Investigation of standalone hybrid solar and wind power systems for a small hotel in Changsha, China

Nowadays, China is facing the threat of exhaustion of fossil fuels and negative impacts on the environment resulting from large-scale utilization of these traditional fuels since the majority of electricity in the country is supplied by coal-fired power plants. For the sake of overcoming the disadvantages of fossil fuels and utilizing renewable energy for sustainable development, the paper intends to explore the renewable energy potential of Changsha and propose a suitable renewable energy system for meeting the load demand of a small hotel located in the city. First, based on the natural resources and load demand, fundamental power system configuration and operation strategy for the project are put forward. Then, models of components for the system such as solar PV array, wind turbine, and battery bank are established. Some required data like climate condition, load demand, components parameters, and financial factors are taken into account and input into the HOMER software for simulation and optimization. The optimization results showed that compared to systems that use a single renewable energy source, a hybrid solar and wind energy system has the lowest cost of energy (COE) at US $0.310, which comprises 537 kW PV panels, 10 wind turbines (1,000 kW), 395 batteries (2,729.45 kWh) and a 150 kW converter. A sensitivity analysis of the impact of natural resources, costs of components, and financial factors on the COE of the optimal energy system is conducted, which indicates that wind speed and discount rate are significant contributors to the economic performance of our hybrid renewable energy system. The main contribution of the paper is to provide a concise and reasonable method for researchers to quickly develop hybrid renewable energy systems that can reduce carbon dioxide emission and pollutant discharge while supplying power for energy consumers, which is eco-friendly and helpful for achieving sustainable development.