Here's how the tax benefits work, using round numbers.
Federal Credit available for solar systems – 30% - or $120,000 credit. (Business Energy Investment Tax Credit)
So – out of the gate the net cost of the system is effectively nothing. Annually the system generates about $15,000 in the power that is sold back to Duke Energy – is actually a money making machine when offset against power purchased back from Duke Energy!
More and more states are continuing to offer incentives for renewable energy sources, and more and more energy companies are paying a premium for renewable energy purchases. Although renewable still can't compete with oil, coal, and nuclear in terms of cost of production without these incentives, eventually it will be able to compete, especially if some of the incentives in place for these other sources are taken away. For now, it's built into our current tax legislation so, if you are thinking about renewable energy anyway, consider it.
For raw land owners solar and wind, depending on the state, also represent a great way to generate income while you are waiting for the land to appreciate / be developed.
See Fox Sports Coverage - http://msn.foxsports.com/nascar/story/Martin-Truex-Jr-Racing-to-Solar-Energy-04294375).