Rooftop wind turbines offer a relatively inexpensive way to participate in the rush to renewable energy. The principle allure is low installation cost. Typically, tower installations for larger turbines add 50-80% to the cost of the system. With a rooftop turbine, an $800 tower is replaced by a $39 roof mounted tripod, or a length of pipe attached to the side of the house.
According to Ron Stimmel of the American Wind Energy Association, “…rooftop turbines still account for only 1 percent or so of the 10,000 small wind turbines that are sold each year in the country.” For this reason, few performance statistics are available from actual owners.
It’s possible, however, to get an idea of the estimated power output of a rooftop turbine from the manufacturer’s website. For example, the Energy Performance chart for Southwest Wind power’s 200W Air Breeze predicts 20-30 kWh (kilowatt hours) per month from 10-12 mph winds occurring 6 hours per day.
To put this in perspective, 30 kWh is less than 5% of the power consumed each month by the average household. Overall, the payback from a single, roof mounted turbine in tangible financial terms leaves a lot to be desired; especially in light of the fact that unlike solar, there is no Federal tax credit for residential wind power.
But anyone thinking about installing a rooftop turbine(s) is probably aware of this already. The rooftop wind enthusiast is not motivated by financial relief, but rather the intangible rewards of pride of ownership, walking the walk, or simple satisfaction as a hobbyist.
Motivation aside, it doesn’t make sense on any level to proceed with a wind powered project unless the three following requirements are met:
1. Higher than average cost per kWh. The more you pay per kWh for electricity, the more economical wind power becomes. A rule of thumb in the wind turbine industry states a residential wind powered system shouldn’t be considered unless you pay $0.10 or more per kWh for electricity.
The easiest way to determine your cost per kWh is divide the current monthly balance on your electric bill by kWh usage (also plainly stated on your bill).
2. Building codes. Visit your building department to find out if there are any zoning restrictions for roof top turbines. Don’t build your rooftop system first and ask questions later – only to be told it violates zoning laws and must come down.
3. Minimum wind speed. Wind speed of 7 mph, or 3 m/s (meters per second) is the start up speed for just about every wind turbine. However, in order to get any “juice” out of the turbine, minimum wind speeds of 10-12 mph for 6 hours per day are necessary.
Although wind speed charts for the United States and Canada are available to help site larger turbines, they’re of little use for rooftop systems because the data is collected at a minimum altitude of 30 meters (98.4 feet).
However, you can get a good idea of the wind speed at proposed turbine locations by purchasing an anemometer (wind speed meter) for around $150. The kit comes with a rooftop sensor, 60′ of cable and mounting hardware for the read out display. These are not data logging meters, so you’ll have to keep notes on your observations.
If you’re really serious about wind speed data collection, you can purchase a data logging anemometer kit with tracking software for $400.
Depending on where you live, wind speeds generally fluctuate with the seasons. Readings taken during the hot summer months of July and August, when you’re begging for a breeze, are not usually a reliable indicator of average yearly wind speed.
Also, rooftop turbines located at the edge of a long flat roof experience much more wind than those located on roof peaks.
If, after a month or two of collecting data you determine there just isn’t enough wind for a rooftop wind turbine, you can always resell the anemometer and turn your attention towards solar.
Global warming is popular topic of conversation worldwide and as people become more educated about it they are realizing the value of large wind turbines as an alternative and renewable source of energy. To the delight of many, it is not just the average joe who has come to this realization. Many community leaders have decided to make the switch to turbines as a new energy source. This is not just small communities either; large cities are also making the switch.
Beaver County, CA Getting a Wind Farm Soon
A good example of this can be found in Beaver County, CA. They are developing a renewable energy project which they have allocated about $400 million to complete. This money will pay for 150 new turbines which will provide an alternative source of power for about 250,000 homes in Southern California. This alternative power source will also allow the homeowner to see a significant reduction in their monthly energy bill. Each turbine is large enough to create about 300 megawatts of power. Standing 200 feet tall, and with blades that measure 300 feet in diameter, the entire project will span about 40 square miles of both private and public land.
As with all construction projects, there will be jobs generated by this project. During the time that the wind turbines are being built, approximately 30 days, 220 new jobs will be created. After the turbines are constructed, there will also be additional jobs created to operate and maintain the turbines and the farm. This information is per First Wind LLC, based in San Diego; they are the company responsible for originating the program. Adding to that, officials also feel that the new wind farm will generate increased revenue in the area serviced by the wind farm and, therefore, a great boost to the economy.
UK the Home of Largest Turbines
Every day we see the announcement or development of new technology all around the world. The UK is always right in the midst of any new technological developments. This includes those involving wind turbines. Wind turbines can already be found all over the countryside in the UK, but there is a project underway to develop 65 of the largest turbines yet in the town of Powys. Capable of producing 190 megawatts of power for 100,000 homes, the blades for these turbines will measure 450 feet in length.
Another benefit of the turbines is that they are expected to create quite a stir in the tourism industry. Not only will the once quiet area of Powys suddenly find themselves dealing with tourists who wish to see the turbines that have outdone the size of the ones in Wales, but it is estimated that the turbine farm will be visible from Snowdonia National Park and from the peak of Cadair Idris, making it a potential landmark on the mainland.
The Value of Building Farms
Wind farms have many benefits, including a boost to the tourism industry in the area, improvements to the economy in the area of the farm, and the generation of new jobs. The biggest benefit, however, is often one of the most overlooked. It is the benefits that are provided to the natural wildlife habitat in the vicinity of the farm. After the turbines are constructed, wildlife habitats are being built or improved in an attempt to secure the success of the animals and the ecosystem native to that particular area.