The US could replace all its cars and trucks with electric cars powered by wind turbines taking up less than 3 square kilometres - in theory, at least. That's the conclusion of a detailed study ranking 11 types of non-fossil fuels according to their total ecological footprint and their benefit to human health.
The study, carried out by Mark Jacobson of the atmosphere and energy programme at Stanford University, found wind power to be by far the most desirable source of energy. Biofuels from corn and plant waste came right at the bottom of the list, along with nuclear power and "clean" coal.
Watch a video of Jacobson discussing his findings.
The energy sources that Jacobson found most promising were, in descending order:
- Wind
- Concentrated solar power (mirrors heating a tower of water)
- Geothermal energy
- Tidal energy
- Solar panels
- Wave energy
- Hydroelectric dams
To compare the fuels, Jacobson calculated the impacts each would have if it alone powered the entire US fleet of cars and trucks.
He considered not just the quantities of greenhouse gases that would be emitted, but also the impact the fuels would have on the ecosystem - taking up land and polluting water, for instance. Also considered were the fuel's impact on pollution and therefore human health, the availability of necessary resources, and the energy form's reliability.
"The energy alternatives that are good are not the ones that people have been talking about the most," says Jacobson.
"Some options that have been proposed are just downright awful," he says. "Ethanol-based biofuels will actually cause more harm to human health, wildlife, water supply, and land use than current fossil fuels."
Top 7 alternative energies listed
Fri, 16 Jan 2009 15:01:00 GMT
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