Living off the grid, Part IV: Catching the Wind

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Taking our own advice, we located Ed Wulf, a nearby resident who had a Bergey. He said it would "withstand our brand of wind." After much conversation, we ordered Bergey's BWC 1500, a 1.5-kW wind-power generator. It has three blades for better balance and turns out of the wind at 120 mph. This time around, we had the tower top configured by a technician who maintains 600-kW commercial turbines atop 160-foot towers. He also assembled and installed the turbine.

We built an outbuilding beside the tower to house the energy system. John designed it and had an electrician wire it to meet California's building code. Power generated by the turbine is processed through a controller and stored in a 24-V DC, deep-cycle battery array. From the batteries, a sine wave inverter supplies our 3,100-square-foot home and a 1,200-square-foot garage with 110-V AC electricity.

When the batteries are fully charged, power can be manually diverted to start the well pump to top off the 5,000-gallon water storage tank. If the inverter fails, a manual breaker switch automatically shifts to the generator. The system also operates a water filtration system.

The batteries are isolated in a well-vented, fire-walled room within the power center. Lead acid batteries are the weakest link of any alternative energy system; technology has simply not advanced to produce an affordable, long-lasting battery.

Our system is more than adequate, but this does not mean that it has no limitations. We are careful to turn lights off and wash only full loads of laundry. I sometimes iron clothes at midnight because that's when the excess power is available. But we have developed a sixth sense about our output capabilities ties. We even enjoy 27-W fluorescent lights (equivalent to a 100-W incandescent bulb), low-voltage garden lights, and motion detectors.

The cost for our hybrid system is about $10,000. Yes, it's a lot of money, but we didn't spend it all at once. We began with a 5-kW generator, inverter, and batteries. When we could afford it, we upgraded to a 10-kW generator. Then we bought the windmill and gradually added PV panels.

Statistics indicate that the operating cost of a 1,500-W wind system is $1.93 per watt. But the payoff for nonpolluting electricity cannot be equated in dollars. Its value is realized in terms of self-sufficiency and quality of life.

From Breeze to Batteries

A turbine converts the wind into electrical power. It consists of propellerlike blades (the rotor) and a generator. The rotor is what captures the energy of the wind and converts it into motion to drive the generator. A properly designed rotor turns the generator fast enough to produce maximum power but not so fast that it presents a danger to the system.

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