US utility Hawaiian Electric Company announced on May 2 it is planning to build a total of 120MW of lithium ion grid-scale energy storage to ensure its security of supply, allow for increased renewables penetration and reduce fossil fuel use on the Oahu electric grid.
The projects are subject to approval by the Public Utilities Commission, but if approved they will be owned and operated by the utility with building work starting this October.
The first project will include a 100MW/100MWh system at Hawaiian Electric’s Campbell Industrial Park Generating Station. It is due to begin providing contingency and regulating reserve services by October 2020 at an estimated cost of $104 million.
The second project, a 20MW/80MWh, $43 million system, will support the 20MW West Loch Solar system under construction at Joint Base Pearl Harbor-Hickam, West Loch Annex.
If agreed, the company hopes to start construction by October 2019 with the system in service by February 2020.
Ron Cox, Hawaiian Electric senior vice president for operations, said the projects would enable more renewable integration into the grid as the company moves toward a 100% renewable energy output.
Because storage will be paired with the solar facility, it will be eligible for the Federal Investment Tax Credit that will save customers 30% of what the project would cost without the credit.
To maximize the credit Hawaiian Electric is also accepting proposals for new grid-scale renewable generation that includes storage.
The current tax credit runs until 2019, when it will drop to 26% through to 2020, then fall a further four percentage points through the end of 2021. By 2022 it will be 10% and remain in effect for the next two years.