The Answer Is Plug-In Hybrid Electric Vehicles

Whether the question is how to reduce our dependence on foreign oil, how to save money spent on transportation, how to reduce CO2 emissions much more quickly than anyone thought possible, or how to accommodate the transportation demands of the fast-developing developing world, the answer is Plug-In Hybrid Electric Vehicles (PHEV). They’re almost too good to be true; and, in fact, they don’t exist commercially at the moment.

However, late this year Chinese manufacturer BYD plans to start selling its PHEV by the end of 2008; a plug-in Toyota Prius and Chevy’s Volt are scheduled for 2010.

Here’s the trick: theses plug-ins can only go about forty to sixty miles between rechargings. However, the average length of a car trip in the US is less than 10 miles so easily accomplished by even a partially charged car. Sure, we all take long trips at least occasionally; and sometimes we plan a short trip and end up going much further. Not to worry: remember, these are hybrids; they do have gas tanks. Once the battery runs down, the gasoline engine starts up to power the generator as in a conventional hybrid. You keep going; it just costs more per mile than when you’re all-electric but still less than today’s non-hybrid cars.

With current battery technology, the initial cost of an all-electric car with reasonable range for ordinary use is still prohibitive. That’s why these plug-in hybrids are such a good solution. The Chevy Volt is expected to cost about $35,000 and have the pickup and range we are used to in conventional cars.

The Electric Power Research Institute (funded by power companies mainly) and the National Resources Defense Council (funded by green types, mostly) did a joint study which comes out for very favorable for PHEVs. They say that, even if all the electricity for PHEVs came from coal-fired power plants (the dirtiest way to get electricity in terms of CO2 emissions), there’s still a net reduction in GHG (greenhouse gas) if we switch from inefficient gasoline to more efficient electricity for most of our driving.

In real life that wouldn’t happen. PHEVs presumably get recharged mostly at night; a high greater percentage of our night time electricity comes from hydro and nuclear since total demand is much less then. Moreover, we have lots of options including nuclear, wind, solar, and carbon-sequestration at coal plants for increasing electric power generation while decreasing emissions. Notice that most of these sources are domestic!

An article in Harvard Magazine by Michael B. McElroy commenting on the EPRI study says:

“Replacing 90 percent of gasoline consumption by electricity would be equivalent to raising the fleet’s average fuel efficiency from the present level of about 17 miles per gallon to close to 150 miles per gallon. Were we to accomplish this objective, total oil use would be reduced by 36 percent, cutting the demand for imported oil by as much as 60 percent (a savings of $270 billion per year at current prices for oil). ...”

40% of oil use in the US is to power cars and light trucks, obviously a good target for reduction. No way we’re going to replace a substantial part of this with corny ethanol nor should we try. The Harvard article suggests that, even if (or maybe when) biofuels are developed which don’t compete with food, it’d still be more efficient just to burn them (or the plants they come from) in electric generating facilities than to take all the extra steps needed to make them into transportation fuel.

The operating economics are already right thanks to the rising cost of oil. A gallon of gas is the transportation equivalent of 7.5 kWh of electricity. That mean that even at a pretty high rate of $.20/kWh, using electricity is the equivalent of paying $1.50/gallon. Better yet, it’s reasonable to assume that off-peak electricity can be purchased more cheaply and that there is a per unit savings in MORE use of the electric grid and power plants at night. So that price might at least stay reasonably stable even with escalating demand.

The proof should be in the pudding soon. There is no new technology required although there are some engineering problems: Chevy reports trouble getting the electrical budget of things like in car entertainment, air conditioning, and even windshield wipers down far enough to keep the all-electric range of the Volt high enough. Assuming charging mainly at night, we don’t need to rebuild the electrical grid right away (although we should). We don’t need massive new generating capacity; we just run what we have more hours (but we should be building).

This energy stuff really is more an opportunity than a crisis.