DTE Energy and sonnen have begun a two-year home-battery pilot in Ann Arbor, testing whether coordinated storage can help meet energy needs at lower cost and strengthen reliability.
The companies announced the launch Oct. 29, after the Michigan Public Service Commission (MPSC) approved the program Sept. 10. DTE describes it as Michigan’s first residential battery virtual power plant pilot. The project is based at Veridian at County Farm, a 170-home mixed-income community developed by Thrive Collaborative.
DTE said the system is expected to connect nearly 100 homes. The MPSC order covers a plan involving up to 100 residential batteries. Each standard sonnen battery provides 4.8 kilowatts of power and stores 20 kilowatt-hours of energy. Sonnen’s energy-management system will coordinate the batteries as a shared grid resource.
The pilot will track enrollment, charging patterns, participation in dispatch events and how solar power is used with the batteries. The commission’s order also lists customer experience, operational performance and cost-effectiveness as areas for evaluation. The savings and reliability benefits are goals for the trial, not measured results.
DTE proposed annual payments of $105 per kilowatt of battery capacity for participants who allow the utility to schedule battery dispatches. Payments would be capped at $504 per battery each year. DTE estimated the two-year pilot would cost $500,000 and asked to account for those costs as a regulatory asset. The commission approved the pilot but did not decide whether customers will ultimately bear its costs.
DTE Energy President and CEO Joi Harris said the pilot would test an approach that could eventually lower the cost of meeting growing energy needs and strengthen reliability. The MPSC also urged DTE to address obstacles to valuing and dispatching battery exports during the first year and to prepare to export power in the second.
The order gives commission staff 120 days from launch to set up a workgroup on possible second-year changes and barriers to virtual power plants.
