As renewable energy gets cheaper and machines and buildings become more energy efficient, a number of countries that two decades ago ran on a fuel mix much like America's are successfully dialing down their fossil fuel habits. Thirteen countries got more than 30 percent of their electricity from renewable energy in 2011, according to the Paris-based International Energy Agency, and many are aiming still higher. A National Research Council report released last week concluded that the United States could halve by 2030 the oil used in cars and trucks compared with 2005 levels by improving the efficiency of gasoline-powered vehicles and by relying more on cars that use alternative power sources. Other countries have made far more concerted efforts to reduce fossil fuel use than the United States and have some impressive numbers to show for it. Of the countries that rely most heavily on renewable electricity, some, like Norway, rely on that old renewable, hydroelectric power. But others, like Denmark, Portugal and Germany, have created financial incentives to promote newer technologies like wind and solar energy. People convinced that America needs" the oil that would flow south from Canada through the Keystone XL pipeline might be surprised to learn that Canada produced 63.4 percent of its electricity from renewable sources in 2011, largely from hydropower and a bit of wind. (Maybe that is why Canada has all that oil to sell.) The United States got only 12.3 percent of its electricity from renewables in 2011.