Small-scale Hydro Allows AK Family to Live Off-Grid
photo of Juneau at night by Jeff Huffmann
When I think about people who live off the grid the first thing that pops to mind isn’t hydropower. Solar panels, small wind turbines, geothermal? Yes. Technology that dates back to 1870? No. Granted, the number of sites where small-scale hydro can work for a home are more limited than those which are suitable for other technologies. Perhaps that’s part of it. In any case, as an example of what can be done if the site suits witness the Shaul family of Juneau, Alaska. The Alaska Journal of Commerce has the detailed story, but here’s the summary.While other Juneau residents were forced to deal with 400% electric price increases last month after an avalanche knocked out the city’s connection to its main power supply, a large hydroelectric dam, the Shaul family kept the lights (and refrigerator, and everything else in their 1,500 square foot home) on in the same way they had been doing for the past ten years: a Pelton wheel.
Victorian-era hydropower technology at work in 21st centuryA what? No, not being an expert in small-scale hydro installation (or history), I hadn’t heard of one either. Basically a Pelton wheel is a form of water turbine which dates back to the 1870s yet remains one of the most efficient designs.
The Shauls have theirs hooked up to a gravity-fed system which pressurizes the water, turning the wheel, which is attached to a bus alternator to generate the electricity. The system generates 7.5kWh a day, which is more than adequate for their meagre requirement of 3 kWh. Such low daily electric demand is achieved by using only the most efficient appliances, combined with heating the house and doing some cooking using a wood stove.
Looking Backwards to Progress?Those interested can get more of the details in the original article (linked above), but for me the point to take away is that we should not only being looking forward via high tech solutions to our environmental and energy problems, but also looking backwards. We have hundreds of years low energy intensity knowledge to draw upon. Obviously not everything will be appropriate, and not at all scales of deployment, but some of it may be.