Sunday, October 7, 2007

Catching the Wind

Electric Cars will become more of a reality when battery technology allows the storage of enough energy to give electric cars suitable range for the average commuter while not taking up a disproportional share of the storage space or adding undue weight. Overcoming these hurdles will attract mainstream consumers.

The other challenge is developing means to generate and transport the electricity to the home and workplace for charging at a lower cost and with greater efficiency. Otherwise, you are just transferring the emissions and dependency on non-renewable energy sources upstream to the power plant, most of which currently burn coal, natural gas and oil, at least in the US. Then, much of the energy, up to 30%, is lost in transmission. As such, our dependence on fossil and foreign fuel sources, not to mention environmental concerns will not be resolved.

Generating electricity in a renewable way may hold the great promise for generating electricity on more cheaply. The Midwest, being a frontal climate, has no shortage of wind.

A group of Midwest utilities is building a plant that will store excess wind power underground The future is taking shape under the windswept corn and soybean fields outside Dallas Center, Iowa. At the Iowa Stored Energy Park, a coalition of local utilities is grappling with one of the thorniest challenges in the field of renewable power: how to store the excess energy windmills create when demand is low so it can be used later, when the need is greater.

The group is building a system that will steer surplus electricity generated by a nearby wind farm to a big air compressor (diagram). Connected to a deep well, the compressor pumps air into layers of sandstone. Some 3,000 feet down and sealed from above by dense shale, the porous sandstone acts like a giant balloon. Later, when demand for power rises, this flow is reversed.

Backed by funding from the Energy Dept., more than 100 municipal utilities in Iowa, Minnesota, and the Dakotas are ponying up a total of $200 million to build the 268-megawatt system. Begun in 2003, the project is on track to go online in 2011.

Despite being unpredictable, wind is the nation's fastest-growing form of renewable energy. In the past five years output from wind farms has grown tenfold, to more than 12,000 megawatts, or about 1% of total U.S. supply. Its fans predict that someday wind could supply 10% or more of the nation's electricity. That's already the case in Spain and Denmark.

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