The Iowa Utilities Board (IUB) has given the green light to a solar and storage project from National Grid Renewables, with a 50MW battery energy storage system (BESS).

The IUB last week (21 April) granted an electric generating certificate and an order granting a request for waivers and a certificate of public convenience, use and necessity to the Grand Junction Solar project.

The solar-plus-storage project in Greene County pairs 100MW of solar PV a 50MW BESS. The BESS will optimise the solar PV array, storing electricity generated by the solar panels when it is abundant and discharging it to the grid when most needed. It did not reveal the discharge duration of the BESS unit.

The project is being developed by National Grid Renewables, part of the UK grid operator National Grid. It will cover approximately 1,103 acres of which four acres will be for the BESS. It will connect to the grid, operated by independent system operator MISO, via a generation-tie line extending to the Karma substation.

The order from the IUB requires Grand Junction to seek IUB approval for either an enlargement or transfer of ownership of the project to another entity. It also grants Grand Junction’s request to waive a public evidentiary hearing and associated procedural requirements under Iowa law.

Grand Junction Solar will need to file final design plans and evidence of having obtained all city and county permits to the IUB before construction starts. If it doesn’t complete the project within the two years after a final permit is issued it needs to file an a new application.

The IUB similarly granted certificates of use to a solar-plus-storage project from NextEra in August last year, with a 300MWh of co-located BESS.