Energy storage is playing a growing role in US efforts to strengthen grid reliability as electricity demand increases. According to the Solar Energy Industries Association (SEIA), the country has gone from installing around 6,000 MWh of energy storage capacity in 2020 to more than 175,000 MWh today.

That capacity is enough to power more than five million homes for an entire day on a single charge, according to the association. The expansion comes as the US power system faces rising electricity demand from data centers, advanced manufacturing and extreme summer heat.

Energy storage allows grid operators to store electricity when it is abundant and less expensive and dispatch it when demand rises. SEIA says this flexibility can help reduce pressure during peak periods, strengthen grid reliability and mitigate price fluctuations.

Since 2010, 13 states have introduced policies aimed at increasing their energy storage capacity. SEIA identifies California, Nevada, Illinois, Virginia and Massachusetts as five examples of states incorporating storage into their power strategies.

California surpasses 21,000 MW

California became the first US state to establish an energy storage procurement target in 2010, setting a goal of 1,825 MW by 2024. The state subsequently exceeded that target by a wide margin.

California now has more than 21,000 MW of energy storage capacity and has established additional targets for long-duration storage.

The growing role of batteries is also becoming increasingly visible in grid operations. On August 1, 2026, battery discharge on California's main power grid exceeded 13,000 MW for the first time, supplying around one-third of the state's total electricity demand at the time.

Source: SEIA

Nevada exceeds its 2030 target

Nevada enacted bipartisan energy storage legislation in 2017. The state's Public Utilities Commission subsequently established incremental targets aimed at reaching 1,000 MW of capacity by 2030.

Nevada has already surpassed that goal, with approximately 1,700 MW currently installed. According to SEIA, the state now ranks fourth nationwide for installed energy storage capacity.

Illinois targets 3,000 MW by 2030

Illinois has incorporated energy storage into its electricity strategy through the Clean and Reliable Grid Affordability Act, signed into law by Governor JB Pritzker earlier this year.

The legislation directs the Illinois Power Agency to procure 3,000 MW of energy storage by 2030. It also provides incentives for standalone storage projects and establishes a Virtual Power Plant program to use distributed energy resources, including residential batteries, during periods of peak electricity demand.

SEIA estimates that the measures could generate around $13.4 billion in electricity bill savings for Illinois households and businesses over the next 20 years.

Virginia expands storage targets amid data center growth

Virginia is also increasing its energy storage ambitions as rapid data center development contributes to rising electricity demand in the state.

In 2026, Governor Abigail Spanberger and state lawmakers expanded the storage targets originally established under the 2020 Virginia Clean Economy Act.

Virginia is now targeting an additional 16,780 MW of short-duration energy storage by 2040 and 4,520 MW of long-duration storage by 2045.

Massachusetts surpasses 1,500 MWh

Massachusetts established a target in 2018 to reach 1,000 MWh of energy storage capacity by 2025. The state exceeded that target and now has more than 1,500 MWh of storage capacity.

Governor Maura Healey's administration is continuing efforts to expand storage deployment, particularly long-duration technologies. Legislation signed in 2024 and an executive order issued this year form part of the state's strategy to increase capacity.

Energy storage expands across the US

SEIA notes that storage deployment is not limited to these five states. In 2025, the Georgia Public Service Commission unanimously approved an Integrated Resource Plan that includes more than 1,500 MW of new energy storage, while Texas has become the country's second-largest storage market.

Although policy approaches differ from state to state, SEIA argues that storage provides a flexible resource capable of responding to rising electricity demand, delivering power during peak consumption periods and supporting grid reliability.

The technology is therefore becoming an increasingly important part of state energy strategies as the US power system responds to new sources of electricity demand and the need for resources capable of rapidly balancing the grid.