Small Wind

Many people get a great deal of satisfaction from generating their own power from wind, creating a sense of independance from their utility.

Erecting a small wind turbine at your home or business can be a great way to do this. The economics of small wind vary greatly, depending on wind resource. Generally, you need to find an area with good exposure to winds, like hilltops, shorelines, or open fields. The impact of neighbouring trees and houses can be significant, as it causes turbulence. Many wrongly assume that all you need to do is get above the trees to find the good winds. But the impact of trees and structures on wind goes far above the treetops. Tall towers matter. In the big wind game, it is assumed that there is turbulence as high as twice the level of the trees. Turbulence in wind is hard on equipment, and is far less productive than a smooth laminar flow.

In addition to the satisfaction of greater independence from the utility, you get the satisfaction of knowing that the electricity from your system does not contribute to smog, climate change, acid rain, resource depletion, or long term toxic waste storage. The cost per kWh from small wind generally costs more than from large wind, but because it is generated where it is used, it is also worth more. Ontario has a net metering program, that lets you run your meter backwards when you are producing surplus power. Or you can design your system so that you never generate surplus power, but rather just use a dump load when you have surplus energy. This can avoid some of the utility connection hassles.

The simplest way to avoid the contribution to smog is just to buy green energy. Bullfrog Power, Select Power, and Greentags are easy ways to do this. But buying green power is not as much fun as making it yourself.
Small wind can be either grid tied, or stand alone with a battery system. For areas far from the grid, where the cost of grid connection is high, wind energy can cost less than grid connection. There are small wind turbines in use in West Virginia to power road signs. And wind turbines are a common site on sail boats, which are especially difficult to grid tie! Islands, camps and cottages are other good applications that are cost effective.
The economics of grid tied systems are more challenging. For some, wind and solar becomes a hobby – people spend a lot of money on hobbies without a return on investment, so spending on a hobby with a return, however small, can be very satisfying. And small wind turbines are a great conversation starter.

Stand alone battery based systems are fairly simple. Generally, a dump load needs to be available when batteries are full. This can be as simple as a heater, which comes on when surplus power is available. A typical system includes a wind turbine, inverter to convert from 12 V to 110 V, and batteries. Often, small wind is combined with solar to create a hybrid system. Wind and solar are very complimentary, as winter has the strongest winds, and summer has the most sun.
While small wind and large wind differ substantially in technology (large wind turbines blades pitch to shed wind in high winds, they use active management to face upwind, they are on far taller towers etc.), they both suffer greatly from policy challenges. Zoning rules for small wind are inconsistent, and range from indifferent, with no problems, to prohibitive. Metering rules by Weights and Measures Canada prevent the use of most standard meters as they are not certified to run backwards. This can raise the cost of meters. Utilities have varying interconnection rules, and often add cost through the addition of external disconnects, added cost for inspections, and metering regulations.

We are so paranoid about accurate metering and safety, that we use a sledge hammer to kill a mosquito. If a small wind turbine generates 2000 KWh/year, and the meter runs backwards 10% of the time, then we are measuring 200 kWh to feed onto the grid. If the meter running backward is inaccurate in the backward mode by 1% (likely a higher error rate than may exist), then we are talking about a measurment error of 2 kWh. That’s worth 20 cents. How much extra should we pay for metering to reduce this error? About $2. But of course the added cost far exceed this. The same is true of safety. The utilities are afraid that a wind turbine will continue to generate when the grid is off for maintenance. But inverters and turbines generally have controls to prevent this. Are visible external disconnects really necessary?

Paul Gipe has written a good book on small wind systems, called Wind Power: Renewable Energy for Home, Farm and Business. It would be a good start in learning what systems are available. If you are more the hands on type, Dave Cooke at True North Power offers weekend courses that provide good information. When the courses are in Lion’s Head, he often includes a tour of the Ferndale Wind turbine.  The American Wind Association has a good site on small wind, as does CanWEA.
The cost of small wind is decreasing as the volumes increase. Inverters in particular have had significant cost decreases in recent years.

So why not consider making your own electricity?

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