2. The solar panels are expected to last about 25 years. But Yamauchi knows the inverters, which convert direct current to alternating current, will have to be replaced before then, in 10 years to 15 years.

The need to replace inverters is "kind of the weak point in the system," Yamauchi said. The average replacement cost of an inverter is about 5 percent to 8 percent of the total cost of the solar system, according to one inverter maker that asked not to be named.

3. Maintenance costs are low. The panels are on the roof and occupy about 54,000 square feet. In the four years that the panels have been used, they have been washed four times, Yamauchi said.

4. Solar power doesn't raise specific IT issues. "It just augments the grid power for us," said Yamauchi.

But solar power is not an uninterruptible power supply, he said. As with most solar systems, it's attached to the electric grid, and if the grid goes down, so do the solar systems. There's a safety reason for that, he said, to protect linemen from electricity being generated by the system.