Living off the grid, Part IV: Catching the Wind

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Our first consideration was the tower. Typically, turbine manufacturers design their mounting plates to conform to the tower top. For example, Bergey uses the Rohn guyed-lattice tower, whereas World Power uses a guyed-pole tower. What this means is that you are something of a captive audience, having to buy a turbine specifically made for certain towers. And they don't come cheap.

The giant steel frame must be a minimum of 50 feet tall to reach stable air and preferably taller to ensure unobstructed airflow. It's hoisted to an upright position and stabilized with numerous guy wires; the turbine is then lifted on top by a crane (only experienced folk dare use a gin pole). The rotor and tail are installed in place and final electrical connections are made. Now, all that's required is a 7.5-mph start-up wind.

Maintenance schedules vary according to turbine design. Some towers are designed to be lowered to the ground for turbine maintenance rather than making you climb to the top. Contrary to some manufacturers' contentions though, lowering a 50–100-foot tower for any reason is no small job. The guy wires must be released and there must be adequate ground clearance and equipment with which to lower it. Maintenance is best left to the qualified and brave who are equipped with safety gear.

Now, that's how it should be done. Then there's the way we did it. We bought a 75-year-old, 4-legged, angle-iron windmill tower with lots of western character and no guy wires. We constructed two pivoting legs to tilt the tower—each in 1,500 pounds of concrete. The other two legs locked into place (see photograph).

We ordered a World Power Whisper 1-kW turbine and modified the tower top with a 2-inch pipe according to specifications. We assembled, wired, and mounted the Whisper before we raised the tower. Neighbors came to lend a hand and we pushed it up with our tractor. We flipped it on with ceremonious gesture — and at last it was up and working! Well, Murphy (and his Law) apparently had taken residence at our place. The blades were out of balance and the generator was shimmying...a lot.

We ordered a new set of blades and installed them without lowering the tower. Now it spun smoothly and we had more electricity than we could use — until 3 months later, when we spotted the tail lying on the ground and noticed that the nose cone was cracked. We learned that World Power previously had problems with the tail and nose cone design. They offered to replace the turbine , but we felt the Whisper just wasn't up to the challenge. We lowered the tower, removed the turbine, and shipped it back. World Power refunded our money. Based upon this experience, we always recommend that anyone who is considering a wind turbine ask the manufacturer for references for people who have had that model turbine in service for a couple of years in a location with similar wind conditions.

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