Despite Toyota's interest in solar power, it has not been adopted to any extent by IT managers as an alternative source.

Ken Brill, founder and executive director of The Uptime Institute Inc., a consultancy in Santa Fe, N.M., said the efficiency of solar systems is still low, and the cost is high and requires subsidies. "Things should make economic sense, and the private market will take care of it," he said.

Moreover, solar systems aren't resistant to hurricanes and other weather-related problems and their panels take up large amounts of space, Brill said. "It's not just the cost -- to me it's also the real estate" they need.