ABSTRACT
Electric power systems today have limited storage capacity. Both in the United States and worldwide, storage makes up less than 3% of generation capacity (EPRI, 2010). This lack of storage forces grid operators to continuously balance generation and load and prevents the electricity sector from operating as a conventional competitive market that relies on inventory. Pumped hydropower storage (PHS) is the predominant storage technology today, making up 99% of all deployed storage capacity. However, PHS requires suitable locations with a height difference between reservoirs. R&D investments have led to rapid improvements in advanced battery technologies. Recent advancements suggest batteries may approach cost parity with PHS at $300/kWh.
