The deal marks the first time that Capital One, the eighth largest holding bank in the US and a major player in credit cards, has invested in renewables.

SolarCity continues to pin down large financing funds that it uses for the upfront cost of deploying PV systems on rooftops, even as it diversifies into other fund-raising avenues, such as securitization.

In March SolarCity nailed down a $250m facility from a group of lenders including Bank of America Merrill Lynch.