| Western Solar's Small Wind Systems Wind power is one of the oldest renewable energy technologies.
Wind has been used for centuries to pump water and grind grain. Modern
wind turbines convert wind energy into electricity. This can be one of
the most cost-effective of all renewable energy technologies. However,
wind generators are not for everyone. They require a suitable windy site
location and some maintenance for upkeep. If there is any question about
wind velocity and consistency at a site, we suggest first installing a recording
anemometer system to record daily wind speeds for at least a year. We also
recommend that anyone interested in installing a wind system first review the
articles and books cited below under "More Information".
Key Benefits
 | Wind systems can be the lowest cost renewable energy source (given a suitable
wind site) |
| Unlike photovoltaics, wind systems can generate electricity
24 hours per day |
| Can be integrated with a photovolatic system to supplement
electrical production during winter low light conditions |
| Wind Systems are eligible for a Federal Tax Credit of
$4,000.00 |
Western Solar's Wind Options
Western Solar has the ability to offer multiple wind turbine
options depending upon the specific site conditions, available wind resource,
and the customer's budget. For the majority of residential and small
commercial applications we recommend Southwest Windpower's Skystream 3.7 (see
photos above). It has a unique blade design that allows it to offset the
maximum amount of your annual electric bills with minimal average wind speeds,
while cutting through the air with one of the lowest background noise levels on
the market. When combined with the tilt-up pole design and integrated 240
VAC inverter, it is one of the finest wind turbines on the market.
How Does it Work?
Wind generators convert the winds pressure against the blades
into rotational energy which drives a small electric turbine and generates
electricity.
The power in the wind is proportional to:
| the total area being swept (determined by blade
diameter) |
| the cube of the wind speed |
| the air density - which varies with altitude |
Different wind speeds to consider are:
| Start-up wind speed - the wind speed that will turn an unloaded rotor |
| Cut-in wind speed – the wind speed at which the rotor can be loaded |
| Rated wind speed – the wind speed at which the machine is designed to run
(this is at optimum tip-speed ratio) |
| Furling wind speed – the wind speed at which the machine will be turned
out of the wind to prevent damage |
| Maximum design wind speed – the wind speed above which damage could occur
to the machine |
There are three general types of towers: guyed tilt-up (left), free standing
lattice (center) and cantilevered tubular (right). Guyed towers are
usually the most economical for small wind turbines, but do require occupy
considerable ground area for the anchored wires.
What Does it Cost?
As a rule of thumb, wind turbine systems will cost about $4000
to $6000
per installed kilowatt. This is about half the price of an equivalent photovoltaic
system. Thus, a typical 3 to 10 kilowatt residential wind system with 80
foot tower, batteries, and inverter would cost between $12,000 and $40,000.
Larger systems are generally more cost effective.
How Much Wind Do You Have?
We can provide a free estimate of the feasibility of using
wind power at your particular site based on average annual wind speed.
However, before installing a system we recommend a detailed 6 month wind analysis and
report using a wind datalogger installed onsite, which we can provide for about $1200.
More Information
Wind
Electric Systems Simplified by Ian Woofenden (Home Power Magazine Vol 110).
Small Wind Electric Systems: A Washington Consumers Guide (U.S. Department of
Energy)
Gipe, Paul. 2004. Wind Power. Chelsea Green Publishing
Company. 496 pp. ISBN 1-931498-14-8
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