There are lots of options for stationary powerplants: hydro, natural gas, wind power, solar thermal, etc etc. However there are few viable solutions for the transportation industry, the most vulnerable sector in the event of an oil shortage. Supply & demand are the cornerstones of economics, and without transportation you can't have supplies. The transportation system is the backbone of our supply lines. Most cars on the road are designed to run on a single fuel only, gasoline, a fossil fuel. If gasoline ran out, our transportation system would stop, and so would our economy.

Most plants are made of up to 98 percent cellulose. Cellulose is the most abundant substance made by living things. In fact fossil fuels originally came from cellulose, but they have been rotting under the earth for millions of years. Freshly grown biomass can be converted into ethanol, a superior fuel. Ethanol burns cleaner, meaning far fewer carbon monoxide emissions, no sulfur dioxide emissions. It also burns cooler, meaning far fewer nitrogen oxide emissions, and the engine will last 2-3 times longer due to lower maintenance. Furthermore ethanol is a monochemical, and as such it is easy to tune an engine so that all the fuel is burned completely with each power stroke. In contrast, gasoline is composed of a mixture of about 40 different hydrocarbons, all of which have slightly different flash points and combustion rates, making it impossible to optimize the engine cycle -- there is always residue left over. A gasoline engine burns dirtier, hotter, produces more carbon monoxide, sulfur dioxide, nitrogen oxide, and requires more lubricants and higher maintenance over its much shorter lifetime. On top of all that, ethanol, unlike gasoline, is a renewable fuel, and a zero net emitter of greenhouse gases. Ethanol can be mixed up to 10 percent by volume with gasoline and used in regular internal combustion engines without any modifications, while at the same time displacing the same amount of gasoline consumption and eliminating the same amount of greenhouse gas emissions. Not only can ethanol be used in ordinary internal combustion engines, but since it is a pure fuel, composed of a single hydrocarbon chemical, it can be used in Direct Liquid Ethanol Fuel Cells, which produce electricity at high efficiency from ethanol in a manner similar to an electrochemical battery. Should fuel cells ever become affordable, this will be an excellent way to power more cars using a limited supply of renewable fuel. In the meantime, the use of ethanol mixed with gasoline at concentrations greater than 10 percent requires flexible fueling modifications. There are already a large number of these Flexible Fuel Vehicles on the roads, their owners no doubt unaware of their freedom to choose which fuel to purchase. People wishing to acquire one will be happy to learn that these vehicles are typically not econoboxes, but are actually full sized trucks, minivans and SUVs which have had their engines modified at the factory to run on either gasoline or ethanol, or any combination of the two, no tinkering necessary.

Ethanol comes from biomass. It can be made at home by fermenting starchy plants such as corn or jerusalem artichokes. On an industrial scale it is made by hydrolyzing biomass that is high in cellulose to produce fermentable sugars. This is done by soaking the biomass in a weak sulfuric acid solution to break the long chain fibers into glucose. Yeast is then added to ferment into ethanol. Molecular sieve distillation is performed to remove all water from the ethanol. Waste lignin from the hydrolysis process is used as boiler fuel to power the distillation step, allowing a net positive energy gain of at least 25% in the form of fuel ethanol from the entire process.

A great deal of biomass is produced by prairie farms in North America, including wheat straw, rice straw, corn leaves & stalks, cord grass, switch grass, sawdust, waste cardboard & paper, even lumber operations. Using 1/3rd of the wheat straw from the Canadian provinces of Alberta, Saskatchewan & Manitoba, Canada would be able to produce enough ethanol to displace 10 percent of all national gasoline consumption, and thereby meet its Kyoto obligations -- at least for the transportation sector. This is possible because plants are extremely efficient at utilizing sunlight to grow, converting solar energy mostly into cellulose. According to my analysis (see Starship Generations, topic #2, lighting efficiency for solar radiation and photosynthesis efficiency charts) plants utilize approximately 17.6 percent of incident solar radiation to do this, which easily competes with, and is often far in excess of, the efficiencies commonly reported for photovoltaic cells, wind power, and solar thermal powerplants.

Still, as efficient as biomass production is, it is possible that energy crops will compete with food production for land useage. In that case we may have to turn to the oceans for biomass supply. See my essay entitled Benthic Energy, found near the bottom of my Starship Generations website.