Energy Storage

This fact sheet from the Environmental and Energy Study Institute describes the role of energy storage in enhancing grid resilience, integrating intermittent renewable energy, and managing peak demand. It details various storage technologies—including pumped-storage hydropower, batteries, compressed air, thermal, hydrogen, and flywheels—comparing their technical specifications, costs, and current global applications.

• Energy storage is critical for managing the intermittency of wind and solar power and improving grid resilience against extreme weather. It allows distributors to buy cheap electricity during off-peak times and sell it during peak demand, reducing the need for backup power plants.
• The International Energy Association (IEA) states that 266 GW of storage is needed globally by 2030 to keep global warming under 2 degrees Celsius, an increase from 176.5 GW in 2017. Bloomberg New Energy Finance projects the market will reach 942 GW by 2040, requiring $620 billion in investment.
• Pumped-storage hydropower (PSH) is the dominant utility-scale storage method in the United States, accounting for 95 percent of such storage. As of 2015, the U.S. had 22 GW of PSH incorporated into the grid, with an increase of 2 GW over the preceding 10 years.
• Lithium-ion batteries dominate the global grid battery market with over 90 percent share. While they offer high energy density and falling costs—with EV battery costs dropping 73 percent from 2010 to 2016—they are typically used for short-term storage of four hours or less.
• Various large-scale storage technologies offer different trade-offs in efficiency and duration. Pumped hydro is highly efficient (70-85%) and long-lasting (30-60 years), while compressed air energy storage (CAES) can reach 70% efficiency if heat is retained. Hydrogen fuel cells provide high energy density and zero emissions when using pure hydrogen, but remain expensive due to the requirement for platinum.
• Electric vehicles (EVs) present both a challenge and an opportunity for the grid. While they increase peak demand during nightly recharging, vehicle-to-grid (V2G) technology allows them to supply energy back to the grid. Additionally, retired EV batteries can be repurposed for stationary grid storage for up to a decade.
• U.S. regulatory and funding initiatives are targeting storage growth. FERC Order No. 841 requires ISOs and RTOs to remove barriers to entry for storage technologies. Additionally, the DOE's ARPA-E committed up to $30 million to the DAYS program to develop technologies capable of powering the grid for up to 100 hours.

APA

Zablocki, A. (2019). Energy Storage. Environmental and Energy Study Institute. https://www.eesi.org/papers/view/energy-storage-2019

Chicago

Zablocki, Alexandra. Energy Storage. Environmental and Energy Study Institute, 2019. https://www.eesi.org/papers/view/energy-storage-2019.

Wikipedia

{{cite report |last1=Zablocki |first1=Alexandra |title=Energy Storage |publisher=Environmental and Energy Study Institute |date=22 February 2019 |url=https://www.eesi.org/papers/view/energy-storage-2019 |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{zablocki2019energy, author = {Zablocki, Alexandra}, title = {{Energy Storage}}, institution = {Environmental and Energy Study Institute}, year = {2019}, month = feb, url = {https://www.eesi.org/papers/view/energy-storage-2019}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }