A New Era in Home-Owner Hydro

Enlarge Image Image Gallery

Energy and Environment

Living off the Grid, Part III

If you thought hydroelectric power was only practical at the bottom of a cascading torrent of water... you're in for a surprise. Tapping the natural force of even small streams using modern turbines can offer a lifetime's escape from utility bills.

By James R. Udall

Two years ago, Norm and Sue Benzinger, owners of th Coulter Lake Guest Ranch, a wilderness retreat in th Rockies, had a problem: They were seeing too much of the propane delivery man.

The ranch's propane bill had topped $10,000 in 1992—much of it consumed by a generator. Hoping to slash his energy costs, Norm contacted Ken Olson, a renewable energy expert who directs Solar Energy International in nearby Carbondale, Colorado.

"He said he had a stream falling down the hillside," recalls Olson. "Turned out it was a great water power site."

Working together, Olson and Benzinger installed a hydroelectric turbine. Now the generator, which used to drone for hours a day, has fallen silent. A water power system that cost $6,000 will save $2,500 in its first winter.

Over the last 10 years, small-scale hydropower technology has taken a quantum leap thanks to the invention of the microturbine. Inside a metal case that is smaller than a bread box, a miniature water wheel, not much bigger than a cinnamon roll, is coupled to a pickup truck generator. When the wheel is spun by a jet of pressurized water, electricity is created. The design is simple yet sophisticated, a triumph of appropriate technology.

Progress has also been fueled by the dramatic evolution of solid-state inverters and load controllers—the brains in the Benzingers' system. A decade ago, inverters, which transform direct current (DC) to alternating current (AC), and con trollers, which govern electrical production, were dumb, unreliable, and inefficient beasts. Tamed with computer chips, they now perform the same tasks in a much more intelligent, reliable, and energy-efficient manner.

Together, these advances have revolutionized the world of homeowner hydro. Because a microturbine requires only a few quarts or gallons of water per second, it's now possible for even a slender stream to provide all the electricity a house or modest farm requires.

Although this technology sometimes makes sense for people whose homes are already connected to the utility, it's most economical for those living, or contemplating, life "off the grid"—a group that includes homesteaders as well as farmers and ranchers who irrigate or own water impoundments. With utilities charging $10,000 or more to extend power lines a mile, an understanding of hydro basics can prove valuable indeed.