Techno-economic comparative analysis of renewable energy systems: Case study in Zimbabwe

Fluctuations in fossil fuel prices significantly affect the economies of countries, especially oil-importing countries, hence these countries are thoroughly investigating the increase in the utilization of renewable energy resources as it is abundant and locally available in all the countries despite challenges. Renewable energy systems (RES) such as solar and wind systems offer suitable alternatives for fossil fuels and could ensure the energy security of countries in a feasible way. Zimbabwe is one of the African countries that import a significant portion of its energy needs which endanger the energy security of the country. Several studies in the literature discussed the feasibility of different standalone and hybrid RES either with or without energy storage systems to either maximize the technical feasibility or the economic feasibility; however, none of the studies considered maximizing both feasibilities at the same time. Therefore, we present a techno-economic comparison of standalone wind and solar photovoltaic (PV) in addition to hybrid PV/wind systems based on maximizing the RES fraction with levelized cost of electricity (LCOE) being less than or equal to the local grid tariff where Gwanda, Zimbabwe, is the case study. The methodology suggested in this study could increase the utilization of renewable energy resources feasibly and at the same time increase the energy security of the country by decreasing dependency on imported energy. The results indicate that the PV/wind hybrid system does not only have the best economic benefits represented by the net present value (NPV) and the payback period (PBP), but also the best technical performance; where the maximum feasible size of the hybrid system-2 MW wind and 1 MW PV-has RES fraction of 65.07%, LCOE of 0.1 USD/kWh, PBP of 3.94 years, internal rate of return of 14.04% and NPV of 3.06 × 106 USD. Having similar systems for different cities in Zimbabwe will decrease the energy bill significantly and contribute toward the energy security of the country

100% Renewable Energy Grid for Rural Electrification of Remote Areas: A Case Study in Jordan

Many developing countries suffer from high energy-import dependency and inadequate electrification of rural areas, which aggravates the poverty problem. In this work, Al-Tafilah in Jordan was considered as a case study, where the technical, economic, and environmental benefits of a decentralized hybrid renewable energy system that can match 100% of the city demand were investigated. A tri-hybrid system of wind, solar, and hydropower was integrated with an energy storage system and optimized to maximize the match between the energy demand and production profiles. The optimization aimed at maximizing the renewable energy system (RES) fraction while keeping the levelized cost of electricity (LCOE) equal to the electricity purchase tariff. The techno-economic analysis showed that the optimal system in Al-Tafilah comprises a 28 MW wind system, 75.4 MW PV, and 1 MW hydropower, with a 259 MWh energy storage system, for which a RES fraction of 99% can be achieved, and 47,160 MtCO2 are avoided. This study can be easily extended to other rural cities in Jordan, as they have higher renewable energy system (RES) potential. The presented findings are essential not only for Jordan’s planning and economy-boosting but also for contributing to the ongoing force against climate change

A combined dynamic economic emission dispatch and time of use demand response mathematical modelling framework

In this paper, we integrate a Demand Response (DR) program into the multi-objective dynamic economic emission dispatch (DEED) optimization problem. The resulting optimization problem is termed DR-DEED. The DR program is a time based program known as the Time of Use DR program. The DR program has been developed using the customers’ Price Elasticity Matrices, which models the customer behavior under different conditions. An interactive control strategy between utility and consumers is proposed for the combined DR-DEED model, which determines the optimal power to be generated by minimizing fuel, emissions, and DR costs and also the optimal price. The customer in light of the utility’s optimal price minimizes its electricity cost and optimally schedules power consumption. Obtained results indicate that DR programs are mutually beneficial to utility and consumers alike and can bring about desired demand reduction in the power system.http://scitation.aip.org/content/aip/journal/jrsehb201

Improving Capacity Factor of Transmission Lines by Hybridizing CSP with Wind

Due to intermittent behavior of generated wind power, capacity factor of installed transmission lines decreases, which in return increases the payback time and also limits the grid penetration of the wind power plant. One option to compensate this is by using fossil fuel back up, but it is not a sustainable option due to the increased greenhouse gas emissions associated with fossil fuels. Another option is to couple a concentrated Solar Power (CSP) plant, provided there are ample solar resources available. Additionally, in order to increase the capacity of the combined power plant, storage can be added to the CSP plant. In this paper, detailed modeling of solar resources at Bahce Wind Farm located in the Bahce district of Osmaniye province has been performed and a 50MW CSP plant to hybridize with wind plant has been proposed. Based on the simulation results, it is found that average capacity factor of connected transmission lines can increase by similar to 34%, with approximately 11 % of energy dumped under extreme circumstance

Application of Hubbert Peak Theory to Stimulate Biogas Production

Assessing the amount of fossil fuels remained in the subsurface, specifically oil and gas has been debated extensively since the introduction of Hubbert Peak Theory in 1956. The economic model of Pakistan relies greatly on natural gas. Thus, estimating the volume of natural gas recoverable in the future becomes critical for the development of the country. The main objective of this paper is to examine the applicability of Hubbert Peak Theory in order to determine the ultimate gas recovery under a pessimistic scenario assuming that no further reserves will be discovered in the future. This is useful information because reaching the peak will have implications for Pakistan. Data analysis suggests that Pakistan will most probably peak in natural gas production in 2016 and decline afterwards. Year 2055 is perhaps the point around which the production will approach zero. The results are so alarming that if no major initiative is taken by the government to address the issue then Pakistan's economy will have to face dire consequences. Biogas can serve as a viable alternative to meet the hiking demand of gas, utilizing its own widely available resources. Livestock, bagasse and waste landfills are capable of producing 415.3 million Bcf of biogas annually which if produced today, can substitute 22.5% of the total energy originated from natural gas supplied in the fiscal year 2012-13. The outcomes of this paper might also be applicable to other developing countries having similar resources

Climate and size correction in European Union’s Waste Framework Directive and R1 energy efficiency criteria

This article presents an analysis on the use of the R1 formula to determine the recovery status of some energy from waste plants. Detailed R1 computations are provided to demonstrate the application of R1 guidelines in incineration and gasification facilities. Climate and size correction methods are proposed in consideration of the disadvantage faced by smaller-sized energy from waste plants or those located in warmer regions in meeting the set threshold. A key highlight is the case-based application of climate and size correction factors to three case study plants in scaling the R1 value in consideration of external variants. The proposed size and climate correction factors are compared with the climate correction factor defined in the Waste Framework Directive of the European Union. The application of the proposed correction factors lead to conservative R1 scaling when compared with the application of the Waste Framework Directive climate correction factor. The introduction of the size correction factor addresses an important gap in the current Waste Framework Directive

Sizing renewable energy systems with energy storage systems in microgrids for maximum cost-efficient utilization of renewable energy resources

The hybridization of renewable energy systems (RES) and further integrating them with Energy Storage Systems (ESS) can help improve the RESs’ reliability and reduce the mismatch between energy consumption and generation profiles. The main aim of this study is to suggest a sizing methodology for the RES components with various ESS scenarios in a microgrid through techno-economic feasibility analysis. Although the suggested methodology is flexible to include several RESs and ESSs, the methodology is demonstrated to compare the techno-economic performance of Wind and Photovoltaic (PV) energy systems under four different ESS scenarios; (i) no ESS, (ii) Pumped Hydro Storage (PHS), (iii) Hydrogen Fuel Cell (HFC), and (iv) hybrid ESS (PHS/HFC). The optimal RES configuration is determined by maximizing the RES fraction while equating the Cost of Electricity (COE) to the national utility tariff. However, in the event that there is no feasible system configuration that satisfies the mentioned criteria, the main objective becomes maximizing the RES fraction at the lowest attainable COE. This study outlines that the incorporation of PHS and HFC with the PV/Wind hybrid system increased the demand-supply fraction from 46.5%–89.4% and the RES fraction from 62.6%–91.8% with COE equals to 0.175 USD/kWh