Residential Compressed Air Energy Storage System Using Photovoltaic Solar Power and Concentrating Solar Power

As solar photovoltaic penetrates residential markets the importance of energy storage devices increases. A compressed air energy storage system is evaluated for a 150 m2 home in a climate with warm summers and mild winters. As an alternative to battery storage, air is compressed into a storage vessel and be released at a later time to run an expander to generate electrical power. A compressed air energy storage system is modeled to evaluate the operating conditions such as pressures, temperatures, time durations, compressor speeds, expander speeds, heating, and power requirements of the system. The system encompasses a reciprocating compressor, expander, air heating unit, concentrating solar collectors, and 50 m3of air storage. The compressor will charge the air storage tank from an initial pressure of 630 kPa to a final pressure of 1150 kPa. The charging of the compressed air energy storage system will have a duration of 9.25 hours, while discharging of the compressed air energy storage system will have a duration of 11.75 hours. The compressed air energy storage system can produce 6.5 kWh of electrical energy during discharging and consumes 23.1 kWh of electrical energy during charging. This is an efficiency of 28.1% when converting electrical energy from photovoltaic solar cells back to electrical energy via a generator driven by expander.