Briefing on Coffeen Solar BESS

Coffeen Solar BESS is a 46 MW solar and battery storage plant in Illinois, operated by Vistra Corp. and contributing 85 GWh annually to the MISO grid.

Overview

• Coffeen Solar BESS is an operating plant since 2024.

• It is located in Illinois and owned by Vistra Corp., which also serves as the EIA operator.

• The plant is connected to the MISO (Midcontinent) ISO grid.

Fleet Details

• The plant has 2 generators utilizing Batteries and Solar Photovoltaic technologies.

• It has a capacity of 46 MW.

• Key similar plants include Solar Star 3, Solar Star 4, and Sanborn BESS 4.

Generation Profile

• The plant has an annual generation of 85 GWh with a capacity factor of 21.0%.

• Recent monthly generation figures include 6 GWh in October 2025, 4 GWh in November 2025, and 3 GWh in December 2025.