What OSO RENEWABLE ENERGY can do for you…


Wind Energy

Wind power is a great source of energy in locations with adequate potential. Before you dream any further however, it takes a lot of windy days and nights to make it a reliable source of power. Average wind speeds of 10 miles per hour or 4.5 meters per second or greater are required at the location of the wind turbine. To put that into perspective, that means 7 times out of 10 your are struck by the force of the wind when you head out the door (that is if you didn’t grow-up east of the divide). 3 times out of 10 you have to lock your hat down or pull your clothes in. Another way I like to describe how much wind it takes to be a reliable source of power at your location is for you to go outside daily with a hard back book you like and try to read. If you are forced to go somewhere out of the wind to read in order to avoid tearing your pages 4 days in 5, you have a good location for wind. In good wind locations trees will look sculpted by the prevailing wind. While these are not scientifically proven methods they do help put into perspective how much wind potential you might have. 

There are instruments available used to monitor wind potential at your site. They can be a simple as a hand held observation tool used for repeated measures costing only $85 or wind data loggers costing around $1000.

Simple facts about physics and wind:

  • When winds speed doubles, the force increases by 8 times.

  • Most turbines produce 1/8th their rated output at 15 mph or 6.75 mps.

  • Most turbines produce max. power at 30 mph or 13.4 mps wind speeds

  • Multiply surface wind speed by 1.5 to get speeds at 30 feet above ground level and equates to 3 times the power.

  • Multiply surface wind speed by 2.0 to get speed at 120 feet above ground level and six times the power.

  • Due to decreases in air pressure wind force declines at a rate of 3% per thousand feet.

  • Turbines need to be located 10 meters above obstructions for 300 feet to avoid turbulence.

  • Our Southwest Windpower H80(1000 watt turbine) has to be rotating 4 times per second to even start producing measurable power. 

There are a lot of wind turbines to chose from. Some are grid-tied capable from right at the turbine and others operate with battery based systems and a dump load for those excessively windy periods. A dump load can be as simple as a hot water heater element or a baseboard type resistive load heater. Wind is often combined with solar for assured power during non-windy periods.

In a location with adequate wind resources the cost of the wind system could be less than for a similar sized harvest from solar. While wind turbines are not hugely expensive relative to their harvest potential, the tower and its installation can exceed the cost of the turbine so be wary about posted prices.

For those potential customers living in the valleys west of the Continental Divide in BC and Montana, there are few locations where wind will beat out solar for reliability and price per kWH harvested over the long run. If you have a location in an exposed saddle, or close to a ridge top then buy a wind data logger and get some good data before you spent thousands of dollars.

All this being sound and sobering advice, there are smaller less expensive wind turbines that work on a sail boat or during stormy weather. They are very enchanting and magical to watch knowing they are making even little energy.

In Cuba they employ homemade wind turbines to charge electric fences. They are recycle from old automobile wiper motors and home made wooden blades. There are service organizations that arrange trainings in 3rd world coastal villages to show the local residents how to build and maintain their own wind turbines, from recycled motors and hand made blades. This maybe be more than you want to know, but we just wanted to share how simple it can be to harness the wind.


  © 2009 Oso Renewable Energy