Thermal management of the waste energy of a stand-alone hybrid PV-wind-battery power system in Hong Kong

This paper firstly investigated the thermal management of wasted energy from a stand-alone hybrid solar-wind-battery power system. The total dump load or waste power can be up to 50% of total system power yield, and therefore waste energy management is urgent with high necessity. A new phase change material (PCM: Ba(OH)₂·8H₂O) with high storage capacity is introduced for the thermal management of hybrid power system. Different renewable energy configurations with different battery storage capacities are simulated and investigated. For different scenarios, the ratio of the captured thermal energy from waste energy to total solar/wind power output ranges from 24.45% to 72.48% regarding all system losses. The cases without battery bank are featured by high thermal energy amount/ percentage (waste energy) and high power supply failure. Typical results show that, the total yearly renewable power output is 173,877 kWh with only 51.99% directly for demand load, and 57,672 kWh with 33.17% can be effectively stored in the thermal storage tank as heat, which can supply about 136 people’ heat demand per year. Compared with the water tank, the PCM thermal storage tank can save much space and land because of its high energy density. Appropriate thermal management of stand-alone hybrid solar-wind-battery power systems is necessary and feasible.