Energy Storage
Key Facts
Invest in ~70%
Of Battery Storage Technology
According to the most recent data, electric companies represent roughly 70 percent of total investment in battery storage technology. Electric companies own, procure, or utilize 96 percent of all mostly grid-connected energy storage today, of which roughly 84 percent is pumped hydropower storage​​.
350% Increase in Installations
From 2016
Investment in advanced energy storage is growing rapidly, with an estimated 1,463 megawatts installed in 2020 alone, up 350 percent from 2016.
Active in 42%
Of Microgrid Projects
Electric companies are active partners in microgrid deployment and are involved in 42 percent of the projects, a virtual quadrupling since 2014.​
What Are the Benefits of Energy Storage?

​Energy storage improves reliability and resiliency for the energy grid and electricity customers.

For Homes
For Businesses
For Electric Companies
Trends & Key Issues
  • ​Battery storage is the fastest-growing energy storage technology today. Total deployed battery capacity increased more than 13 times from 2013 to the end of 2020.​
  • Over the last five years, electric companies were responsible for 70 percent of total energy storage capacity deployed. 
  • Battery energy storage is increasingly cost effective for businesses, households, and electric companies, which are rapidly adopting batteries and using them alone or in combination with other energy resources.
  • As the owners and operators of the energy grid, electric companies are essential to harnessing the benefits of energy storage and microgrids for customers, and can help maximize and optimize the services these technologies can provide.
  • Microgrids provide numerous benefits to the customers they serve, but can also provide important public benefits when deployed optimally, like protection of critical infrastructure and advanced learning of smart grid technologies.

Energy Storage Trends & Key Issues - March 2021​​​​

Company Highlights
  • Ameren Illinois: Thebes Battery Project

    ​Ameren Illinois installed the battery energy storage system in Thebes, Illinois, to provide additional resilience and reliability to the community. The town is surrounded by rough terrain and is served by a single distribution line located in a national forest. Because of its location, power outage restorations are more difficult and time-consuming than in most communities. In the event of an outage, the system automatically supplies power to customers in the area until crews can inspect upstream equipment. Construction of the project took about six weeks, and customers on the circuit now experience fewer and shorter outages.​

  • Berkshire Hathaway Energy – MidAmerican Energy Company: Knoxville Battery Energy Storage System

    ​MidAmerican Energy partnered with Invenergy to deploy a 1 megawatt/4 megawatt hour lithium-iron phosphate battery system at a distribution substation in Knoxville, Iowa. MidAmerican Energy is using this project as a pilot to test the effectiveness of pairing storage with wind generation and to learn how energy storage best serves its customers. The battery charges when demand is low and the supply of wind power is high, and discharges during periods of peak demand. This creates cost savings and enhances MidAmerican Energy’s ability to provide low-cost, renewable energy to its customers. The system can power nearly 900 homes for up to four hours.​

    Learn More.​

  • Dominion Energy: Bath County Pumped Storage Station

    ​The Bath County Pumped Storage Station is the largest pumped-hydro storage facility in the world and the 10th largest power plant in the United States. When operating at full capacity, the facility produces 3,000 megawatts, enough electricity to power nearly 750,000 homes for up to 10 hours. The station is comprised of upper and lower reservoirs connected by tunnels under a mountain. During periods of high demand, water is released into the lower reservoir, generating electricity. When demand is low, the generators are reversed, becoming electric motors and pumping water back into the upper reservoir. The station can go from idle to generating at full capacity in as few as 15 minutes.

    Learn More.​

  • Liberty Utilities (California): Sagehen Microgrid

    ​Liberty Utilities commissioned the Sagehen Microgrid in November 2020. The microgrid allows Liberty Utilities to de-energize four miles of power line in the summer months, when wildfire risk is high. The microgrid consists of 48 solar panels and 53 kilowatt hours of battery storage, with a backup propane generator. The complete system is expected to operate on greater than 95 percent renewable energy. The generator provides power only when there is insufficient charge in the batteries or during no or low solar energy production. The microgrid is a decentralized electricity source and distribution asset that can provide electric power to an isolated area of the distribution system and be synchronized with the energy grid, providing additional power and load balancing.​

  • Southern Company: Georgia Power Smart Neighborhood

    ​The Georgia Power Smart Neighborhood consists of a neighborhood of 46 “smart” townhouses that each feature behind-the-meter energy storage, private solar, connected devices and appliances, buildings-to-grid communication, and energy efficiency measures. Residents can use these resources to supplement the power they buy from Georgia Power, lowering their electric bills. Georgia Power developed the neighborhood under a research and development agreement that includes Southern Company, the U.S. Department of Energy, Oak Ridge National Laboratory, the Electric Power Research Institute, and local homebuilders and technology vendors. 

    Learn More.​

  • Alliant Energy: Decorah Energy Storage Project

    ​Alliant Energy built the 2.5 megawatt/2.922 megawatt hour system on a circuit in Decorah, Iowa, that soon will reach capacity as increasingly more customers install private solar. The system helps increase the reliability, resilience, and hosting capacity of the local energy grid by storing excess solar power generated during the day and releasing it during the evening peak demand period. The system also regulates voltage through its voltage variation function, and its oversized inverter provides increased variation capability. Alliant Energy partnered with the U.S. Department of Energy (DOE) and the Iowa Economic Development Authority (IDEA) to build this battery storage solution and secured a $250,000 cost-share from DOE and a $200,000 cost-share from IDEA. 

    Learn More.​

Additional Resources
June 2021
The AES Corporation and Edison International/Southern California Edison Win 93rd Annual Edison Award
August 31, 2020
EEI Response to Request for Information Regarding Energy Storage Grand Challenge
March 2021
SDG&E’s Battery Project Continues to Advance Clean Energy Microgrids
May 2020
SCE Will Add Energy Storage Projects
June 2021
Leading the Way: U.S. Electric Company Investment and Innovation in Energy Storage
Harnessing the Potential of Energy Storage