Emery County approves 300 MW Horn Shadow battery storage project

The Emery County Commission voted Jan. 6 to approve a Level 3 conditional use permit for a 300-megawatt battery energy storage system (BESS) to be sited alongside the Horn Shadow solar project.

Liz Hayden, head of project development for the project sponsor, said the BESS would be matched 1:1 with the Horn Shadow solar capacity. Hayden told commissioners the BESS footprint would be about 30 acres for the battery containers and roughly 56 acres when fencing, roads and perimeter buffers are included. She said construction could start in mid-2026 and take up to 18 months to complete for commissioning work, and estimated the proposed expansion represents about $360,000,000 in new investment in Emery County.

Supporters described storage as a way to move low-cost solar energy into evening and morning hours, improving affordability and grid utilization. Hayden said the storage would interconnect using the existing Horn Shadow project substation and would not displace the solar interconnection capacity that was studied assuming multiple local generation sources operating together.

Commissioners asked about battery replacement and end-of-life handling. Hayden said the system is typically augmented over time rather than uninstalling containers, and a company representative noted there is an industrial recycling and disposal supply chain for lithium-ion batteries at large scale. She also said the developer had space to add capacity over time and described the initial installation as an “anchor” system with modest overbuild.

A motion to approve the Level 3 conditional use permit was moved and seconded; Commissioners Warwood, Leonard and Jensen voted aye and the motion passed.

The permit approval allows the developer to advance final engineering, permitting and CRA revenue discussions with county stakeholders; commissioners did not adopt revenue figures or tax-agreement terms at the meeting.