Dennis Bushnell is the chief scientist at NASA's Langley Research Center. In this interview, he tells Susan McGinnis about the different ways that the U.S. can wean itself from oil.
Bushnell says there are an "embarrassing" number of ways the U.S. can end its oil dependence. The first way is through conservation, an aspect he believes most Americans are not serious about. He says 70 percent of all oil is used for transportation, so the goal should be to make lighter cars that use less oil. NASA is working on technology that can lighten automobiles by a factor of three to five. Other methods to conserve fuel are using more efficient diesel engines, regenerative brakes and recycling heat from auto exhaust to produce electricity.
Another method is to use cars that run on electricity or pressurized air.
The third method, which Bushnell says is the best way, is to use biofuel, which he says can produce a closed carbon dioxide cycle because they are made using CO2, and the CO2 they produce can be used to produce more biofuel. He says one efficient and still underused way to produce biofuel is to use halophytes, or salt plants, grown on irrigated desert land. He says that could produce enough biofuel material to replace not only all the oil that is currently used in the world, but all other fossil fuels and petrochemicals used to make plastics. He says they would also solve all the world's land and water use problems.
Bushnell says algae and cyanobacteria also use salt plants, waste water and wasteland, and have even larger biofuel yields than halophytes, which produce about 700-800 gallons per acre/year. He says algae is very productive but too expensive. He says recent experiments on cyanobacteria show it can produce biofuel at a lower cost.
He says British companies are selling a bioreactor, which can use sewage, kitchen scraps and yard waste to produce automobile fuel. He says this is an example of distributed production, which can allow homes to produce their own energy, independent of the electrical grid or other mainstream production.