Australian investment house Quinbrook Infrastructure Partners and US developer Primergy Solar have closed $1.9bn in construction debt and tax equity financing for the Gemini PV-plus-storage project in the state of Nevada, set to be the largest-ever US solar hybrid development once online in the fourth quarter of 2023.

Debt financing for the megaproject, which will wire together a 690MW PV plant and a 1,417MWh (380MW) battery energy storage system on a site on federal land in the Mohave Desert, includes $1.3bn in credit facilities, including a construction/term loan, tax equity bridge loan, and a letter of credit facility.

The four coordinating lead arrangers for the financing were the Bank of America, KeyBanc Capital Markets, MUFG Bank, and Norddeutsche Landesbank Girozentrale. Voya Investment Management provided the $95m mezzanine debt facility.

Quinbrook and Primergy, one of its wholly owned portfolio companies, said Bank of America and Truist Bank provided $532m in tax equity, a commitment believed to be the largest single-asset tax equity solar financing ever completed in the US.

“With the suppliers and contractors engaged and the financing secured, we are ready to begin construction on this unprecedented project,” said Ty Daul, CEO of Primergy.

From its site 53km (33 miles) northeast of Las Vegas, the project would be able to generate enough clean energy to power the city, the US’ 26th biggest conurbation and internationally renowned resort destination populated with mega casino-hotels,

The project has a 25-year power purchase agreement with NV Energy, the state’s dominant electric utility that is owned by Warren Buffett’s Berkshire Hathaway conglomerate.

Last month, Primergy selected Kiewit Power Constructors as Gemini’s engineering, procurement, and construction partner and IHI Terrasun as the battery ESS integrator. Maxeon Solar Technologies, spun off from SunPower in 2020, will provide the bifacial solar modules from a US plant.

The Energy Information Administration expects utility-scale solar to account for almost half of 85GW of planned power generating capacity installed this year and in 2023 with 60% paired with battery storage, as new wind development slows in the discontinuation of federal subsidy support.