ABSTRACT
The Covid-19 pandemic is exerting a significant influence on global energy markets, and continuing to hinder the growth of core technology for the implementation of renewable forms of energy. With an unprecedented effect, the new coronavirus, known as SARS-CoV2, has succeeded to seize the control of most cities of the world and led to their closure. The newly-emerged virus has also resulted in environmental changes. The present study was conducted to show the indirect positive effects of COVID-19 on the reduction of air pollution, particularly in countries such as Italy, France, and India. Our research proved the existence of meaningful relationships between probable actions, air quality improvement, and increased energy generation by photovoltaic systems (PVs). Newly-obtained data from the Copernicus Sentinel-5P satellite illustrate that some cities have experienced a 45 to 50% reduction in nitrogen dioxide (NO2) concentration compared to the same period in the past year. This reduction has provided two important and unexpected benefits, namely the reduction in environmental pollution (specifically air pollution) and, as a consequence, an increase in the amount of energy generated by PVs.
ABSTRACT
Reconfiguration of the distribution network to determine its optimal configuration is a technical and low-cost method that can improve different characteristics of the network based on multi-criteria optimization. In this paper reconfiguration of unbalanced distribution networks is presented with the objective of power loss minimization, voltage unbalance minimization, voltage sag improvement, and minimizing energy not supplied by the customers based on fuzzy multi-criteria approach (FMCA) using new improved corona-virus herd immunity optimizer algorithm (ICHIOA). The voltage unbalances and voltage sag is power quality criteria and also the ENS refers to the reliability index. Conventional CHIOA is inspired based on herd immunity against COVID-19 disease via social distancing and is improved using nonlinearly decreasing inertia weight strategy for global and local exploration improvement. The methodology is implemented as single and multi-objective optimization on 33 and 69 bus IEEE standard networks. Moreover, the performance of the ICHIOA in problem-solving is compared with some well-known algorithms such as particle swarm optimization (PSO), grey wolf optimizer (GWO), moth flame optimizer (MFO), ant lion optimizer (ALO), bat algorithm (BA) and also conventional CHIOA. The simulation results based on the FMCA showed that all criteria are improved with reconfiguration due to compromising between them while in single-objective optimization, some criteria may be weakened. Also, the obtained results confirmed the superiority of the ICHIOA in comparison with the other algorithms in achieving better criteria with lower convergence tolerance and more convergence accuracy. Moreover, the results cleared that the ICHIOA based on FMCA is capable to determine the best network configuration optimally to improve the power loss, voltage sag, voltage unbalance, and ENS in different loading conditions.
ABSTRACT
Coronavirus 2019 (COVID-19) has globally affected the human mortality rate and economic history of the modern world. According to the World Health Organization, COVID-19 has caused a severe threat to the health of the vulnerable groups, notably the elderly. There is still some disagreements regarding the source of the virus and its intermediate host. However, the spread of this disease has caused most countries to enforce strict curfew laws and close most industrial and recreational centres. This study aims to show the potential positive effects of COVID-19 on the environment and the increase of renewable energy generation in Malaysia. To prevent the spread of this disease, Malaysia enacted the Movement Control Order (MCO) law in March 2020. Implementation of this law led to a reduction in environmental pollution, especially air pollution, in this country. The greenhouse gases (GHG) emission , which was 8 Mt CO2 eq. from January 2020 to March 2020, reduced to <1 Mt CO2 eq. for April and May. The reduction of GHG emission and pollutant gases allowed more sunlight to reach photovoltaic panels, hence increasing the renewable energy generation.
ABSTRACT
This paper multi-criteria designing framework of a hybrid photovoltaic (PV)/wind (WT) clean energy system with battery (BA) storage (HPV/WT/BA) considering cost and reliability assessment is presented to supply an annual load based on real irradiance and wind speed patterns. The designing goal is optimal sizing of the HPV/WT/BA system with the objective of minimizing the net present cost of clean energy generation (NPCEG) as well as the loss of load and CO2 emission cost with satisfying reliability constraint as energy not supplied probability (ENSP) considering stand-alone and grid-connected modes. Decision-making variables include an optimal number of PVs, WTs, batteries, inverter transferred power and PVs angle that is determined optimally using new improved moth flame optimization (IMFO) based on decreasing inertia weight strategy (DIWS) to overcome premature convergence. The designing is implemented for various system combinations in stand-alone mode, including HPV/BA, HWT/BA and HPV/WT/BA systems. The simulation results showed that the HPV/WT/BA is the best combination with the lowest NPCEG and the best ENSP in load supply. The superiority of the IMFO is proved compared to conventional MFO and PSO in designing of different combinations in view of cost and reliability in stand-alone mode. Moreover, the results of HPV/WT/BA optimal designing in a grid-connected mode based IMFO showed the less NPCEG and better ENSP compared to stand-alone mode due to network support with purchasing the network power and CO2 environmental waste emission cost minimization. The results showed that variation of network power, reliability constraint and also inverter efficiency has a considerable effect on designing cost and reliability. Moreover, the results illustrated the reduction of NPCEG and reliability enhancement in the condition of Covid-19.