What's the Big Deal?
The state of Illinois is launching the biggest and most aggressive procurement program for renewables in the country. This program will pay for 30% of your systems total cost. Add that to your 30% federal tax credit and you have more than ½ of your system paid for. That's 60% off the total cost of your solar array. Don't forget about Depreciation. You can now depreciate 100% of your solar system.
These kinds of savings will put you at a 6 year payback.