Norwegian scientists have drawn up a league table of alternative fuels for cars based on what they call a "well-to-wheel" analysis. Their approach takes into account the energy costs in manufacturing, total energy use, and overall pollution included greenhouse gas emissions. Unsurprisingly, petrol and diesel vehicles foot the table, closely followed by hybrid vehicles. In contrast, the greenest way to power a vehicle turns out to be to use an electric fuel cell powered by hydrogen made from natural gas, methane. "It must be emphasized that no single chain comes out with the best score on all impact categories," the researchers say, "There are always some sorts of trade offs involved. Thus, there are no obvious winners; only good or bad trade offs between different impact categories."
Well to wheel analysis