Massachusetts Electric Co. and Nantucket Electric Co. d/b/a National Grid on Sept. 16 asked the Massachusetts Department of Public Utilities for confirmation that a solar facility with integrated battery storage is the type of investment contemplated by the department’s pre-approval of cost recovery set forth in D.P.U. 14-01.
Fouad E. Dagher, Director of Products and Energy Services in the Customer and Business Strategy group within the Customer organization of National Grid USA noted in supporting testimony that D.P.U. 14-01 was a pre-approval of expenses associated with the ownership, operation and maintenance, real estate leases, and property taxes associated with projects developed in the company’s Solar Phase II Program.
Dagher wrote: “With this filing, the Company requests confirmation that its pre-approval for cost-recovery associated with projects owned and operated by the Company pursuant to the Program includes projects that are comprised of solar generation with integrated battery storage. Specifically, the Company requests that the Department confirm that the Company has pre-approval for cost-recovery associated with its proposed investment in a specific solar/storage project proposed to be located in Shirley, MA (the ‘Shirley Project’) pursuant to the terms and conditions set forth in D.P.U. 14-01. The Shirley Project would consist of an integrated Tesla Gen-II lithium-ion battery bank into a proposed solar site in Shirley, Massachusetts, on Patterson Road, to the west of the Company’s Ayer Substation.
“The Company understands that while the Department will not revisit whether the Company should have proceeded with any particular investment, the Department will review the prudency of the Company’s actions in developing such facilities.”
The company seeks to integrate a Tesla “Gen II” lithium-ion 500 kW/1,000 kWh battery bank to the proposed Shirley site. The estimated cost of the battery bank is $1 million, which includes the cost and installation of the battery, commissioning and project management. This cost represents about 1% of the $84.86 million program cap approved by the department. When the battery storage is installed in conjunction and integrated with a solar generation facility there could be a potential for an investment tax credit (ITC) equivalent to 30% of the company’s cost, which would reduce its ownership costs by approximately $300,000. The total ownership cost for the Shirley Project, including the battery bank, is estimated to be $3.6 million per mega-watt, which is within the approved capital budget of $4.2 million per mega-watt.
The application is under review, with a hearing officer to handle the case assigned on Sept. 24.