Fuel cell of pollution (other than ) for every 1,000 kW·h produced, compared to 25 pounds of pollutants generated by conventional combustion systems. Fuel Cells also produce 97% less nitrogen oxide emissions than conventional coal-fired power plants. One such pilot program is operating on Stuart Island in Washington State. There the Stuart Island Energy Initiative has built a complete, closed-loop system: Solar panels power an electrolyzer, which makes hydrogen. The hydrogen is stored in a tank at , and runs a ReliOn fuel cell to provide full electric back-up to the off-the-grid residence. Another closed system loop was unveiled in late 2011
Ethanol fuel by country the largest and most successful bio-fuel programs in the world, involving production of ethanol fuel from sugarcane, and it is considered to have the world's first sustainable biofuels economy. In 2006 Brazilian ethanol provided 18% of the country's road transport sector fuel consumption needs, and by April 2008, more than 50% of fuel consumption for the gasoline market. As a result of the increasing use of ethanol, together with the exploitation of domestic deep water oil sources, Brazil reached in 2006 a volumetric self-sufficiency in oil supply, but is not effectively self-sufficient, since most of its locally extracted oil is