In an effort to jumpstart adoption of fuel cell electric vehicles, Toyota Motors earlier this month made more than 5,600 patents available to other carmakers. A few days later, General Motors introduced the electric Bolt, an electric vehicle designed to run 200 miles on batteries. Automakers, meanwhile, continue to develop yet other types of electric vehicles: plug-in hybrids and hybrid electrics. Electric vehicles are the most promising alternative to conventional gasoline and diesel-powered cars. But how is each technology different? And what are the relative benefits and commercial challenges to each?