Affordable Rooftop Solar in the United States

By 2017, more than half of U.S. states could have rooftop solar that's as cheap as local electricity rates.

Rooftop solar costs are falling

 Since 2007, the cost of installing an average-sized rooftop solar system has nearly halved. In fact, after accounting for tax credits, rebates, and other support, in leading states a 5 kilowatt system could cost homeowners less than $10,000.
Many homeowners have the option of leasing, potentially paying nothing for installation and instead paying ongoing monthly fees.

Solar is increasingly affordable everywhere

The plunging costs of solar systems and the broad availability of sunlight mean that rooftop systems are increasingly able to compete with electricity from the grid around the country. By comparing average local electricity costs with the projected average national price of an installed rooftop solar system, we can estimate the percentage of states that may have—or may soon have—competitive rooftop solar power.
The result? By 2017, more than half of U.S. states could have rooftop solar that’s as cheap as grid electricity—even without considering state and local incentives. Most regions already have a state that’s cost competitive, and many more states may soon come online.

The solar revolution is underway

In 2006, some 30,000 U.S. homes had rooftop solar systems. By 2013, that number had grown over 1000 percent to almost 400,000 homes.
This number will likely continue to increase at an impressive rate. Projections from the U.S. Energy Information Administration suggest we’re headed to almost 1 million homes by 2020. The U.S. Department of Energy projects that significant solar cost reductions would get us to close to 4 million.
source: http://www.ucsusa.org