Optimal Design and Techno-Economic Analysis of a Hybrid System to Supply a Remote Fishpond with Electricity and Heat

This paper deals with the design of a hybrid system for the generation of electricity and heat that will supply a remote fishpond in eastern Serbia. The proposed hybrid system consists of a micro-hydro power plant (MHPP), a photovoltaic (PV) generator, a combined heat and power (CHP) unit with one diesel generator, batteries, a converter, a thermal load controller (TLC), and a boiler. A comprehensive techno-economic analysis is performed in the HOMER Pro software, which evaluated and compared 12 possible configurations with different combinations of system components. The results show that the optimal system has the lowest total net present cost (NPC) and the lowest levelized cost of energy (COE) amounting to 284421.0 $ and 0.178 $/kWh, respectively. Compared to a diesel/batteries/converter/boiler hybrid system, the proposed system produces 65.4 % less greenhouse gas (GHG) emissions, while the shares of electricity, heat, and renewable energy generation are increased by 31.1 %, 5.0 %, and 51.2 %, respectively. It is shown that covering the demand for heat by regenerating the waste heat from the diesel generator and excess electricity from renewables contributes to reducing the total cost of the system and the GHG emissions. This finding finally emphasised the necessity of applying TLCs in off-grid hybrid systems.