SolarCity announced on Wednesday, to coincide with Earth Day, the activation of a $1 billion fund that will help fund commercial solar energy systems for businesses, schools, and government organizations across the US.

SolarCityThe fund includes an investment from Switzerland’s Credit Suisse, which was finalized in February and began funding the first projects in late March. This is believed to be the largest such fund of its kind, and is set to finance more than 300 MW of solar projects over the next two years.

“We’re thrilled to support SolarCity’s mission to bring clean, affordable solar energy to businesses across the United States,” said Jerry Smith, a Managing Director at Credit Suisse. “The fund will help more businesses, schools and government organizations save money and help the environment – it’s a win-win scenario. We’re proud to support this progress with our investment.”

This isn’t the first time that SolarCity has teamed up with Credit Suisse, however. According to SolarCity, Credit Suisse has “acted as structuring agent and bookrunner for SolarCity’s industry-first securitization transactions, and also as structuring agent and administrative agent for the facility to finance the purchase of solar energy systems through SolarCity’s new MyPower loan program.”

The fund goes further than simply financing another batch of installations, by focusing on projects which are set to utilize SolarCity’s new technologies.

“Continuing technology improvements, cost reductions and strong financing support from partners like Credit Suisse are making solar economically attractive to a growing number of businesses across the US,” said Brad Buss, SolarCity’s Chief Financial Officer. “SolarCity has installed more than 1,800 commercial solar projects in 21 states—and we’ve barely scratched the surface of the addressable market.”