From an article by Nick Paulson in the Wisconsin Rapids Tribune:

For some time, Tom Klismith has followed the federal incentives to install renewable energy systems at his certified public accounting firm.

He liked the idea of installing solar panels at Klismith Accounting, but as a numbers man, the incentives — which cover 30 percent of the installation costs — just didn’t add up.

“When you did the tax return, the alternative minimum tax was negating the impact” of the federal incentives, Klismith said.

But when that tax law was changed as part of the American Recovery and Reinvestment Act of 2009, Klismith pounced. He had 112 solar panels installed at Klismith Accounting. In the two months since he installed the panels, Klismith has saved $425, but he expects that number to rise as the days grow longer and there is more sun. During the course of the year, he expects to save at least $6,000.

At that rate, the system should pay for itself in less than 10 years. That means big savings for the company because the equipment will last 20 to 25 years.