Thermal Energy Storage as an Enabling Technology for Renewable Energy

A variety of electrical energy storage technologies have been proposed to help integrate variable and uncertain renewable energy resources such as solar PV and wind. An emerging electricity storage technology is cold storage for space cooling. Since peak electricity demand in most of the United States is driven by air conditioning, cold storage provides an opportunity to store low value renewable generation occurring during off-peak periods. This includes some unusable mid-day solar generation that can occur at high penetration. Advantages of cold storage include potentially low cost relative to several other storage technologies, as well as very high effective round trip efficiency. A significant disadvantage is that cold storage is tied to a single application (space conditioning) which limits its flexibility. This paper explores the temporal characteristics of space cooling demand and the benefits of cold storage to reduce renewable energy curtailment in the southwestern United States.