Small Wind Systems

Wind generated electricity is the fastest growing segment of the renewable energy industry. Large “utility scale” wind power in the right location can produce electricity for lower cost than new coal or natural gas powerplants. 

In the San Juan Islands wind power works best when considered part of a hybrid PV/wind power system. Wind and PV can be a nice compliment to each other because we tend to get the windy weather during the darker half of the year. For year round off-grid living a wind turbine can provide a very welcome charge for your batteries during dark and stormy winter days and nights.  

The power potential of a wind generator is directly related to the “swept area” of the rotor blades. Residential scale wind power systems use turbines with rotor diameters between four and forty feet. Power ratings are determined using a “rated windspeed” that is usually between 20 and 25 mph. It is important to realize that the turbine will only produce its rated power when the wind is blowing equal to or above the rated windspeed. Turbines also have a “cut-in windspeed” when they start producing power in low winds and a “survival windspeed”, which is often not really known until it is too late.

Wind turbines need laminar air flowing past them without turbulence created by trees and other obstructions at similar height in their vicinity. A general rule of thumb is to place the turbine at least 30 feet above anything that is within a 300 foot radius of the tower. There are different types of towers including freestanding (lattice or monopole), tilt-up and guyed lattice. For small turbines tree mounting is possible.  

Grid-tied wind power equipment and technology have improved greatly in the last few years. Direct grid-tied wind power systems use no batteries and are always synchronized to the AC utility grid. A two-pole breaker in your main electrical panel is the point of entry for wind generated electricity to flow into your home's electrical system. If you are generating more than is being used, the power will spin your meter backwards as it flows towards a load somewhere in the utility grid. Grid-interactive wind power systems include batteries and battery-based inverters to provide a continuous source of power during utility outages and grid failures.  

Please contact us for more information on wind power systems.

Other Web Resources:

homepower.com’s WindPowerBasics.pdf