A second helping of $25 million in financing is expected to spur 1,000 Phoenix, Ariz. residents to install solar on their homes.

National Bank of Arizona and the city of Phoenix announced the launch of its Solar Phoenix 2 project earlier this week.

The project will provide $25 million in financing from National Bank of Arizona to allow residents to install leased solar systems on their roofs with no upfront cost. The leased systems are expected to save utility customers in Arizona Public Service and Salt River Project utility districts 10 to 15 percent per month on their electricity bills.

It all started in 2009 when Craig Robb was the CFO of the National Bank of Arizona.

The bank installed a couple hundred kilowatts of solar photovoltaic panels on its roof, said Robb, who is now managing director of the National Bank of Arizona and Zions Energy Link.

At the ribbon-cutting for the solar panels, the Phoenix mayor joked that it would be great if the bank backed a community solar fund.

“It wasn’t like, ‘oh, thanks mayor for putting us on the spot,’” Robb said. “We’d talked about it already.”

The first Solar Phoenix project was only open to Phoenix residents. And 445 Arizona homeowners installed leased solar systems on their roofs in 2010. Total, the systems generate about 2.8 megawatts of power.

He said the program’s creators expected most homeowners to install 3-kilowatt systems, but most ended up putting 6 kilowatts on their roofs.

“Success begets additional activity,” Robb said.

The program worked so well the first time that the city and the bank decided to do it again and the National Bank of Arizona is promising another $25 million for residential solar lending.

Robb said he expects to more than double the amount of solar installed with the same amount of money and the same amount of time this time around.

The prices of solar panels have dropped dramatically since the first project in 2010 and efficiencies in the industry and subsidies have taken hold. Even with 6-kilowatts systems, Robb said he expects the program to be an even greater success than the first.

US Energy Secretary Steven Chu has formally recognized the program as one of the most effective ways to help a community go solar.

“We could easily approach 1,000 solar customers,” Robb said.