NEW YORK — Google Inc. is making its largest investment yet in clean energy in an effort to help private homeowners put solar panels on their rooftops.

The $280 million deal with installer SolarCity is the largest of its kind. SolarCity can use the funds to pay for a solar system that it can offer to residents for no money down. In exchange, customers agree to pay a set price for the power produced.

Google earns a return on its investment by charging SolarCity interest to use its money and reaping the benefits of federal and local renewable-energy tax credits.

“It allows us to put our capital to work in a way that is very important to the founders and to Google, and we found a good business model to support,” said Joel Conkling of Google’s Green Business Operations.

Google co-founder and chief executive Larry Page wants Google’s operations to eventually produce no net greenhouse gas emissions. To this end, Google has invested in wind farms in North Dakota, California and Oregon, solar projects in California and Germany, and the early stages of a transmission system off the East Coast meant to foster the construction of offshore wind farms. The SolarCity deal brings the total value of these investments to $680 million.

This type of fund Google is creating is common in the residential solar industry, A typical rooftop solar system costs $25,000 to $30,000, too much for many homeowners to lay out. Instead, solar providers like SolarCity and competitors SunRun and Sungevity can pay for the system with money borrowed from a bank or a specially designed fund. The resident then pays a set rate for the power generated. The rate is lower than or roughly the same as the local electricity price.

A typical 5-kilowatt system will generate about 7,000 kilowatt-hours of power in a year, or about 60 percent of the typical household’s annual use.