Metro de Bilbao, the company that oversees the subway system for the city of Bilbao, Spain, has announced that all of the energy the system used last year was obtained from renewable sources, according to AutoblogGreen, adding that it's a first for a citywide subway anywhere in the world.

The company said in a statement that Naturgas, a local utility, supplied the renewable energy--and helped the system save 46,000 metric tons of carbon dioxide from being released into the atmosphere in 2008. That's equivalent to taking 8,000 cars off the road, assuming each one was driven for 20,000 miles per year.

In addition, the company announced that all cars now have a new brake energy recovery system that provides better braking performance and helps reduce energy consumption by up to 33 percent, according to the report.