Tax credits, incentives and rebates are currently available that can significantly reduce the price of plug in solar panels.
In the U.S., homeowners benefit from a 30% federal tax credit. There is no limit on the amount of the credit, which means you could take full advantage and receive a 30% tax credit on a system that powers your entire house. Both principal residences and second homes qualify for the credit, but rentals do not. Be sure to consult a qualified tax professional to discuss your situation. More information on the federal tax credit is available on the the Energy.gov website.
Your state might also have tax credits or incentives.
Visit dsireusa.org to see which benefits are available in your state.