Karl is just one of the many entrepreneurs and inventors profiled in the Discovery special who are creating new ways to power our planet — tapping sunlight, wind and water, and heat embedded in the Earth. Based on the companion book, The New York Times bestseller Earth: The Sequel, the show details the tremendous strides being made across the nation to solve the energy crisis and curb carbon emissions through new technologies.  From start-ups harnessing hydro-power from New York’s East River to solar power in New Mexico’s high desert, the show chronicles dazzling ingenuity and possibility.

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Home Power magazine has collected information about a wide range of different wind turbines that are available for home or small business use. The 2007 Wind Turbine Buyer’s Guide is a small but information-packed article with a wealth of information about available turbines for small wind systems.

The review has information on 19 different small wind turbines ranging from 7 feet to 56 feet in diameter, including systems for battery charging, as well as batteryless grid-tie systems. The list concentrates on some of the more widely available turbines, though many other manufacturers are selling turbines these days. Models from Abundant Renewable Energy, Bergey Windpower, Eoltec Wind Turbines, Kestrel Wind Turbines, Proven Energy, Southwest Windpower, Vestas, and Wind Turbine Industries are included on the list.

"Small wind," in our definition, starts with turbines with rotors (turbine blades and hub) that are about 8 feet in diameter (50 square feet of swept area). These turbines may peak at about 1,000 watts (1 kilowatt; KW), and generate about 75 kilowatt-hours (KWH) per month with a 10 mph average wind speed. Turbines smaller than this may be appropriate for sailboats, cabins, or other applications that require only a small amount of electricity. But if you want a significant amount of energy, you need a rotor with significant swept area—it is, after all, the wind turbine’s "collector."

In addition to the comparisons, there is good information about what the various components of a wind turbine system are, explanations about how the rating information was gathered, and a short section on wind turbine basics, that briefly covers the internal workings of a wind turbine (like what a ‘yaw bearing’ does).

This guide certainly doesn’t substitute for more comprehensive guides about installing a wind turbine, but it provides the best comparative data on different models of wind turbines that I have found to date. The guide lists several comparative pieces of information about each model covered. A background graphic for each model shows the comparative size of its rotor area. In addition to providing the rotor diameter and the swept area, the guide lists the predicted energy output at average wind speeds for 8, 10, and 12 mph. This makes it very easy to do direct comparisons between two models.

Even more useful to many people who are wondering about whether or not to invest in a wind power system are the costs for these turbines (as well as an indication of what each system includes). These range from $1,995 for the 7-foot diameter Kestrel 800 (without controller or inverter) to $180,000 for the 56-foot diameter Vestas V-17 installed on a 132-foot tower. More than half the models included are under $10,000, and several of these are in the range of $3,000.

Application and warranty information for each model is also included. Some models designed for battery charging are suited for more different voltages than others are. A few models are suitable for either battery charging or batteryless grid-tied connection.

In addition to the information in this guide, you will need to collect a lot more information before going ahead and taking the plunge with a wind turbine for your own home or business. Knowing local regulations and requirements, as well as the wind profile for the property where you are considering putting a turbine, is also essential before spending thousands of dollars to put one up. But, since the turbine is the core element in a wind power system, an evaluation of the different models available is a good place to begin figuring out the right system for your own needs.

Links:
Wind Power Buyer’s Guide

Home Power Magazine