Vertical Wind Generators - Sometimes a Better Choice than Horizontal

With the rising price of fuel oil, and the rising costs of energy in general, there is increasing demand for home generated power, be it from solar-electric, solar thermal heating, or wind generated power. Of those three options, wind generated power is by far and away the most mature option, with the best odds for getting a reasonable payback in a typical home owning time frame.

With wind power generators, there are two general types to consider: Horizontal blade generators, and vertical wind generators. Horizontal generators are the type most people associate with a windmill or wind generator - they have blades that rotate perpendicular to the ground, with the axis of rotation being horizontal. They have significant advantages in efficiency, but work best when put on a tower, where they can catch the upper contrail winds, and they're more mechanically complex. On top of this, they're also a hazard to birds, and can be quite noisy.

For rural applications, horizontal generators reign supreme. When attached to someone's home for net metered power generation, they run afoul of local zoning ordinances and home owners associations, because, bluntly, there's no real way to make a 35 tall wind turbine look like it's part of a Victorian deco home plot. Couple this with dead birds, loud noises, and people afraid they'll blow over in a storm, and there's a lot of barriers to installation.

The best choice for a homeowner is a vertical wind generator, which rotates on a vertical axis. There are drawbacks - they're about half as efficient as the more traditional wind turbine, and they may need a small "boost" from an electric motor to get their initial rotation going; their minimum threshold for usable wind is a bit lower.

On the other hand, vertical wind generators have the advantage of being suitable for a ground level installation. They can be put out in the middle of the back yard, or on top of the roof of your garage. They're much quieter in general than horizontal generators, and because they operate at a lower altitude, they're less likely to kill birds. They also don't need a yaw element (the "tail" of a conventional turbine blade) to steer them into the wind direction, as they can generate energy from any wind direction the breeze is blowing in from.

Another benefit of vertical wind generators is the range of vendors supplying them; horizontal generators are good for industrial applications, but they're often $12,000 or more to install. Vertical wind generators are often under $5,000. With most electrical prices set the way they are, a vertical wind generator can pay for itself in home use in around 20 to 25 years. (A horizontal generator will be more efficient, and generate power at a lower baseline wind speed, making its higher up front cost make more sense).

Vertical wind generators are also (generally) more aesthetic. They're less likely to be noticed as being an odd addition than a 36' tall tower would be. Some of the more aerodynamic ones tend to look like short rotating sculptures, and there are even bladeless or rotorless turbines.

The most common type of home deployed vertical wind generator is the Savonius type, which uses airfoils and wide variable pitch blades to generate power. Built more or less like large anemometers, they run into problems with generated drag; more efficient ones use variable formations on the blade to minimize drag when they're being swing through the incoming breeze.

The other type of wind generator is the so-called 'egg beater' windmill - they can scale up to the full industrial size installation, though they're also suitable for small home installations. They're much more efficient, but also noisier, and a bit more effort is required to maintain them.

Depending on where you're setting your vertical wind generator up, your local utility company may offer credits for doing so, and nearly 90% of the utility companies in the US offer some form of net metering, where excess electricity you produce from your vertical wind generator is sold back to them and credited against your bill. Look seriously into the options your utility company provides before investing in a vertical wind generator, and consider it an investment in cheaper power down the road.