Abstract
Solar energy-based hybrid renewable energy generators are techno-economically designed for various standalone uses such as far-distance area electrification, commerical building electrification, polygeneration, and industrial application. This article attempts to address the problem of high cost of energy of such generators, which needs to be optimized. The research gap is that there is hardly any work on techno-economic optimization of such generators using an initial sizing technique, thereby resulting in a design with higher cost of energy. In this work, a hybrid renewable energy generator comprising solar photovoltaic-biogas-battery storage is techno-economically optimized with the aim of minimizing its cost of energy for electrification of a radio-broadcasting station in India by using simulation software called hybrid optimization model for electric renewables. An initial sizing strategy has been proposed in the modeling of the hybrid system. Optimal designs are obtained under different scenarios like in the standalone mode with and without capacity shortage fraction and in grid-connected mode with scheduled and random outages. The results show that during initial sizing in the standalone mode, consideration of larger size (25 kW) of the component with lower unit capacity cost (biogas unit) and higher load sharing by it (102,625 kWh/year) in the energy management of the hybrid design with a small capacity shortage (5%) reduces the levelized cost of energy to 0.0956 $/kWh compared to some of the literature designs. Of all the optimal designs, the grid-connected system has the lowest levelized cost of energy of 0.0873 $/kWh with a renewable fraction of 0.821. The present work contributes to the component size planning of hybrid renewable energy generator to generate lower levelized cost of energy. The novelty of the present work is that in the component size planning in the standalone mode, following the initial sizing strategy, if the component with lower unit capacity cost shares majority of the load, then the levelized cost of energy with or without grid-connected mode can be further reduced compared to some existing designs, which can be verified from the simulation results. Therefore, the present results will be useful for component planning and sizing of hybrid renewable generators so as to preset the size of its components as per their unit capacity cost to result in a lower cost of energy.
