scholarly journals Enhancement of Cloudless Skies Frequency over a Large Tropical Reservoir in Brazil

2020 ◽  
Vol 12 (17) ◽  
pp. 2793 ◽  
Author(s):  
André R. Gonçalves ◽  
Arcilan T. Assireu ◽  
Fernando R. Martins ◽  
Madeleine S. G. Casagrande ◽  
Enrique V. Mattos ◽  
...  

Several studies show the effects of lake breezes on cloudiness over natural lakes and large rivers, but only few contain information regarding large flooded areas of hydroelectric dams. Most Brazilian hydropower plants have large water reservoirs that may induce significant changes in the local environment. In this work, we describe the prevailing breeze mechanism in a Brazilian tropical hydropower reservoir to assess its impacts on local cloudiness and incoming surface solar irradiation. GOES-16 visible imagery, ISCCP database products, and ground measurement sites operated by INMET and LABREN/INPE provided data for the statistical analysis. We evaluate the cloudiness frequency assuming two distinct perspectives: spatial distribution by comparing cloudiness over the water surface and areas nearby its shores, and time analysis by comparing cloudiness prior and after reservoir completion. We also evaluated the solar irradiance enhancement over the water surface compared to the border and land areas surrounding the hydropower reservoir. The results pointed out daily average cloudiness increases moving away from the reservoir in any of the four cardinal directions. When looking at the afternoon-only cloudiness (14 h to 16 h local time), 4% fewer clouds were observed over the flooded area during summer (DJF). This difference reaches 8% during autumn (MAM) and spring (SON). Consequently, the irradiance enhancement at the water surface compared to external areas was around 1.75% for daily average and 4.59% for the afternoon-only average. Our results suggest that floating solar PV power plants in hydropower reservoirs can be an excellent option to integrate both renewable energy resources into a hybrid power generation due to the high solar irradiance in Brazilian territory combined with the prevailing breeze mechanism in large tropical water reservoirs.

2019 ◽  
Vol 122 ◽  
pp. 02004 ◽  
Author(s):  
Javier Menéndez ◽  
Jorge Loredo

In 2017, electricity generation from renewable sources contributed more than one quarter (30.7%) to total EU-28 gross electricity consumption. Wind power is for the first time the most important source, followed closely by hydro power. The growth in electricity from photovoltaic energy has been dramatic, rising from just 3.8 TWh in 2007, reaching a level of 119.5 TWh in 2017. Over this period, the contribution of photovoltaic energy to all electricity generated in the EU-28 from renewable energy sources increased from 0.7% to 12.3%. During this period the investment cost of a photovoltaic power plant has decreased considerably. Fundamentally, the cost of solar panels and inverters has decreased by more than 50%. The solar photovoltaic energy potential depends on two parameters: global solar irradiation and photovoltaic panel efficiency. The average solar irradiation in Spain is 1,600 kWh m-2. This paper analyzes the economic feasibility of developing large scale solar photovoltaic power plants in Spain. Equivalent hours between 800-1,800 h year-1 and output power between 100-400 MW have been considered. The profitability analysis has been carried out considering different prices of the electricity produced in the daily market (50-60 € MWh-1). Net Present Value (NPV) and Internal Rate of Return (IRR) were estimated for all scenarios analyzed. A solar PV power plant with 400 MW of power and 1,800 h year-1, reaches a NPV of 196 M€ and the IRR is 11.01%.


2019 ◽  
Vol 25 (10) ◽  
pp. 1-19
Author(s):  
Mena Safaa Mohammed ◽  
Emad Talib Hashim

Solar photovoltaic (PV) system has emerged as one of the most promising technology to generate clean energy. In this work, the performance of monocrystalline silicon photovoltaic module is studied through observing the effect of necessary parameters: solar irradiation and ambient temperature. The single diode model with series resistors is selected to find the characterization of current-voltage (I-V) and power-voltage (P-V) curves by determining the values of five parameters ( ). This model shows a high accuracy in modeling the solar PV module under various weather conditions. The modeling is simulated via using MATLAB/Simulink software. The performance of the selected solar PV module is tested experimentally for different weather data (solar irradiance and ambient temperature) that is gathered from October 2017 to April 2018 in the city of Baghdad. The collected data is recorded for the entire months during the time which is limited between 8:00 AM and 1:00 PM. This work demonstrates that the change in a cell temperature is directly proportional with the PV module current, while it is inversely proportional with the PV module voltage. Additionally, the output power of a PV module increases with decreasing the solar module temperature. Furthermore, the Simulink block diagram is used to evaluate the influence of weather factors on the PV module temperature by connecting to the MATLAB code. The best value from the results of this work was in March when the solar irradiance was equal to 1000 W/m2 and the results were: Isc,exp=3.015, Isc,mod=3.25 , RE=7.79 and Voc,exp=19.67 ,Voc,mod=19.9 ,RE=1.1


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4935
Author(s):  
B. Koti Reddy ◽  
Amit Kumar Singh

The World Energy Council, in its 2019 World Energy Scenarios Report, advised policymakers to identify innovative opportunities for the integration of renewable energy resources into existing electrical power systems to achieve a fast and affordable solution. However, large-scale industries with cogeneration units are facing problems in handling the higher penetration levels of intermittent renewable energies. This paper addresses large-size photovoltaic power integration problems and their optimal operation. This work considers the case of a chemical industry having both cogeneration power and solar photovoltaics. Here, a modified firefly algorithm and a hybrid power resource optimization solver are proposed. The results of the proposed method are compared with other benchmark techniques, to confirm its advantages. The proposed techniques can be used in industries having cogeneration power plants with photovoltaics for better optimization and to meet the guidelines specified in IEEE 1547. The voltage ramp index is proposed to determine the voltage ramp up and down with intermittent solar irradiance. Additionally, a machine learning technique is used to predict the cogeneration plant efficiency at different loads and the solar irradiance under varying weather conditions. Finally, this paper proposes the effectiveness of the modified heuristic technique and certain guidelines, including solvers for industrial use.


Author(s):  
Anuj Gupta ◽  
Kapil Gupta ◽  
Sumit Saroha

Renewable energy has received a lot of attention in the previous two decades when it comes to meeting electrical needs in the home, industrial, and agricultural sectors. Solar forecasting is critical for the efficient operation, scheduling, and balancing of energy generation by standalone and grid-connected solar PV systems. A variety of models and methods have been developed in the literature to forecast solar irradiance. This paper provides an analysis of the techniques used in the literature to forecast solar irradiance. The main focus of the study is to investigate the influence of meteorological variables, time horizons, climatic zone, pre-processing technique, optimization & sample size on the complexity and accuracy of the model. Due to their nonlinear complicated problem solving skills, artificial neural network based models outperform other models in the literature. Hybridizing the two models or performing pre-processing on the input data can improve their accuracy even more. It also addresses the various main constituents that influence a model’s accuracy. The paper provides key findings based on studied literature to select the optimal model for a specific site. This paper also discusses the metrics used to measure the efficiency of forecasted model. It has been observed that the proper selection of training and testing period also enhance the accuracy of the model.


2021 ◽  
Vol 13 (6) ◽  
pp. 3349
Author(s):  
Riaz Uddin ◽  
Abdurrahman Javid Shaikh ◽  
Hashim Raza Khan ◽  
Muhammad Ayaz Shirazi ◽  
Athar Rashid ◽  
...  

To a great extent, Pakistan and Turkey rely on imported fossil fuels to meet their energy demands. Pakistan is moving in the right direction, placing focus on renewable energy resources in its current infrastructure in order to address the energy shortage. Several projects (e.g., wind power and solar PV (photovoltaic) technologies) are operational or under development; they are intended to reduce energy challenges in Pakistan. The new government in Pakistan aims to increase the share of renewable energy in total power generation to 30% by 2030. On the other hand, Turkey surpasses Pakistan in renewable energy resources; for example, there are 186 operational wind energy power plants across the country. In addition, Turkey utilizes solar energy—mainly for residential usage. Turkey’s Vision 2023 energy agenda aims to supply 30% of their power demands from modern renewable energy resources. Turkey has implemented solar PV, solar buildings, wind power plants, geothermal energy resources, and biomass technology for heating, cooling and electricity generation. At present, Turkey’s supply to meet energy demands in the country is 56% fossil fuel energy resources and 44% renewable energy, including hydropower. Accessible details reveal that geothermal energy resources have been continuously neglected in Pakistan by the Ministry of Energy (power division); this is in contrast to the Turkish case, in which utilization of geothermal energy resources for heating and cooling purposes is efficient. With all the facts and figures under consideration, in this paper, comparative analyses are performed which reveal that the production of electricity from geothermal energy technologies is lower than the massive potential in both countries. Recommendations are made for important policies to promote renewable energy technologies, which could effectively support energy decentralization by providing electricity to rural areas and the national grid.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Siti Fatihah Salleh ◽  
Mohd Eqwan Mohd Roslan ◽  
Adlansyah Abd Rahman ◽  
Abdul Halim Shamsuddin ◽  
Tuan Ab Rashid Tuan Abdullah ◽  
...  

Abstract Background The global commitment to climate change mitigation enforces the worldwide development of renewable energy sources. Therefore, various studies have investigated the growth of renewable energy in Malaysia, most commonly based on biogas and hydropower. In this article, the dynamics of Malaysia’s renewable energy development is critically examined by using the latest official national reports and other reliable resources. Results The study reveals the influencing factors that shape renewable energy growth in a developing country endowed with substantial biomass resources, such as Malaysia. Likewise, it evaluates the evolution of renewable energy in the electricity sector. In 2017, renewable energy represented about 3.5% of the Malaysian electricity generation mix with 1122 MW of installed capacity. A closer look into the renewable energy resources, i.e. biomass, biogas, solar and small hydro power, revealed that over 47% of the grid-connected power generation came from solar photovoltaic (PV) energy. While solar PV capacity continues to accelerate, the development of other renewable resources, especially biomass, is seeing growth at a significantly slower pace. This article investigates the underlying causes of the skewed development rate as well as the potential strategies that may be adopted to promote a diversification of renewable energy resources. In light of this, introduction of a new national bioenergy policy is proposed, through which four essential programmes could be implemented: (i) enhanced bioenergy conversion efficiency and waste management, (ii) biomass co-firing in coal power plants, (iii) conversion of biogas to biomethane and bio-compressed natural gas (bio-CNG), (iv) large-scale biomass power plants. A total of 4487 MW of additional power could be connected to the grid upon successful implementation of a large-scale biomass power plant programme. Conclusions The establishment of a comprehensive and inclusive national bioenergy policy will lead towards a sustainable future of renewable energy development in Malaysia.


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7494
Author(s):  
Mohammed W. Baidas ◽  
Rola W. Hasaneya ◽  
Rashad M. Kamel ◽  
Sultan Sh. Alanzi

With the rapidly evolving mobile technologies, the number of cellular base stations (BSs) has significantly increased to meet the explosive demand for mobile services and applications. In turn, this has significantly increased the capital and operational expenses, due to the increased electricity prices and energy consumption. To generate electricity, power plants mainly rely on fossil fuels, which are non-renewable energy resources. As a result, CO2 emissions also increase, which adversely affect health and environment. For wireless access technologies and cellular networks, BSs are the largest power consumer, and the network energy consumption is mainly dominated by the network infrastructure, which makes the telecommunications sector liable for energy consumption as well as CO2 emissions around the globe. Alternatively, solar energy is considered as an eco-friendly and economically attractive solution, due to its cost-effectiveness and sustainability. In this paper, the potentials of photovoltaic (PV) solar power to energize cellular BSs in Kuwait are studied, with the focus on the design, implementation, and analysis of off-grid solar PV systems. Specifically, system components, such as the number of PV panels, batteries, and converters needed for the design are determined and evaluated via HOMER software, with the focus on minimizing the net present cost (NPC). A comparison between various PV, diesel generator (DG), and battery bank (BB) system configurations is also performed. Moreover, a comparison of system deployment area will be presented for different PV panels that have different output power and panel sizes, in addition to utilizing a solar tracking system. It is revealed that utilizing a hybrid system configuration (i.e., PV-DG-BB) decreases fuel consumption per year by almost 95% in comparison to the conventional DG-only based electric systems. Not only that, but utilizing a pure off-grid solar PV system (i.e., PV-BB) can significantly reduce the total NPC while completely eliminating CO2 emissions; however, at the expense of more land.


2018 ◽  
Vol 10 (10) ◽  
pp. 3690 ◽  
Author(s):  
Yahya Alharthi ◽  
Mahbube Siddiki ◽  
Ghulam Chaudhry

The economic growth and demographic progression in Saudi Arabia increased spending on the development of conventional power plants to meet the national energy demand. The conventional generation and continued use of fossil fuels as the main source of electricity will raise the operational environmental impact of electricity generation. Therefore, using different renewable energy sources might be a solution to this issue. In this study, a grid-connected solar PV-wind hybrid energy system has been designed considering an average community load demand of 15,000 kWh/day and a peak load of 2395 kW. HOMER software is used to assess the potential of renewable energy resources and perform the technical and economic analyses of the grid-connected hybrid system. The meteorological data was collected from the Renewable Resources Atlas developed by the King Abdullah City of Atomic and Renewable Energy (KACARE). Four different cities in the Kingdom of Saudi Arabia, namely, the cities of Riyadh, Hafar Albatin, Sharurah, and Yanbu were selected to do the analyses. The simulation results show that the proposed system is economically and environmentally feasible at Yanbu city. The system at this city has the lowest net present cost (NPC) and levelized the cost of energy (LCOE), highest total energy that can be sold to the grid, as well as the lowest CO2 emissions due to a highly renewable energy penetration. This grid-connected hybrid system with the proposed configuration is applicable for similar meteorological and environmental conditions in the region, and around the world. Reduction of some greenhouse gasses as well as the reduction of energy costs are main contributors of this research.


2021 ◽  
Vol 13 (6) ◽  
pp. 3364
Author(s):  
Amr Zeedan ◽  
Abdulaziz Barakeh ◽  
Khaled Al-Fakhroo ◽  
Farid Touati ◽  
Antonio S. P. Gonzales

Soiling losses of photovoltaic (PV) panels due to dust lead to a significant decrease in solar energy yield and result in economic losses; this hence poses critical challenges to the viability of PV in smart grid systems. In this paper, these losses are quantified under Qatar’s harsh environment. This quantification is based on experimental data from long-term measurements of various climatic parameters and the output power of PV panels located in Qatar University’s Solar facility in Doha, Qatar, using a customized measurement and monitoring setup. A data processing algorithm was deliberately developed and applied, which aimed to correlate output power to ambient dust density in the vicinity of PV panels. It was found that, without cleaning, soiling reduced the output power by 43% after six months of exposure to an average ambient dust density of 0.7 mg/m3. The power and economic loss that would result from this power reduction for Qatar’s ongoing solar PV projects has also been estimated. For example, for the Al-Kharasaah project power plant, similar soiling loss would result in about a 10% power decrease after six months for typical ranges of dust density in Qatar’s environment; this, in turn, would result in an 11,000 QAR/h financial loss. This would pose a pressing need to mitigate soiling effects in PV power plants.


2021 ◽  
Vol 13 (7) ◽  
pp. 3933
Author(s):  
Solomon E. Uhunamure ◽  
Karabo Shale

South Africa is been faced with erratic power supply, resulting in persistent load shedding due to ageing in most of its coal-fired power plants. Associated with generating electricity from fossil fuel are environmental consequences such as greenhouse emissions and climate change. On the other hand, the country is endowed with abundant renewable energy resources that can potentially ameliorate its energy needs. This article explores the viability of renewable energy using the strengths, weaknesses, opportunities and threats (SWOT) analysis approach on the key renewable potential in the country. The result indicates that geographic position, political and economic stability and policy implementation are some of the strengths. However, Government bureaucratic processes, level of awareness and high investment cost are some of the weaknesses. Several opportunities favour switching to renewable energy, and these include regional integration, global awareness on climate change and the continuous electricity demand. Some threats hindering the renewable energy sector in the country include land ownership, corruption and erratic climatic conditions. Some policy implications are suggested based on the findings of the study.


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