Combination of air-based high-temperature heat and power storage system with an Organic Rankine Cycle for an improved electricity efficiency

High-temperature heat and power storage technology is an electricity storage concepts recently proposed and being investigated. This technology stores electricity as high-temperature heat and then, as needed, reclaims it to co-generate heat and electricity via a conventional power production method. Based on the power block design, this technology may come in either a ‘steam-based’ or an ‘air-based’ configuration. Regardless of the configuration, this technology offers a very high overall energy efficiency (over 80%) but low power-to-power efficiency (about 32%). Relying on the fact that electricity is going to be certainly a more pricy and critical energy kind than heat in the future, the current study suggests combining the air-based high-temperature heat and power storage and an Organic Rankine Cycle together to improve the electricity production efficiency of this storage technology. The proposed combined system is thermodynamically analyzed and compared to the conventional configuration of that. The results show that this combination results in a significantly enhanced electricity efficiency, from 32% in the conventional configuration of the system to 43% in the proposed combined cycle.