MAIL: The Runaway Hydro

Beginner
Jeffe Aronson and his hydro turbine
Jeffe Aronson and his hydro turbine that takes a licking and keeps on ticking.

My article on our original microhydro system (“Choosing Microhydro” in HP101) included all the trials and tribulations we had with it. In 2007, we installed a LH1000 low-head hydro by Energy Systems & Design (see “Water Rites” in HP122). It sits in a rather flood-prone site, and is exposed to spring floods. After having moved tons of rock by hand, pouring an intake, hydro pad, and weir (dam) in that position (not to mention recently turning 60), I haven’t had the heart, money, or time to move it. To protect the site from the force of floodwater and the inevitable debris that comes along with it, the LH1000 is housed in a stainless steel box. 

Up until the southern spring of 2010, we just did what many hydro users do—fiddled with this and that to improve filtering, output, etc. While we love having the extra power to run tools, the vacuum, the washing machine, microwave, and most importantly, the cappuccino maker, without relying on combustion engines, hydros take a lot more “power plant control.” I set up the machine so that when we left for an extended period, it would take only a few minutes to detach and haul up the hill to our shed. However, if we were leaving for only a few days, we tended to leave it in, with all the flashboards buttoned up and the butterfly-valve intake shut.

We were gone for just a week visiting family, and had left the hydro at the river in the box. That’s when we came up with a doozy—a 100-year flood. It isn’t really about the water, which along the edge of the river, isn’t as powerful. It’s more about the logs and trees that have been sitting on the bank upstream for decades, and then come hurtling down.

We got a frantic phone call from our neighbor, but as we were 2,000 kilometers away, clearly it was too late, so I had to make do with a shot of single malt. When we returned, we found the box bent beyond use and the hydro gone. 

With our turbine missing, we decided to just add more PV modules to our existing array. At 1.8 kW, it provides us with just enough electricity—usually. If the weather is cloudy, or during the short days of winter, we may have to forego the vacuum, microwave, and perhaps most importantly, my cappuccinos. 

And then, a year later, a little miracle happened. A friend who was fishing just downstream of our place saw a glint in the gravel, and went to investigate (perhaps hoping for some gold in the local granite). After a bit of digging, he unearthed another sort of treasure: our turbine! We cleaned it up, epoxied the chipped plastic intake vane, replaced the bearings, and re-threaded the shaft housing into the vane base. We then re-installed it into a quick-and-dirty plywood box and placed it in the stream. The dang thing worked like a charm!

We replaced the stainless box with a newer, sturdier version with rebar and are installing an extra set of flashboards on top of the footbridge and weir to give the turbine an extra 12 inches of high-water protection. We’re also replacing the 2-by-4 log deflectors with rebar both on top and upstream of the box.

We now enjoy our cappuccinos once again—rain or shine—and we have more power than we know what to do with, no clanking smoking engines ruining the calls of the kookaburras, and the cleanest, most consistent power in the valley. I still sit by the river and ponder how I could possibly improve the filtering, but now that the hydro is our backup rather than our only power source, I smile and enjoy my musings next to our little river, high water or low.

Jeffe Aronson • Victoria, Australia

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