These landfill emissions consist largely of methane, which ton for ton can do even more damage to the climate than carbon dioxide does. So not only are landfills relatively competitive sources of electricity, but siphoning off the methane prevents one of the worst global warming gases from getting into the atmosphere. In addition, there are new sources of wind power being constructed in Pennsylvania, in order to add this clean source to the supply mix. Natural gas is a cleaner source of power generation than other fossil fuels, so increasingly we're trying to move in that direction as well. In fact, at the moment, the biggest new source of power in the United States is natural gas-fired generation.
Natural gas is the cleanest of the fossil fuels.
We've worked in the Department of Energy with industry for years to develop highly efficient turbine generators that can extract a large percentage of the energy in a unit of natural gas and put out very little pollution. One of the things we are doing in the Department of Energy is to develop much cleaner, more efficient coal-burning technologies, so that when new plants get built that are based on coal, we put in the cleanest, most efficient plants available. There will be for the foreseeable future quite a mix of technologies generating power in the world. We want to be sure that while we transition to renewable energy sources we are using the cleanest of the clean traditional technologies that we can, and that we continue to improve them. There are many exciting things going on in the transportation sector.