The Connecticut Department of Energy and Environmental Protection (DEEP) has denied energy storage projects proposed by Eversource and Avangrid, according to the Hartford Business Journal.
DEEP said the expected costs of the projects would have outweighed benefits to ratepayers, but told the utilities they could revise and resubmit them to the state’s Public Utilities Regulatory Authority.
- The projects would have installed storage devices at substations to improve grid operations. DEEP did not post its decision online and did not respond to requests for comment.
Utilities are beginning to appreciate the grid benefits of energy storage, but they still need to demonstrate the cost effectiveness of those projects.
Connecticut utilities Eversource and Avangrid have reportedly been sent back to the drawing board to work on their cost projections for two demonstration projects.
Avangrid proposed a storage system for a substation in Milford at a cost of $5.6 million and with annual costs of $300,000.
Eversource proposed a 6 kWh storage system at a substation in Stafford that is prone to unstable voltage, especially during peak summer demand. Eversource said the system would cost up to $13 million, not including annul operation costs that could total as much as $33 million over the expected 22 year life of the equipment.
The storage facility would give Eversource greater flexibility to integrate the residential and commercial solar power arrays on its grid, Camilo Serna, vice president strategic planning and policy for Eversource, told the New Haven Register last year when the projects were proposed.