Performance analysis on a hybrid system of wind, photovoltaic, thermal, storage, CO2 sequestration and space heating

The combined heat and power generation (CHP) is an efficient and economical solution to the intermittency and instability faced by renewable energy power and however, the heat-power coupling lowers its regulation depth. Thermal energy storage is a valid measure to solve the above problem, however, the major bottleneck is lack of thermal energy storage ways with large capacity, high efficiency, low cost and longtime simultaneously. Here, a novel hybrid system of wind-photovoltaic-thermal-storage-CO₂ sequestration-space heating is proposed, which can store thermal energy and sequestrate CO₂ in saline aquifer simultaneously. The results show heat extraction power, energy storage capacity, energy storage density and thermal recovery efficiency for the hybrid system are respectively 6391.14 kW, 66263.36 GJ, 23276.37 kJ/m³ and 81.17 %. The hybrid system extends the adjustable range of CHP from 200 MW to 700 MW through thermal energy storage and heat-power decoupling, thus accommodating more renewable energy power. The amount of sequestrated CO₂ captured from exhaust gas of thermal power station is 2,306,880 tons, equivalent to 854,400 tons of standard coal in terms of carbon dioxide emissions. In addition, the repeated injection and extraction of working gas in the hybrid system accelerates CO₂ solubility in saline aquifer.