“As we said when we made our first residential solar investment, we think it makes a lot of sense to use solar photovoltaic (PV) technology—rooftop solar panels—to generate electricity right where you need it at home,” says Google Director of Green Business Operations Rick Needham. “It greens our energy mix by using existing roof space while avoiding transmission constraints, and it can be cheaper than drawing electricity from the traditional grid.”

“Purchasing a solar system is a major home improvement, but the upfront cost has historically been one of the biggest barriers for homeowners,” Needham adds. “Solar installers across the country don’t always have the resources to find financing for customers, or the capital to provide it themselves. And for investors like Google, banks and others, it can be difficult to enter a fragmented solar market with many companies, and get connected to individual homeowners.”

Clean Power Finance has an open platform to connect installers and investors (Google in this case) to help homeowners finance the changes.

“Solar installers sign up with Clean Power Finance to get access to the company’s comprehensive sales solutions, including consumer financing from investors, like the Google fund,” explains Needham. “This enables installers to sell more systems and grow their business. The installer builds the system, the investor (in this case, Google) owns it, and homeowners pay a monthly payment for the system, at a price that’s often less than paying for energy from the grid. Maintenance and performance are taken care of by Clean Power Finance and its network of installers.”

You can see more about Google’s various investments in clean energy here. They include, in addition to the Clean Power Finance investment, $280 in SolarCity (solar for residential rooftops), $10 million in Brightsource (solar), a 37.5% equity stake in Atlantic Wind Connection, $157 million in Alta Wind Energy Center, $100 million into Shepherd’s Flat (wind farm), $38.8 million into Peace Garden wind farms, and about $5 million in Photovoltaics (solar).

Google has had solar panels on its own headquarters since 2007.

Through its nonprofit organization Google.org, the company is exploring a number of alternative energy initiatives to also find more efficient ways to power its data centers around the world.

On the Official Google Blog, Jeffery Greenblatt, Google.org’s climate and energy technology manager, wrote that the cost of Google’s plan would be significant, exceeding $4 trillion, it could result in a net savings of $1 trillion over its 22-year span.

Greenblatt wrote that the "Clean Energy 2030" plan would involve heavy investments in transmission capacity for wind and solar power in the "Great Plains and desert Southwest" to help cut 88 percent of fossil fuel use and 95 percent of carbon-dioxide emission by 2030.

In addition, Greenblatt wrote that geothermal energy, or natural energy that can be tapped beneath the Earth’s surface, is the "sleeping giant" of alternative energy.  Geothermal- energy systems have the potential for "extremely rapid growth if key technologies can be proven in the next few years," he said.

Through Google.org, Google has invested in geothermal-energy company Potter Drilling, which is developing technology to pierce hard rock and has provided a grant to Southern Methodist University’s Geothermal Lab.