Wood-burning internal-combustion engines, used to power road vehicles? A sort of rudimentary “solar power?”
Fanciful though this might sound, the idea is not new and continues to attract attention as an “alternative” fuel.
Vehicles fueled by wood – more precisely, by wood gas – were used on a large scale during World War II in several European countries and Japan because of petroleum shortages. In Japan, petrol (gasoline) rationing was imposed in stages during 1938, forcing many bus operators to convert to charcoal. Petrol could not be used for any civilian transport after 1941; taxis and other non-military vehicles that remained in operation thereafter burned charcoal.
However, we did not know that lorries (trucks) fueled by wood gas are still used in North Korea:
http://www.enlight.ru/camera/dprk/village_e.html (scroll down to fourth photo, with caption beginning “Machines typical for village . . .;” we found the “Wandering Camera” web page while researching another topic). Nor did we know that China, Russia and Singapore continue to produce wood gas generators for automobiles and for industrial use.
A significant disadvantage of wood gas is its low heat content (megajoules per kilogram) relative to other fuels. “Wood gas” is actually a mixture of several gases. It is flammable because it contains methane, hydrogen and carbon monoxide; the latter accounts for the largest share of the mixture (roughly 30 percent). This is another significant disadvantage, because carbon monoxide is poisonous – and colorless, odorless and tasteless.
Absent an “energy emergency” of implausible severity, we doubt that buses fueled by wood gas will be serving your town anytime soon.
For Further Reading:
http://en.wikipedia.org/wiki/Wood_gas (Wikipedia).
http://en.wikipedia.org/wiki/Wood_gas_generator (Wikipedia).
http://laforum.org/article/baldwin-hill-park-crenshaw/ (http://laforum.org/). One of us remembers seeing large stationary gas-fueled internal-combustion engines in this area, at a natural-gas compressor station, during the early 1960s.