Optimal design of standalone hybrid renewable energy systems with biochar production in remote rural areas: A case study

For remote agriculture-based rural areas, utilizing the local renewable resources such as biomass, wind, and solar energy could be potentially more efficient than long-distance transmission of electricity. In this paper, a multi-objective optimization model for the design of standalone hybrid renewable energy systems (HRES) in remote rural areas is proposed. The objective is to maximize the profits and the carbon abatement capability of the system by optimal process selection and sizing of HRES components including solar, wind, and biomass generation systems. A case study for the design of an HRES on the Carabao Island in the Philippines is conducted. The result shows a 122 kW solar power plant, a 67 kW onshore wind farm and a 223 kW biomass pyrolysis system constitute the optimal configuration of the hybrid energy system, generating a daily profit of US$ 940. The greenhouse gas emission of the optimal system is -3,339 kg CO2 eq/day, indicating good carbon sequestration performance

Hybrid renewable energy supply for rural healthcare facilities: An approach to quality healthcare delivery

The lack of modern electricity supply has been a major impediment to proper functioning of the healthcare centers in the rural areas, contributing to high maternal and child mortality rates in a country. Therefore, this study focuses on how to address the identified problem so that the healthcare centers or clinics in the remote areas can provide timely delivery of medical services for the concerned people. This paper, then, presents the analysis of stand-alone hybrid renewable energy systems for basic healthcare services in the rural areas, where there is no grid energy supply or the supply from the existing grid is erratic and unreliable. One major factor that informs the selection of the hybrid energy system in this study is that it promises high reliability compared to a single energy system. The research presents a statistical analysis of the potential of wind and solar energies for a selected rural locations in Nigeria based on the available long-term hourly and daily meteorological data. It employs an optimal technical and economic design and sizing of hybrid electrical power systems’ components such as the wind, PV, battery and inverter systems, using the hybrid optimisation software (HOMER). Results show that Sokoto and Jos sites exist in the high wind potential regions, while the remaining sites are only suitable for small wind applications. Values obtained for global radiation show that all the sites enjoy considerable solar energy potential suitable for varying degree of solar energy applications. PV/wind/diesel/battery hybrid system configuration is considered optimum for rural health center at Iseyin, Sokoto, Maiduguri, Jos and Enugu, while hybrid systems involving PV/diesel/battery is considered ideal for Port-Harcourt, due to the quality of renewable energy potential. Hence, it was concluded that, the abundance of wind and solar resources in the country create an ideal environment for inclusion of renewable energy systems in the design and implementation of standalone power supply systems to improve rural healthcare delivery

Energy Production Analysis and Optimization of Mini-Grid in Remote Areas: The Case Study of Habaswein, Kenya

Rural electrification in remote areas of developing countries has several challenges which hinder energy access to the population. For instance, the extension of the national grid to provide electricity in these areas is largely not viable. The Kenyan Government has put a target to achieve universal energy access by the year 2020. To realize this objective, the focus of the program is being shifted to establishing off-grid power stations in rural areas. Among rural areas to be electrified is Habaswein, which is a settlement in Kenya’s northeastern region without connection to the national power grid, and where Kenya Power installed a stand-alone hybrid mini-grid. Based on field observations, power generation data analysis, evaluation of the potential energy resources and simulations, this research intends to evaluate the performance of the Habaswein mini-grid and optimize the existing hybrid generation system to enhance its reliability and reduce the operation costs. The result will be a suggestion of how Kenyan rural areas could be sustainably electrified by using renewable energy based off-grid power stations. It will contribute to bridge the current research gap in this area, and it will be a vital tool to researchers, implementers and the policy makers in energy sector

Integrated optimal design and sensitivity analysis of a stand alone wind turbine system with storage for rural electrification

In this paper, the authors investigate a robust Integrated Optimal Design (IOD) devoted to a passive wind turbine system with electrochemical storage bank: this stand alone system is dedicated to rural electrification. The aim of the IOD is to find the optimal combination and sizing among a set of system components that fulfils system requirements with the lowest system Total Cost of Ownership (TCO). The passive wind system associated with the storage bank interacts with wind speed and load cycles. A set of passive wind turbines spread on a convenient power range (2 – 16 kW) are obtained through an IOD process at the device level detailed in previous papers. The system cost model is based on data sheets for the wind turbines and related to battery cycles for the storage bank. From the range of wind turbines, a “system level” optimization problem is stated and solved using an exhaustive search. The optimization results are finally exposed and discussed through a sensitivity analysis in order to extract the most robust solution versus environmental data variations among a set of good solutions

Techno-Economic Feasibility of a Grid-Connected Hybrid Renewable Energy System for a School in North-West Indonesia

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. open access journalBackground: Schools typically have high diurnal fluctuation in electricity demand, with peak loads during daylight hours, which could be adequately met through harnessing solar renewable resources. This study demonstrates the strength of techno-economic assessment in selection and optimization of a grid-connected hybrid renewable energy system (HRES), utilizing local renewable resources to fulfil the daytime electricity demand for a school in northwest Indonesia. Methods: Three different scenarios are developed for optimizing the HRES configurations, comprising of PV panels, Wind turbine, Battery and Inverter. The following optimization parameters are used—one, technological performance of the HRES, in terms of their energy output to fulfil the energy deficit; two, economic performance of the HRES, in terms of their net present cost (NPC) and payback periods. Results: A clear trade-off is noted between the level of complexity of the three HRES, their renewable electricity generation potentials, NPC and payback periods. Scenario II, comprising of Solar PV and Inverter only, is found to be the most feasible and cost-effective HRES, with the optimized configuration of 245 kW PV capacity and 184 kW inverter having the lowest initial capital cost of US$51,686 and a payback time of 4 years to meet the school’s annual electricity load of 114,654 kWh. Its NPC is US$ −138,017 at the 20th year of installation. The negative value in year 20 is achieved through the sale of 40% of the renewable energy back to the grid. Conclusions: Techno-economic assessment can provide useful decision support in designing HRES relying on solar energy to serve predominantly daytime school electricity requirements in tropical countries

An Economic, Energy, and Environmental Analysis of PV/Micro-CHP Hybrid Systems: A Case Study of a Tertiary Building

Our present standard of living depends strongly on energy sources, with buildings being a primary focus when it comes to reducing energy consumption due to their large contribution, especially in tertiary buildings. The goal of the present study is to evaluate the performance of two different designs of hybrid systems, composed of natural gas engines and photovoltaic panels. This will be done through simulations in TRNSYS, considering a representative office building with various schedules of operation (8, 12, and 24 h), as well as different climates in Spain. The main contributions of this paper are the evaluations of primary energy-consumption, emissions, and economic analyses for each scenario. In addition, a sensitivity analysis is carried out to observe the influence of energy prices, as well as that of the costs of the micro-CHP engines and PV modules. The results show that the scenario with the conventional system and PV modules is the most profitable one currently. However, if electricity prices are increased in the future or natural gas prices are reduced, the scenario with micro-CHP engines and PV modules will become the most profitable option. Energy service engineers, regulators, and manufacturers are the most interested in these results

"WindFi" - a renewable powered base station for rural broadband

The HopScotch rural wireless broadband access test bed uses a network of low power base stations, powered by renewable energy sources to provide a low-cost rural broadband solution. In this paper we discuss the low power design aspects of the HopScotch base station and the impact on the required generation potential of renewable sources, battery bank sizing and the use of tracking PV arrays

Accurate Sizing of Residential Stand-Alone Photovoltaic Systems Considering System Reliability

[EN] In rural areas or in isolated communities in developing countries it is increasingly common to install micro-renewable sources, such as photovoltaic (PV) systems, by residential consumers without access to the utility distribution network. The reliability of the supply provided by these stand-alone generators is a key issue when designing the PV system. The proper system sizing for a minimum level of reliability avoids unacceptable continuity of supply (undersized system) and unnecessary costs (oversized system). This paper presents a method for the accurate sizing of stand-alone photovoltaic (SAPV) residential generation systems for a pre-established reliability level. The proposed method is based on the application of a sequential random Monte Carlo simulation to the system model. Uncertainties of solar radiation, energy demand, and component failures are simultaneously considered. The results of the case study facilitate the sizing of the main energy elements (solar panels and battery) depending on the required level of reliability, taking into account the uncertainties that affect this type of facility. The analysis carried out demonstrates that deterministic designs of SAPV systems based on average demand and radiation values or the average number of consecutive cloudy days can lead to inadequate levels of continuity of supply.This work has been supported by research funds of the Universitat Politecnica de Valencia.Quiles Cucarella, E.; Roldán-Blay, C.; Escrivá-Escrivá, G.; Roldán-Porta, C. (2020). Accurate Sizing of Residential Stand-Alone Photovoltaic Systems Considering System Reliability. Sustainability. 12(3):1-18. https://doi.org/10.3390/su12031274S118123Twaha, S., & Ramli, M. A. M. (2018). A review of optimization approaches for hybrid distributed energy generation systems: Off-grid and grid-connected systems. 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Worldwide LCOEs of decentralized off-grid renewable energy systems

Recent events mean that the security of energy supplies is becoming more uncertain. One way to achieve a more reliable energy supply can be decentralised renewable off-grid energy systems, for which more and more case studies are conducted in research. This review gives a global overview of the costs, in terms of levelised cost of electricity (LCOE), for these autonomous energy systems, which range from $0.03/kWh to about$1.00/kWh worldwide in 2021. The average LCOEs for 100% renewable energy systems have decreased by 9% annually between 2016 and 2021 from $0.54/kWh to$0.29/kWh, presumably due to cost reductions in renewable energy and electricity storage. Our overview can be employed to verify findings on off-grid systems, and to assess where these systems might be deployed and how costs are evolving

Practical Implementation of Hybrid Energy Systems for Small Loads in Rural South Africa

DissertationHybrid renewable energy systems (HRESs), are alternative off-grid methods of generating power to remote rural areas, where power lines are not economically viable. Most of the research studies on renewable hybrid systems or microgrids (MGs) in South Africa, focus mainly on the optimal sizing and optimal control of different systems, by making use of renewable energy simulation softwares, however, there is a lack of research carried out on the implementation of these hybrid systems in real time. The aim is to develop a real time control method for an isolated hybrid system submitted to a variable load, as well as resources. The first step towards achieving this aim, was to critically review available published research works, to describe recent developments in improving the optimum operating concept of microgrid controllers for stand-alone or grid-connected systems. Secondly, to investigate any real-time implementation established by either hierarchical or distributed control. Then to, analyze their reliability and functionality in practical set up of the controller, in managing power in the system to the variable load. The study provided a brief overview of microgrid prototype systems, microgrid controls, operating modes and multi-DER microgrid types built into a hybrid system, which introduces a number of strategies or techniques for managing remote rural application prototypes in an isolated or grid-connected system. However, hierarchical control was found to be more appropriate for large microgrids with multiple types of distributed energy resources (DERs), compared to distributed control, particularly when combined with energy storage systems (ESSs), in isolated mode. The rising of hybrid system controllers in real-time renewable energy for the optimum energy management system (EMS), required the design of a real-time controller to operate the entire system in real time. Increasing popularity of renewable energy (RE) has a control strategy that determined the overall efficiency of the hybrid system (HS), although the energy management system of these systems is particularly complex to be managed. The study's main contribution is to investigate the feasible controller and, later, to present an advanced control strategy for managing and controlling the flow of hybrid renewable energy with a diesel generator (DG) and battery (BT) as a backup in a rural application of SA. EMS would be implemented, using a fuzzy logic controller (FLC) in MATLAB / SIMULINK. This study analysed input and output variables for the design of a controller, with a set of rules and a three-dimension (3D) surface. Simulation results of related studies with different objectives were analysed, with the aim of sussing out an appropriate controller for the current study. Arduino Mega was used for coding and uploaded to the implementation of practical implementation of the study. The system operated successfully by supplying the load. This study finally answered the question of the feasibility of the controller in real-time applications