Brian's Brain

This blog post references my feature article 'Cutting the Carbon Cord: Is the Answer Blowing In the Wind?' in EDN's December 15, 2006 edition.

Modern large-scale wind turbines, manufactured by companies like General Electric and implemented by private and public power utilities, are massive in size and cost. According to Wikipedia, "typical wind turbines have diameters of 40 to 90 meters and are rated between 500 kW and 2 MW. Currently (2005) the most powerful turbine is rated at 6 MW." Clearly, a wind turbine this big is not something you'd want to put in your backyard; not only would your neighbors armed with CC&R regulations have something to say about it, the FAA might also complain.

Fortunately, smaller-scale and –cost turbines are also available. One promising candidate, highlighted in the October issue of IEEE Spectrum, comes from a Flagstaff, AZ company called Southwest Windpower, which is partially funded by the U.S. Department of Energy's Wind Energy program and uses the resources of the Boulder, CO-based National Renewable Energy Laboratory Wind Technology Center. Quotes from the IEEE Spectrum piece paint a rosy picture of the startup's SkyStream 3.7 wind turbine:

• "The tiny power plant sells for US $5100; total cost including installation runs between $8500 and $11,000."
• "It can trim home electricity bills by 20 to 90 percent, depending on wind velocities, electricity prices, and government incentives in your area."
• "Southwest Wind Power estimates that a SkyStream unit will produce about 100,000 kWh of power during its 20-year design life. 'Divide, say, $9000 by 100,000 kilowatt-hours, and you end up with [an average energy cost of] 9 cents per kilowatt-hour,' says Andrew Kruse, Southwest Windpower's cofounder and vice president of business development."
• "Although, generally speaking, larger turbines are more efficient at turning the kinetic energy of wind into electrical energy, SkyStream out-performs 50- to 100-kW machines in terms of average cost of energy. Many still come in at 20 cents per kilowatt-hour or more, far above the DOE target of 10 to 15 cents per kilowatt-hour."
• "Historically, small wind rotors have been 30 to 35 percent efficient. SkyStream comes in at around 41 percent, which is close to the efficiencies achieved by large wind turbines putting out megawatts."
• "The sales potential of SkyStream is promising, says the company. 'According to the U.S. Census Bureau, there are 17 million homes in America that we believe are appropriate for a small wind system,' says Kruse. That number represents the households on a piece of property of a half acre or more in an area that has an average wind speed of 5.4 meters per second or greater."

As the Slashdot debate on the article made clear, SkyStream's 17 million potential-customer estimate is likely overstated, once potential customers' (and their neighbors') aesthetic objections are factored in. The cost benefit of wind power is also more complicated than a simple equipment-price-divided-by-power-output-over-useful-life calculation might suggest.

Consider, for example, how you might otherwise invest the substantial $8500 to $11,000 upfront cost you'd spend on a SkyStream, and what the return on that investment might be over a SkyStream's claimed 20-year useable life. On the other side of the coin, realize that once a SkyStream's cost is 'sunk', its power output is effectively 'free' (discounting maintenance costs); future power costs from fossil fuel sources are not free, are un-predictable and, if Peak Oil pundits are right, will increase over the same 20-year timeframe. Wind power prices look even more attractive once the indirect costs of fossil fuel counterparts are factored in; pollution-created medical expenses, greenhouse gas-created global warming effects, etc. And, as vehicles such as the popular Toyota Prius demonstrate, plenty of folks are willing to vote 'green' with their wallets even if their spreadsheet analyses don't validate the decision.

Another wildcard is private utility and government (local, state and federal) financial assistance. Although wind power detractors point to the technology's existing 1.9 cent-per-kWh tax credit as an artificial 'boost' to its comparative cost appeal, other power schemes (among them fossil fuel and nuclear) also receive substantial amounts of direct and indirect government subsidy. And finally, as the main article discusses, a SkyStream turbine's output is highly dependent on its location and height, along with the variability and profile of wind direction and intensity. Still, Southwest Windpower's achievement is commendable and, as the IEEE Spectrum article points out, "as the market takes off, SkyStream's price will likely fall."