Gratifying, if bittersweet, is news that General Motors will be producing the Chevrolet Volt II, a leap into on-board electricity generation that follows a concept that I have been promoting for more than a decade, as outlined in previous blogs. In the Volt II, a gasoline engine powers a generator which keeps a modest bank of batteries charged. They have only to take one more step.... substitute a biodiesel engine, and they will then have the first near-zero carbon footprint car.
It’s not such a new idea. Diesel electric locomotives have been in service for over a hundred years. On board power generation...a design waiting to be adapted to the automotive industry. True, Diesel-electric locomotives don’t need batteries, but that is incidental. Start-up and acceleration requirements are quite different, and in a car it is advantageous to have ability for short range commute on battery power and ability to reach the next fuel station if one runs out of “gas.” (even so, in a pinch, that bottle of olive oil in the grocery bag is really reserve fuel)
The Germans are somewhat ahead of American manufacturers. Their cars will sport biodiesel engines, and are already making an appearance.
This is not good news for all-electric cars that plug into the grid, like Leaf and Tesla. But these cars offer no reduction of carbon footprint and have limited usage in regions where storm damage leaves citizens without power for days or weeks at a time. Moreover they have a very low thermodydamic efficiency. All but two states operate coal fired power plants, providing about half the nation’s electrical power, so the odds are high that a plug-in electric car will be a coal burner.
Efficiencies of Leaf and Teslas that obtain power from coal burning power plants are under twenty-five percent, whereas a bio-diesel electric, described above, could reach forty percent.
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