Sunday, August 19, 2007

Coal Into Cars: The Good, the Bad, the Ugly

The Ugly

Coal sucks, there's really no two ways about it. Extracting it is ruinous of the landscape and burning it has disastrous environmental consequences. It should be perhaps our last fuel of choice regardless of how it's used. But not all use of coal is alike.

The Good

About half our electricity comes from coal, and that will change, at best, slowly as we move to renewables. But we need to keep in mind that when we're talking about cars, even coal-generated electricity results in lower greenhouse gas emissions compared with petroleum. The EPRI-NRDC Plug-in Hybrid Study makes clear that under every scenario studied, every region will yield reductions in greenhouse gases as we increase the number of plug-in cars. That includes the worst, most coal dependent areas. Of course as our efforts to green the grid take effect, and that's happening already, plug-in cars yield even greater reductions in GHGs. And ultimately, you can get no cleaner car than an electric car using wind or solar generated electricity.

The Bad

There is a major push at the federal level to subsidize the coal industry to produce liquid coal as a replacement for petroleum. It is touted as part of a move toward independence from foreign oil. Support knows no party. Like subsidies for ethanol, it's a regional matter. As a replacement for gasoline, there is probably no worse choice than coal-generated liquid fuel. As the Scientific American editorial "Worse Than Gasoline" states:
"...the polluting properties of coal - starting with mining and lasting long after burning - and the large amounts of energy required to liquefy it mean that liquid coal produces more than twice the global warming emissions as regular gasoline.....driving a Prius on liquid coal makes it as dirty as a Hummer on regular gasoline."

There's a lesson here we can apply to our choices regarding biofuels, too. The energy required to make biological matter into liquid fuel certainly tips the balance against ethanol, just as it does with liquid coal. However, as the Environmental Entrepreneurs report on Costa Rica recommends, biomass crops into electricity is a beneficial strategy.

We can make electricity many ways, some better than others. But in the end, there is no further pollution using the electricity, whether in iPods, toasters, light rail, or cars. If we must use coal, make electricity, don't turn it into a liquid fuel we still have to burn. If we find it advantageous to use biomass or even corn for energy, make electricity with it.

It bears repeating again and again - the worst electricity is better than petroleum. And only electricity offers us the possibility of truly zero emission transport.

It's the plug, stupid.