Current Storage Options
The first step in reimagining energy storage possibilities is to understand some of the most promising technologies available today, including both battery technologies and pumped hydroelectric storage.
Lithium-ion is the dominant storage technology for several reasons. Lithium-ion batteries (LIB) feature high energy density and are relatively lightweight, making them ideal for portable devices and electric vehicles. In addition, the batteries have appealing life cycles and compactness, as well as round-trip energy efficiency that exceeds 85 percent, according to the California Energy Commission.
Since the LIB’s commercial introduction in 1991, the technology has continued to gain favor. Though early applications were limited to portable consumer electronics, lithium-ion technology now is widely used throughout the auto industry. As of 2016, global LIB production volume was 28 gigawatt-hours (GWh). More recently, electric vehicles surpassed portable devices as the largest market for these batteries.
Because the same components can be used in both cars and renewable energy storage, electric utilities have found lithium-ion technology more easily scalable than storage options that haven’t been developed for customer applications yet.
“With proper planning, utilities can almost buy lithium-ion products off the shelf,” says Peter Boos, who analyzes energy markets and works with storage technology at Burns & McDonnell. “Currently, it is the only solution they can scale and install within a few months.”