Tuesday, April 24, 2007

What Type of Green Will Your Car Be?

Will you be driving a super-clean, green, hydrogen-powered fuel cell car in the future? Or a lithium-ion battery powered electric car? What about a low-emission bio-diesel? Perhaps an efficient compressed natural gas auto? Or maybe something else (hopefully, not a gasoline powered Hummer!).

Last week, we previewed the future of the robo-car--and any of the vehicles we discuss here could also be a robo model sometime down the road. This week, we'll turn to the shade of green you may be driving.


The May edition of Popular Science has an interesting feature in which they handicap the pros and cons of the automotive fuels of the future, predicting the market share each will have twenty years from now, in 2027.


It's a pretty realistic look at the future, although one hopes the timetable can be sped up through some good government policies.


The clear winner in the PopSci sweepstakes is battery propelled vehicles, including hybrids, which obviously are already on the road and making gains. While current hybrids can achieve gas mileage of 45-50 mpg, we can expect to start seeing mass-market plug-in electrics by around 2011, which offer the promise of as much as 100 mpg (of gasoline--you also have to use electricity to charge them). PopSci forecasts a 30% market share for electrics by 2027.


That's some decent news, but of course if all we do is build a bunch of coal-fired generating plants to charge up all those new electric vehicles, we won't make much progress on reducing carbon emissions. (We will, however, be more energy "independent", unless we start importing Chinese coal.)


So what of those fantastic hydrogen fuel cell vehicles that emit only water as their exhaust? The news ain't so good. PopSci forecasts only 2% market share for such cars by 2027. Technological hurdles abound--not only is fuel-cell technology not quite ready for prime-time, but it is very difficult to store and transport hydrogen efficiently, and the needed infrastructure is a long-way off. Also, the current methods for making hydrogen involve using carbon-based fuels, especially natural gas. Hydrogen can be made from water with electricity--that hydrolysis experiment you did in high school--but we'd need a lot of electricity, so once again we're looking at whether we can quickly boost renewable production of all those needed megawatts. Nonetheless, hydrogen fuel cells look like the technology of our grandchildren, something we can look forward to on trips out of the nursing home.


PopSci doesn't see any other technology making a big breakout, either. They put biodiesel at a 4% market share in 2027, with compressed natural gas (CNG) at 3%, and ethanol at 6%. (We think CNG could develop a niche for larger vehicles--trucks and buses--which would make its overall contribution to lower carbon emissions greater.)


PopSci does see big inroads for regular diesel, taking as much as 20% of the market by 2027. So what, you say? Well, modern diesel engines do emit about a third less carbon than a typical gasoline-powered car, getting 20-40% better mileage. That's some progress, but we'd frankly hope to do a lot better in the next 20 years. Also, putting in a diesel infrastructure is the first step toward more bio-diesel use.


What does all this mean? It means we have a long way to go. PopSci's estimates are probably quite realistic--it takes a long time to replace the whole vehicle fleet, and apart from hybrids and diesels, most of these technologies are barely available today. It means in 20 years we'll still be spewing vast amounts of carbon into the atmosphere from transportation, and we'll still be pretty dependent on unstable mid-east regimes for fuel.


The best way to speed up the transition is to raise the price of oil, coal and other carbon emitting fuels. The faster the price goes up, the faster our transition, within reason. If the price goes up too fast, however, it will simply harm the economy, especially the poor. What we need is a steady increase, big enough to be noticed. However, we shouldn't simply wait for demand from China and India to drive up our prices. Either a cap and trade system or a carbon tax will raise fuel prices.


It's time to get going!

1 comment:

Dan said...

You are right that we need a steady increase in the price of carbon to speed up the transition. A carbon tax, with a steadily increasing trajectory in prices as recommended by the Carbon Tax Center, www. carbontax.org, will do that. A cap-and-trade, by contrast, would not provide a steady price increase because it would inevitably result in volatile prices. With the supply of allowances limited by a cap, unusually hot or cold weather and resulting impacts on energy use would lead to spikes or precipitous drops in carbon allowance prices. That's been the experience in Europe as well as here with other cap-and-trade systems.
We need a steady increase in the price of carbon as soon as possible, not only to encourage clean cars, but also to provide an economic incentive for solar, wind and biomass to replace dirty coal plants. A revenue neutral carbon tax, combined with progressive tax-shifting as set forth by the Carbon Tax Center will be good for the environment, good for the economy and good for national security.