
Stored capacity to produce electrical energy is not a new idea. For most of the history of the power industry, system planners have considered storage to be primarily the energy in coal piles outside power plants, or gas in pipelines, or water stored behind hydroelectric dams.
Today, as decarbonization efforts accelerate, existing and emerging battery technologies are becoming the answer to energy storage needs — meeting the challenge of maintaining grid stability in an era of dynamic change.
Cleaner and Greener
System planners today carefully track the amount of energy storage either recently installed or about to come online. California and an increasing number of other states with target dates for reducing or eliminating carbon sources from the grid are counting on renewables to get them there. It is becoming increasingly necessary to pair these renewable sources with many gigawatts of energy storage.
Although other forms of clean energy storage like pumped hydro are available, large-scale battery installations have accounted for most of the recent growth in storage within the U.S.
According to BloombergNEF, a total of 4.2 gigawatts (GW) of battery energy storage was connected to the U.S. grid in 2021, bringing the total grid-connected battery capacity to 6.6 GW. Looking to the future, more than 8 GW of additional battery storage is expected to be connected to the grid by 2027. This will be accompanied by an additional 35 GW of solar power over that same period.
Nearly all of the current battery storage is provided by lithium-ion batteries, the same technology being installed in electric vehicles and many consumer electronic devices.
According to Chris Ruckman, vice president for energy storage at Burns & McDonnell, the cost competitiveness of lithium-ion battery technology is making it the dominant force in the industry — a fact that is effectively stalling development of other types of battery technologies, such as flow batteries, that offer longer durations of energy output.
The cost of lithium-ion battery packs has dropped to around $150/kilowatt-hour (kWh) today, compared with around $1,600/kWh in 2010. What’s more, today’s price even reflects a recent rise in battery costs due to global supply chain issues and other factors.
“This train is not slowing down,” Ruckman says. “Even with recent cost increases, projects continue to get built. I view this as an encouraging sign that the economics of these projects are still viable. The numbers still make sense even when materials costs are rising.”
The large-scale energy storage market is benefiting tremendously from the fact that about 80% of lithium-ion batteries are made for EVs and consumer electronics. The large scale of this manufacturing — coupled with continuing research and development to improve energy density and address past safety concerns — is accruing as a major benefit for the power industry.