Wind Energy Products Washington DC
How to Harness the Wind
Mankind has been harnessing the wind since learning to sail the Nile River thousands of years ago. From old Holland to the old American West, wind has been used for centuries to pump water, grind grain and sail the seas. Today, wind turbines are becoming an increasingly popular way to capture wind's power to generate electricity for our homes. Wind is a free renewable resource and is environmentally sound. It cushions the blow of volatile energy costs and can reduce utility bills - sometimes by more than 90 percent.
Buying and installing a wind turbine for your home can be expensive on the front end, and the economics of a wind system depend on the average winds and the cost of electricity in your area. But state-rebate and tax-credit programs passed in the last few years have made wind a more affordable and attractive option for many homeowners. Wind-turbine manufacturers say that as technology improves and the government uses more incentives to encourage the use of wind power, it is only a matter of time before more homeowners jump on the wind-energy bandwagon. Mike Bergey, president and chief executive of Bergey Windpower Co. in Norman, Okla., says there are probably 5,000 or so "grid-connected" home wind-power systems in the United States that are connected to electricity transmission systems. There are another 8,000 to 10,000 stand-alone hybrid wind-solar power systems for homes that are not connected to power grids, he says. A grid-connected wind turbine, which is the most common home wind system for people linked to power grids, can reduce consumption of utility-supplied electricity for lighting, appliances and other everyday needs. If the turbine can't produce the energy you need at certain times because the wind isn't blowing, the utility will make up the difference. When the wind produces more power than you need, the excess can be sold back to the utility. Stand-alone systems are more common for homes that are far from the nearest utility lines, where it is cost-prohibitive to tie into the lines, or for people who want total energy independence.
People with stand-alone systems recognize the intermittent nature of wind power and usually use other resources - such as solar - along with wind to meet their power needs. Wind power certainly isn't for everyone. But a grid-connected system might be appropriate for you if your electricity costs are more than 10 cents per kilowatt-hour and winds in your area average more than 10 mph, according to the federal Department of Energy. There are other considerations as well when deliberating whether to install a wind turbine. Homeowners must make sure that local zoning and permitting laws allow wind turbines and that they own at least an acre of property - a tower that rises 100 feet or more generally is not appropriate on smaller lots in densely populated neighborhoods.
Additionally, you should be comfortable with making a large investment that might not pay itself back for 10 to 20 years, depending on the wind economics of your area and your states' rebate and tax-credit laws. If you pay low utility prices, don't have enough wind or live on a small lot, then wind-turbine systems probably aren't right for you. To determine your electrical costs, look at your utility bill. If you aren't sure about the average wind speeds in your area, the Department of Energy has wind maps that can help. The maps provide a starting point, but you might want to use an anemometer over a year to get exact wind-speed measurements at your home. You also should consider local conditions, such as whether you live on the sheltered side of a hill.
But if wind power is appropriate, then wind turbines offer a way to cut utility costs by 50 to 90 percent without polluting the air. The American Wind Energy Association estimates that a small residential wind turbine can offset 1.2 tons of air pollutants and 200 tons of greenhouse gases over its lifetime. Bergey says Americans clearly like the concept of using wind for power. In a Gallup poll last year, 91 percent of the respondents said they support increased use of renewable resources, such as wind and solar power. Besides, Bergey adds, "Who wouldn't want to a have a $5-a-month utility bill?" There is certainly nothing new about converting wind into power. There is evidence that wind was used to propel boats on the Nile River as far back as 7,000 years ago. Simple windmills were used to pump water in China several centuries before Christ. In the United States, millions of windmills were erected as the American West was settled in the late 19th century, mostly to pump water for farms and ranches.
Today, the use of wind power is growing fast. The installed capacity of wind power in the United States, according to the Department of Energy, rose from 2,554 megawatts in 2000 to 4,258 MW in 2001, an increase of 40 percent. Granted, nearly all of that power comes from wind farms, where turbines are grouped together to generate bulk electrical power that is fed into local utility grids and distributed to customers just like conventional power plants. But with electricity supplies increasingly unpredictable - who can forget the recent brownouts and crazy prices in California? - turbine manufacturers say interest is growing in wind power at the homeowner level. Bergey says an estimated 500 to 1,000 such systems are installed each year and that the residential wind-turbine industry is growing about 35 percent a year in revenues. A home grid-connected wind-turbine system typically includes a rotor with blades and a generator atop a steel tower that might be 60 to 120 feet high.
The rotors are wired into the home's circuit breaker so homes are served simultaneously by both the wind turbine and the utility. (Stand-alone systems are generally smaller and generate less electricity.) That way, the house still gets power from the utility when winds die down or consumption exceeds the turbine's power generation - such as in the summer when consumption goes up in hot climates because of air conditioning. However, if the utility's power goes out, the wind turbine does not provide a backup unless you have battery packs to store the power in reserve. Federal regulations (the Public Utility Regulatory Policy Act of 1978, or PURPA) require utilities to hook up to small wind systems and to buy back excess power generation from those systems.
When winds are moderate, you will buy a portion of your power from the utility and your power meter will run slowly. When the power generated by a wind turbine is exactly the same as the amount of power being consumed, then the utility meter stands still. And when the power being generated by a turbine exceeds the energy consumption inside a house, the meter can actually run in reverse. "A lot of people say, "Gee, it's nice to see the electric meter run backwards,'" says Tom Gray of the American Wind Energy Association. Of course, there are drawbacks to wind-turbine systems. The No. 1 downside is the high initial cost. Manufacturers say a 10-kW system - the size needed to provide the power needs of a typical home - will cost $30,000 to $40,000 installed.
If you have a $200-a-month utility bill and the turbine saves you 75 percent of that, the payback can be 20 years. If you have a $300 monthly utility bill and a turbine saves you 75 percent, then the payback will be closer to 12 to 14 years. The payback time will be shorter if you live in a state that offers rebates or tax credits. California, for instance, gives a 50 percent rebate to turbine buyers, making the payback a decade or less, depending on the wind speeds and the cost of electricity. After the turbine is paid for, the electricity is virtually free and it's not unheard of for wind-turbine owners to get electric bills for the monthly minimums of $10 or so a month. Homeowners often have to overcome neighbors' objections to having a 100-foot tower in their yard, which is why experts agree that a lot of at least an acre is necessary to make it feasible. Remember: Higher towers generally yield more wind power. "It's not so much the look of the turbine, it's anything that's tall," Bergey says.
Wind-system owners also need to check on local zoning and permitting laws to make sure that the turbines are allowed. Often, towns have height restrictions of 30 or 35 feet, meaning homeowners would have to get a variance to install a 100-foot tower. Noise has posed a problem in the past, but the machines of today are much quieter than turbines of years past. Manufacturers say turbines nowadays are as quiet as residential air conditioners and can't even be heard 100 to 200 feet away. Conservation groups are also concerned about the hazards of wind turbines to birds. Most bird deaths, however, have come at large wind farms - not single residential wind turbines. The Department of Energy says smokestacks, radio and television towers, and even pollution kill far more birds than wind turbines.
"They are far less threatening to birds than a plate-glass window," Bergey said. Bergey says U.S. sales of wind turbines were virtually dead from the mid-1980s until the late '90s. But sales have steadily climbed the past few years, he says, largely because a growing number of states now have rebate programs or tax credits for wind-turbine purchases. He says federal incentive programs would help sales even more. These days, California, Illinois, Rhode Island, Connecticut and New Jersey offer state rebates to homeowners who buy wind-turbine systems. North Carolina and Montana have tax credits. Consumers are also influenced by the price of power. Steve Turek, general manager of Wind Turbine Industries in Prior Lake, Minn., says his company usually sells a dozen or so turbines a year - until electricity prices heat up, that is. Then it might sell 25 to 50 a year. Experts say more consumers will turn to wind for their home energy needs in the years ahead if prices fall. That will probably take more government incentives and somebody willing to mass-produce the turbines. "I think there will be significant demand if prices can be reduced," Gray says. "The machines are pretty competitive even as they stand, but you need to get the payback down so more homeowners would be attracted."