Top 7 alternative energies listed

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

Technorati Tags: alternative energy,photovoltaic,wind power,tidal,geothermal,hydroelectric,ocean power

using eddy currents/vorticies to generate power in fluids/gases

Much like new fangled performance swim suits take advantage of strategically placed bumps to facilitate faster swimming, there's been some improvement related to fluid dynamics and power production.

This article points out the basics of the technology, which is under development in Michael Bernitsas' lab at the University of Michigan.

Clean Power Tapped From Swirling Currents
Emily Sohn, Discovery News

Dec. 15, 2008 -- Currents can be powerful enough to tip canoes, damage docks and even topple bridges. The force of all that moving water can also provide a clean, affordable and unobtrusive source of renewable energy, says engineer Michael Bernitsas, of the University of Michigan in Ann Arbor.

Bernitsas has invented a device, named VIVACE, that converts river and ocean currents into electricity. Like fish, the device takes advantage of powerful phenomena called vortex-induced vibrations.

These vibrations occur when water flows past a round or cylindrical object. Swirls of water form downstream from the object and in an alternating pattern on either side of it. That causes the object to oscillate, or vibrate, up and down.

Vortex-induced vibrations also occur in air. And they have been responsible for some high-profile disasters, including the 1940 collapse of the Tacoma Narrows Bridge in Washington.

(you'll have to follow the link for the rest of the article)

VIVACE - Vortex Induced Vibrations for Aquatic Clean Energy

Very cool:

Technorati Tags: VIVACE,ocean power,renewable energy