MIDAMERICAN ENERGY
MidAmerican Energy to Launch Energy Storage Pilot Project

MidAmerican Energy Company today (11/8) announced plans to install a utility-scale battery energy storage system.

An energy storage system enables a utility to store electricity for later use.

The battery project provides 4 megawatt-hours of storage capacity and can supply 1 MW of power for up to four hours. 1 MW is enough electricity to power about 900 average Iowa homes.

Chicago-based Invenergy will install the lithium-iron phosphate battery system, housed in two truck-sized steel containers, at a MidAmerican Energy substation in Knoxville. The new system is expected to begin operating by the end of next month.

"This innovative project will help us learn how best to use an energy storage system, and how it can serve our customers in the future," Mike Fehr, MidAmerican Energy vice president of resource development, said. "Energy storage has the potential to allow us to retain energy when customer demand is low and release it during peak usage times. That would give us new options to manage peak loads, enhance overall reliability and help keep electric costs low and affordable for our customers."

Large-scale energy storage has the potential to provide several benefits, including:

Flattening peaks and valleys of electric generation by enabling energy companies to generate and store electricity at times of low demand and release it when demand is high.
Reducing the operating time of peaking generators, which generally run only when there is a high demand and are a relatively expensive form of generation.
Enhancing renewable energy's reliability by storing energy produced when wind speeds and sun exposure are high and using it later.
Improving power quality and prolonging transformer life.

"Energy storage is still in the development stages and the economic feasibility on a larger scale is being assessed as well; however, prices are trending downward," Fehr said. "MidAmerican Energy wants first-hand experience with the technology so we're positioned to quickly and efficiently add it to our system in ways that benefit our customers when the price is right."

About MidAmerican Energy Company
MidAmerican Energy Company, headquartered in Des Moines, Iowa, serves 770,000 electric customers and 751,000 natural gas customers in Iowa, Illinois, Nebraska and South Dakota. Information about MidAmerican Energy is available at MidAmericanEnergy.com and company social media channels.