General Motors building world's largest rooftop solar power array

While the irony of harnessing solar power to build gas guzzling cars is hard to ignore, GM has become a world leader in the use of solar energy to power their factories. Now they have announced plans to install the world's largest rooftop solar array at their massive Zaragoza plant in northern Spain.

When completed at the end of September, the 85,000 panel system will cover about 2 million square feet of the roof to deliver 10 million watts, or enough to power around 4,600 households. That should be plenty to take care of the plant's energy needs, with any excess capacity being sold back to the local power company.

Let's just hope they plan to keep the green theme going by using the plant to build some of those sexy electric Chevy Volts.