in the Smugawka catchment. Material and methods: The use of the area was documented in the form of an orthophotomap with GIS layers superimposed, which was provided by CORINE Land Cover 2018. A soil and agricultural map, supplemented with lithological content from a detailed geological map, was used as the input layer for QGIS ver. 3.16. In the next stage, multiannual meteorological data (1991–2020) were added to the SWAT+ model, which included: minimum and maximum daily air temperature, daily rainfall, average daily radiation and average daily wind speed. Full integration of the SWAT+ model with QGIS facilitates the procedure of iterative generation and modification of the model input parameters. The calculation of continuous simulations for average long periods of time is presented in the manuscript. Results and conclusions: The application of GIS-based approaches and modeling techniques are crucial in the quest for optimal methods for calculating the water balance today. Our findings also contribute to a better understanding of the hydrological processes at work in the flysch catchment.

Analisis Teknik Serta Kelayakan Ekonomi Pada Perancangan Pembangkit Listrik Tenaga Surya Sistem Hybrid

National electrical energy needs are increasing every year. This is accompanied by an increasingly massive use of fossil energy as a power plant. The government is targeting a share of new and renewable energy (EBT) of at least 23% by 2025. As a tropical country, Indonesia has a large potential for new and renewable energy, which mostly consists of solar energy with an average daily radiation of 4.8 kWh/m2/day. The design of a solar power plant (PLTS) at SMA Negeri 3 Surakarta is an effort to utilize NRE and can be used as a model for environmentally friendly schools for similar public institutions and the general public. This PLTS uses a hybrid system with a generating capacity of 1230 Wp, SCC 60A, 24 V 200 Ah battery and a 2400 W hybrid inverter. Using analysis methods with PVSyst and RetScreen simulations, this PLTS generates electricity of 1,653.2 kWh/year. With an initial investment of IDR 25,186,000, the net present value is IDR 1,210,272 and the payback period is 24 years.

Application of a tungsten apron for occupational radiation exposure in nursing care of children with neuroblastoma during 131I-meta-iodo-benzyl-guanidine therapy

The use of effective shielding materials against radiation is important among medical staff in nuclear medicine. Hence, the current study investigated the shielding effects of a commercially available tungsten apron using gamma ray measuring instruments. Further, the occupational radiation exposure of nurses during 131I-meta-iodo-benzyl-guanidine (131I-MIBG) therapy for children with high-risk neuroblastoma was evaluated. Attachable tungsten shields in commercial tungsten aprons were set on a surface-ray source with 131I, which emit gamma rays. The mean shielding rate value was 0.1 ± 0.006 for 131I. The shielding effects of tungsten and lead aprons were evaluated using a scintillation detector. The shielding effect rates of lead and tungsten aprons against 131I was 6.3% ± 0.3% and 42.1% ± 0.2% at 50 cm; 6.1% ± 0.5% and 43.3% ± 0.3% at 1 m; and 6.4% ± 0.9% and 42.6% ± 0.6% at 2 m, respectively. Next, we assessed the occupational radiation exposure during 131I-MIBG therapy (administration dose: 666 MBq/kg, median age: 4 years). The total occupational radiation exposure dose per patient care per 131I-MIBG therapy session among nurses was 0.12 ± 0.07 mSv. The average daily radiation exposure dose per patient care among nurses was 0.03 ± 0.03 mSv. Tungsten aprons had efficient shielding effects against gamma rays and would be beneficial to reduce radiation exposures per patient care per 131I-MIBG therapy session.

Experimental Analysis of a Photovoltaic Power Plant in a Desert Environment– Adrar area –

Algeria has one of the highest solar deposits in the world, the average duration of sunshine in the Algerian Sahara is 3500 hours, and this potential can be an important factor for sustainable development in this region, if it is exploited economical way. In this context, it should be noted that the city of Adrar is located in the region of the "solar belt", which enjoys abundant sunshine of more than 3000 hours of sunshine per year, based on data from Overall hourly irradiation on a horizontal surface, the Adrar region is distinguished by a higher average daily irradiation of up to 5.7 kWh/m2/day. In the present work, an operational performance analysis of a polycrystalline silicon photovoltaic system for one year is performed. The installed capacity of this system is 20 MW, and it is exposed in an arid climate in Adrar of southern Algeria.

The effect of parameters and irradiance estimation techniques on PV potential quantification: The case of Mexico

The impact of some irradiance estimation techniques and model parameters in the assessment of solar potential has not yet been clarified, therefore, the case of Mexico is used in this work is to reduce such a gap. Firstly, a universe of 1629 weather stations and 108 models were used to study the effect of model-based and interpolation techniques on the estimation of the resource potential. Secondly, a centralized and two decentralized geographic potential scenarios were analyzed. Thirdly, the effect of parameters related to PV solar harvesting and production costs was evaluated. Our results revealed dramatic differences in the resource potential when heuristics models were used; differences up to 10% were found for the same location; in contrast, the evaluated interpolation techniques provided very close results with sensibility indexes (SI) below of 2.11%. Differences up to 15% were found in the average daily irradiance when the available area for PV installation is considered, which revealed the importance of the determination of suitable areas for harvesting. Changes up to %27 in the technical potential were found for different c Si-Poly modules. The parameters affecting most significantly the cost were the annuity factor (SI = 75.89%), the balance of the system (SI = 56.95%) and the PV module investment cost (39.28%). Our results provide reasonable results when compared with actual prices and provide evidence of the role of government policies to lower the costs.

Forecasting the Diffuse Solar Radiation by using a New Modeling over Saudi Arabia

Within the arranging and execution assessment of solar energy projects, particularly within the planning and estimation of solar photovoltaic sources as elective energy sources within the future, exact evaluation of Diffuse Solar Radiation (DSR) is one of the essential and basic issues. The target of this article is to use the new model to predict DSR in four different locations in Saudi Arabia. The author explored the available meteorological and radiation data. The data covers the 25 years from 1990 to 2014 and were measured at Al-Baha, Abha, Jeddah and Taif locations in Saudi Arabia. Through detailed statistical evaluation and analysis, 19 empirical models were tested to construct the best empirical model to estimate the monthly average daily DSR of Saudi Arabia. Using widely used statistical errors, namely MBE, MPE, RMSE, U95, R, t-test and GPI the proposed correlation model was compared with 19 models provided in the literature. Through this analysis, the cubic empirical equation model is selected as the good model. Compared with these existing models, this model reveals accurate results with minimal statistical errors. Based on these results, Model 22 gives the highest GPI value. The conclusion is the cubic equation model of the diffusion fraction (i.e., D/G = 0.215+2.123 (S/So) -3.547(S/So)2+5.142 (S/So)3 is the best agreement model that has been mentioned in the previous discussion. This model is a generalized equation in Saudi Arabia, which can forecast the monthly average daily diffuse radiation on the horizontal plane at any site under similar climatic conditions without the measured climatic conditions. Experts or architects can use this model to perform site selection and technical and financial evaluation of solar energy applications and photovoltaic technology.

Using HOMER for design and economic analysis of a photovoltaic unit integrated with the RO system treating brackish water at a capacity of 3 m3/day

To satisfy the energy demand and environmental protection, solar energy has been widely used and contributed 43% of renewable energy resources. Photovoltaic (PV) is an ideal technology for powering reverse osmosis (RO) desalination units since both PV and RO systems are modular and easily scalable. HOMER sofware can integrate functional tools for designing and sensitivity analysis of hybrid energy systems. Thus, it is useful for finding the least-cost configuration of small-scale PV systems, which can combine with the other energy sources, effectively. This study analyzed a 3kWp PV module installed at a tilt angle of 10.04o, comprising of eleven 280W PV pannels (JA Solar Holding 280JAM6-60-280/SI), one inverter (ABB PVI-3.0-OUTD-S-US-Z-A-240V), three batteries (Trojan SAGM 12-205-12V-205Ah-20h), and the MPPT charge controller. Results showed that the capital cost in the first year was 60.236 million VND and the total project cost for 25 years, accountless of the installation and maintenance cost, was 144.341 million VND. At the average daily radiation of 5.155 kWh/m2/day, the 3kWp PV module could produce 5,145kWh/year and save more than 49,5% of costs for buying grid electricity.

Publicly available UV irradiance data in the contiguous United States and its applications

Background: Skin cancer is the most common type of cancer in the United States. The majority of skin cancer is caused by overexposure to ultraviolet (UV) light. National Environmental Public Health Tracking Program at CDC has collaborated with partners to develop and disseminate county-level daily UV irradiance (2005 to 2015) data for the contiguous United States.Methods: UV dataset was derived based on measurements from the Ozone Monitoring Instrument (OMI) during 2005-2015. UV irradiance data were first calculated at the census tract level; then daily population-weighted UV irradiance were calculated at the county level. We analyzed the spatial distributions and long-term trends of UV irradiance, and ratio of UV irradiance to solar irradiance. We also have used the newly developed dataset in a few applications to improve characterization of UV exposure.Results: The UV dataset is currently the only publicly-available, spatially-resolved, and long-term UV radiation dataset covering the contiguous United States. The national averages across all years available is 2,700 J/m2 for erythemally weighted daily dose of UV irradiance (EDD). UV irradiance increased toward the South and the West. The ratio of UV to solar irradiance mainly increased toward the South and in some areas with high altitude. This spatial variation suggests that using solar irradiance as indicator of UV irradiance in studies covering large geographic regions may bias the true pattern of UV exposure. National annual average daily UV irradiance increased significantly over the years by about 0.5% per year. In addition, we identified hotspots of skin cancer vulnerability, which took into consideration demographic, social risk factors and UV exposure intensity. We also examined state laws allowing sunscreen use in schools in the context of state average UV irradiance. Finally, we are currently studying the association between UV irradiance and cutaneous melanoma incidence rates among white US residents.

Current status of photovoltaic plants in Mexico – An analysis based on online monitoring

Solar inverter providers optionally offer plant operators online access to their installed photovoltaic (PV) systems. Benefits consist of better system monitoring, faster response to maintenance needs, and a more comfortable data acquisition. Data mining from an online database enables a comparative statistical analysis for a large number of plants about specific productivity parameters, emission reductions and monetary savings. Restriction of information usually confines the progress of PV systems. Due to this situation, the Sunnyportal website managed by one of the most important world provider of solar inverters does not delimit the visualization of their own systems. In addition, there is unrestricted access to their available plants in cases where the owners set the status of their plants as “public”. This study gathered and analyzed information on photovoltaic installations in Mexico with free access to production data. The results show an increase of almost 700% in the number of registered plants in Mexico with exponential growth since 2012. Mexico still shows a lack of studies regarding the monitoring of PV systems because available data are scarce. The specific productivity rate of the PV systems primarily depends on solar irradiation on-site, weather conditions, air contamination, the technology employed, correct engineering and plant maintenance. Based on data obtained, conclusions are drawn concerning preferences and performance of Mexican PV plants. The most both surprising as well as important result is that there is no correlation between specific productivity and average daily on-site irradiation.

Cotton production during the tropical monsoon season. I – The influence of variable radiation on boll loss, compensation and yield

Growth and reproductive structure development in cotton (Gossypium hirsutum) is dependent on light intensity, which is often irregular in tropical environments due to shading from cloudiness associated with the monsoon. The objective of this study was to evaluate the effects of cloudiness on reproductive organ abscission and how subsequent compensatory organ replacement, with the provision of irrigation, might recover yield in the semi-arid monsoon tropics. Cotton cultivars representing different morphology were sown in field experiments at closely timed intervals during the early monsoon over five seasons to expose crops to varying amounts of cloud-related shading, creating a matrix of crop responses. A wide range for lint yield (1099 to 2900 kg ha−1) was symptomatic of the treatments’ exposure to highly varied environmental conditions. Lint yield was moderately correlated (P < 0.01; Adj R2 = 0.409) with monsoon cloudiness, reducing 235 kg ha−1 per MJ m−2 decrease in the average daily incident radiation during flowering. Final boll number rather than boll size was the key yield component (P < 0.001), with the number of bolls retained and their location within the canopy correlated with the solar radiation pattern spanning flowering. Boll number m−2 decreased linearly in proportion to mean daily incident solar radiation, by 5.02 and 4.39 bolls MJ m−2 during early (P = 0.007) and late flowering (P = 0.02) respectively. Cloudiness-induced boll loss from the early flowering canopy produced a negative correlation with late boll numbers, increasing by 7.2 bolls per MJ m-2 d−1 decrease in mean incident radiation during early flowering (P < 0.001) as lower canopy boll loss enabled surplus assimilates for later set bolls. Fibre quality parameters were not negatively affected by reduced incident solar radiation during flowering and boll filling.The clustering of sowing times into groups according to similarities in the number and final distribution of bolls within the crop canopy provided a mechanism to identify sowing time treatments that shared similar compensation responses. The highest group yields occurred when minimal cloudiness during flowering allowed uninterrupted boll accumulation or alternatively when moderate boll losses from the lower canopy were compensated via additional later set bolls when radiation improved. Yield recovery was restricted for groups where cloudiness was ongoing or increased during late flowering or when canopy factors detracted from efficient use of available radiation. Extrapolation of the linear relationship between boll number and incident radiation showed boll retention was maximised at a mean daily value of 24.2 MJ m−2 (Rmax). Quantification of Rmax was a key finding as it could be applied to calculate a cumulative radiation deficit (RD) = ∑ (if daily radiation is < Rmax then daily RD = Rmax-daily radiation) and provided an alternative independent variable for quantifying the impact of cloudiness during flowering on boll survival. Wider application of this concept requires research in larger solar radiation and temperature regimes than observed here.Yield compensation from cloud induced fruit abscission in the semi-arid tropics will be assisted by management that can extend flowering to create new fruiting sites whilst balancing the partitioning of canopy growth.

Exploration of Climate Change Effects on Shifting Potato Seasons, Yields and Water Use Employing NASA and National Long-Term Weather Data

Climate change is a threat to agriculture but also presents opportunities and requires adaptation strategies. In many countries adequate meteorological data is lacking, so this is where NASA weather data are of assistance. We aimed to develop a generic and easily applicable approach to calculate the effect of climate change on potato yields and water need. We therefore used the NASA-Langley-Gaisma weather database which has data of thousands of sites worldwide. Comparing these with national data of a particular country, Turkey in this case showed that they compare well but diverge somewhat at the lower temperature range. The evapotranspiration (ETP) rate was not supplied by NASA, so we estimated this rate by multiplying the average daily radiation in MJ/m2 by 5. There was a good correlation with actual ETP, and where there is a systematic deviation, it will not change conclusions when comparing sites and climate change scenarios. Next, it was assumed that potato crops are planted in spring when the average daily temperature is above 13 °C. When the average daily temperature reaches 22 °C and above, it is assumed that the crop is harvested as it gets too hot. For the highland sites with summer crops, this gave planting and harvest dates that reflect reality, but for the coastal sites, the time window with this method was too short. Since there is no risk of frost, farmers plant at lower temperatures, in local niches not covered by the regional met stations. The effect of climate change, higher temperatures, shifting planting dates and a CO2 induced increased growth rate on yield and water need of the crops was well explored with the LINTUL crop growth model. At unchanged rates of incident solar radiation and unchanged planting dates, an average decrease in potential yield from 94 to 83 t/ha is calculated. Extention of summer by 20 days on average causes decrease in the frost-free period, which leads to an overall increase of potential yield of the highland summer crops by 3%. The length of the growing season of the coastal spring crops is not extended; the season just moves closer to the winter with shorter day lengths and less radiation. So here yields are not affected by adverse high temperatures but are reduced by lower radiation levels. For both highland summer and coastal spring crops, an increase in the CO2 concentration of the atmosphere from the current 415 to future level of around 550 ppm is expected to increase the radiation use efficiency, so also yields by 25%.

RANCANG BANGUN PEMBANGKIT LISTRIK TENAGA SURYA (PLTS) ON GRID DI ECOPARK ANCOL

Indonesia is a tropical area that has a very large amount of sunlight which is a potential renewable energy with an average daily irradiation of 4.5 - 4.8 kWh / m2.As a renewable energy, sunlight is not pollutant, will not run out, but is free or free.Therefore this energy source can be utilized for electricity through the Solar Power Plant (PLTS) system. This research will discuss the design of On Grid Solar Power Generation (PLTS) systems by generating 60% of the load capacity in the Learning Farm area.The power generated is 68.17 kWp using 100 solar cell modules. This PLTSis designed to reduce electricity consumption from PLN in Ancol Ecopark.This location is considered to have good solar radiation potential and a largeavailability of land. The results of this design are expected to be a referencefor the Ancol ecopark learning farm in order to obtain a good match between energy needs, price, and quality.ABSTRAK:Indonesia merupakan daerah tropis yang mempunyai sinar matahari yang sangat besar menjadi potensi energi terbarukan dengan iradiasi harian rata-rata 4,5 – 4,8 kWh/m2. Sebagai energi terbarukan, sinar matahari tidak bersifat polutif, tidak akan habis, namun bersifat gratis atau cuma-cuma. Maka dari itu sumber energi ini dapat dimanfaatkan untuk kelistrikan melalui sistem Pembangkit Listrik Tenaga Surya (PLTS). Pada penelitian ini akan dibahas perancangan sistem Pembangkit Listrik Tenaga Surya (PLTS) On Grid dengan membangkitkan 60 % dari kapasitas beban di area Learning Farm. Besar daya yang dibangkitkan sebesar 68,17 kWp dengan menggunakan 100 modul sel surya. PLTS ini dirancang untuk mengurangi pemakaian listrik dari PLN di Ecopark Ancol. Lokasi ini dinilai memiliki potensi radiasi matahari yang cukup baik dan ketersediaan lahan yang luas. Hasil dari perancangan ini diharapkan menjadi acuan bagi pihak ecopark learning farm Ancol agar diperoleh kesesuaian antara kebutuhan energi, harga, dan kualitas yang baik

Assessment and Day-Ahead Forecasting of Hourly Solar Radiation in Medellín, Colombia

The description and forecasting of hourly solar resource is fundamental for the operation of solar energy systems in the electric grid. In this work, we provide insights regarding the hourly variation of the global horizontal irradiance in Medellín, Colombia, a large urban area within the tropical Andes. We propose a model based on Markov chains for forecasting the hourly solar irradiance for one day ahead. The Markov model was compared against estimates produced by different configurations of the weather research forecasting model (WRF). Our assessment showed that for the period considered, the average availability of the solar resource was of 5 PSH (peak sun hours), corresponding to an average daily radiation of ~5 kWh/m2. This shows that Medellín, Colombia, has a substantial availability of the solar resource that can be a complementary source of energy during the dry season periods. In the case of the Markov model, the estimates exhibited typical root mean squared errors between ~80 W/m2 and ~170 W/m2 (~50%–~110%) under overcast conditions, and ~57 W/m2 to ~171 W/m2 (~16%–~38%) for clear sky conditions. In general, the proposed model had a performance comparable with the WRF model, while presenting a computationally inexpensive alternative to forecast hourly solar radiation one day in advance. The Markov model is presented as an alternative to estimate time series that can be used in energy markets by agents and power-system operators to deal with the uncertainty of solar power plants.