scholarly journals Comparative Analysis of Reliable, Feasible, and Low-Cost Photovoltaic Microgrid for a Residential Load in Rwanda

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Cyprien Nsengimana ◽  
Xin Tong Han ◽  
Ling-ling Li

Photovoltaic microgrids provide free renewable energy solutions for Rwandans. Although solar technology keeps on its advancement, hydropower remains the principal power source in Rwanda. Other renewable power sources include wind and geothermal energies that are not yet fully exploited. Nonrenewable sources in Rwanda including methane, peat, thermal, and fuels are also used for providing energy solutions for the citizens. Rwanda Energy Group (REG) sets the energy strategic plan since 2015 for achieving the minimum of 512 MW of energy production in 2024/2025 to meet the total energy demand. The plan predicted 52% for grid-connected and 48% for off-grid (standalone) connections. The literature survey and data analysis collected on site were used to evaluate and determine the best cheaper microgrid model from the three comparison case studies for the household in Rwanda. The study focused on the economic power generation model mainly based on solar resources to minimize the electricity cost and provide income for the excess energy produced. Moreover, the study resulted in a low-cost (four times cheaper), reliable, and affordable grid-connected PV and battery microgrid model for a residential home with a minimum daily load of 5.467 kWh. The simulation results based on economic comparison analysis found the levelized cost of energy (LCOE) and net present cost (NPC) for each power-generated model by using Hybrid Optimization Model for Electric Renewable (Homer) pro software. The results show that the LCOE for electricity production by each of the Grid connected-PV-Battery system, Diesel GenSet-PV-Batteries, and PV-Batteries systems was 0.0645 US$/1 kWh, 1.38 US$/1 kWh and 1.82 US$/1 kWh, respectively, compared with 0.2621 US$/1 kWh, the current residential electricity price (2020) for Rwanda.

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3260
Author(s):  
Xiaowen Zhan ◽  
Minyuan M. Li ◽  
J. Mark Weller ◽  
Vincent L. Sprenkle ◽  
Guosheng Li

Transitioning from fossil fuels to renewable energy sources is a critical goal to address greenhouse gas emissions and climate change. Major improvements have made wind and solar power increasingly cost-competitive with fossil fuels. However, the inherent intermittency of renewable power sources motivates pairing these resources with energy storage. Electrochemical energy storage in batteries is widely used in many fields and increasingly for grid-level storage, but current battery technologies still fall short of performance, safety, and cost. This review focuses on sodium metal halide (Na-MH) batteries, such as the well-known Na-NiCl2 battery, as a promising solution to safe and economical grid-level energy storage. Important features of conventional Na-MH batteries are discussed, and recent literature on the development of intermediate-temperature, low-cost cathodes for Na-MH batteries is highlighted. By employing lower cost metal halides (e.g., FeCl2, and ZnCl2, etc.) in the cathode and operating at lower temperatures (e.g., 190 °C vs. 280 °C), new Na-MH batteries have the potential to offer comparable performance at much lower overall costs, providing an exciting alternative technology to enable widespread adoption of renewables-plus-storage for the grid.


2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Oying Doso ◽  
Sarsing Gao

Abstract Technological advancement is specifically identified by the usage of energy. The energy requirement is increasing because of the exponential population rise, increased industrial activities, and subsequent accelerated economic activities in both urban and suburban areas. The traditional power sources are becoming unsustainable as energy demand and induction of new sources for augmenting the energy need are lopsided. Additionally, traditional energy sources cause pollution, natural hazards, and more importantly, it is uneconomical. Due to these reasons, it becomes compelling to look for alternative sources of energy. Hydropower generation is reliable, non-polluting to a large extent, and a cheaper source of electrical energy. However, the conventional large hydropower projects, especially with reservoir components, are being opposed worldwide for social, environmental, economic, and safety reasons. Therefore, electricity production from free-flowing water may present a viable choice. Here, the free-flowing river water current is used to drive vertical-axis turbines preferably, Savonius rotors which are ideally built for wind energy conversion systems (WECS). The rotor is directly coupled to electric generators, and the scheme presents a typical variable voltage and variable frequency system similar to that of WECS except that the working force is due to water rather than wind. The use of the Savonius rotor for hydrokinetic power generation is uncommon; however, increased exploitation of this methodology may help in augmenting future energy need. This paper reviews the Savonius rotor and its possible application for hydrokinetic power generation; the merits and demerits of such schemes are clearly outlined.


Author(s):  
Junzo Watada ◽  
Haydee Rocio Melo ◽  
Jaeseok Choi

Recently, renewable power sources such as WTG and PV have become viable economic options for generating sustainable energy. However, WTG and PV have an inconstant power production problem. To solve this problem, multi-state models have been proposed. The electricity generated from these units varies with different time scales: hourly, daily and seasonally. Since planning an optimal size generates cost losses to the customer, three models should be built: a load model, generation model, and service cost model. Loss of energy expectation (LOEE) and loss of load expected (LOLE) are calculated for the load and generation model. The reliability value is calculated to determine the number of required renewable generators. As a result, the system is constructed to have sufficient capacity, and the utility cost became the main objective of the total service costs.


Author(s):  
Marianne Salomón ◽  
María F. Gómez ◽  
James Spelling ◽  
Andrew Martin

Biomass-based fuels have attracted worldwide interest due to their plentiful supply and their environmentally friendly characteristics. In many cases they are still considered waste but for most industries in Sweden, biomass has changed from being simply a disposal problem to become an important part of the energy supply, thanks to the long-term efforts made by the government, researchers and industry, where energy policies have played an important role. However, the amount of power that could be generated from biomass resources is much greater than that which is currently used. To effectively capture this resource requires a new generation of biomass power plants and their effective integration into already existing industrial processes. The implementation of an integrated polygeneration scheme requires the simultaneous consideration of technical, economic and environmental factors to find optimum solutions. With this in mind, a unified modeling approach that takes into account thermodynamic as well as economic and environmental aspects was used. The analysis was done using ASPEN Utilities and the MATLAB optimization toolbox. A specific case of a sawmill in Sweden, with an annual capacity of 130’000 m3 of sawn wood, has been analyzed and different options for generating electricity and process heat (for the sawmill and for a district heating network) as well as densified biofuels was analyzed. Optimization was then applied for different configurations and operational parameters. The results show that the sawmill has the capability to not only supply its own energy needs, but also to export from 0.4 to 1MW of electricity to the grid, contribute 5 to 6 MWth of district heating and 20 000 ton/y of biomass pellets. The production of pellets helps to maintain the electricity production throughout the year when the district heating demand is lower. However, the levelized electricity cost is higher than the usual electricity price in the Nordic electricity market and may have difficulty to competing with low-cost electricity sources, such as nuclear energy and hydropower. In spite of this, polygeneration remains attractive for covering the energy demands of the sawmill and pelletization plant.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 357
Author(s):  
Pedro Moura ◽  
José Ignacio Moreno ◽  
Gregorio López López ◽  
Manuel Alvarez-Campana

University campuses are normally constituted of large buildings responsible for high energy demand, and are also important as demonstration sites for new technologies and systems. This paper presents the results of achieving energy sustainability in a testbed composed of a set of four buildings that constitute the Telecommunications Engineering School of the Universidad Politécnica de Madrid. In the paper, after characterizing the consumption of university buildings for a complete year, different options to achieve more sustainable use of energy are presented, considering the integration of renewable generation sources, namely photovoltaic generation, and monitoring and controlling electricity demand. To ensure the implementation of the desired monitoring and control, an internet of things (IoT) platform based on wireless sensor network (WSN) infrastructure was designed and installed. Such a platform supports a smart system to control the heating, ventilation, and air conditioning (HVAC) and lighting systems in buildings. Furthermore, the paper presents the developed IoT-based platform, as well as the implemented services. As a result, the paper illustrates how providing old existing buildings with the appropriate technology can contribute to the objective of transforming such buildings into nearly zero-energy buildings (nZEB) at a low cost.


2020 ◽  
Vol 13 (1) ◽  
pp. 93
Author(s):  
Wesam H. Beitelmal ◽  
Paul C. Okonkwo ◽  
Fadhil Al Housni ◽  
Wael Alruqi ◽  
Omar Alruwaythi

Diesel generators are being used as a source of electricity in different parts of the world. Because of the significant expense in diesels cost and the requirement for a greener domain, such electric generating systems appear not to be efficient and environmentally friendly and should be tended to. This paper explores the attainability of utilizing a sustainable power source based on a cross-breed electric system in the cement factory in Salalah, Oman. The HOMER software that breaks down the system setup was utilized to examine the application and functional limitations of each hybridized plan. The result showed that a renewable-energy (RE)-based system has a lower cost of energy (COE) and net present cost (NPC) compared to diesel generator-based hybrid electric and standalone systems. Although the two pure renewable hybrid energy systems considered in this study displayed evidence of no emissions, lower NPC and COE values are observed in the photovoltaic/battery (PV/B) hybrid energy system compared with photovoltaic/wind turbine/battery (PV/WT/B). The PV/WT/B and PV/B systems have higher electricity production and low NPC and COE values. Moreover, the PV/B has the highest return on investment (ROI) and internal rate of return (IRR), making the system the most economically viable and adjudged to be a better candidate for rural community electrification demands.


2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Shakib Hassan Eon ◽  
Shakib Hassan Eon ◽  
Shakib Hassan Eon

Renewable energy generation is no more an alternative rather it becomes a choice for the power generation to meet the upcoming energy demand. Considering the non- renewable energy unavailability, as well as, the environmental impact, renewable energy should be the first choice. Most of the power generation in Bangladesh comes from nonrenewable energy and a noticeable amount of energy is imported from abroad. As a developing country, it is not cost-efficient and never ensures energy security. To ensure long-term energy security, it is time to shift power generation from nonrenewable to renewable energy generation. This paper presents an approximate calculation for the renewable power generating plant cost and returning year. The cost calculation is done in the context of Bangladesh.


Author(s):  
Iván Andrade ◽  
Rubén Peña ◽  
Ramón Blasco-Gimenez ◽  
Javier Riedemann ◽  
Cristian Pesce

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