Water Rites

A Microhydro Evolution
Intermediate

Inside this Article

The author with the new turbine.
The author with the new turbine.
The view downstream along the weir.
The view downstream along the weir.
Microhydro turbine manufacturer Paul Cunningham measures the penstock.
Microhydro turbine manufacturer Paul Cunningham measures the penstock.
The author works on attaching the penstock to the stand box.
The author works on attaching the penstock to the stand box.
Up and running—the first power output test.
Up and running—the first power output test.
The new and improved clean-out procedure.
The new and improved clean-out procedure.
The old, cold clean-out procedure.
The old, cold clean-out procedure.
A close-up of the custom leaf mulcher.
A close-up of the custom leaf mulcher.
The power wall.
The power wall.
Here, the stand box is coated with silt from a flood
Here, the stand box is coated with silt from a flood, but the turbine itself is easily removed if the river is approaching flood stage.
The author with the new turbine.
The view downstream along the weir.
Microhydro turbine manufacturer Paul Cunningham measures the penstock.
The author works on attaching the penstock to the stand box.
Up and running—the first power output test.
The new and improved clean-out procedure.
The old, cold clean-out procedure.
A close-up of the custom leaf mulcher.
The power wall.
Here, the stand box is coated with silt from a flood

Every morning, before brushing teeth or having a look at the weather outside our Victoria, Australia, off-grid home, my wife Carrie or I pad downstairs to the battery room to check the meters that monitor our electrical system. The reading determines whether we use the propane stove or the electric jug to heat water for our tea. Since our microhydro plant upgrade, it’s usually the jug.

This ritual has become a part of our daily lives, like making the bed: A quick look at battery voltage and power from our microhydro system. It used to be a stomach-churning moment for us: Our previous microhydro turbine was dysfunctional too often due to its poor design, which meant a trip down to the river to clean the turbine blades—an uncomfortable and sometimes life-endangering task. Since replacing that “experiment” with an Energy Systems & Design (ES&D) LH1000 low-head turbine, complete with a prototype “leaf-mulcher,” and new PV modules to back up the hydro, off-grid life’s simply blissful.

Off-Grid with Comfort

Living in the most remote part of the Victorian Alps, 15 kilometers (9.3 mi.) from the electric grid, has not reduced my appreciation for flipping a switch rather than filling and lighting kerosene lanterns, using circular saws instead of hand saws, or for using other time-savers like toasters and microwave ovens. 

These days, although I’m an active 53 years old, I’m not content to spend my time chopping wood for cooking. Nor do I care to write by lantern light, or pull a coolish beer out of the river. Instead, I want plenty of free time to go trekking, kayaking, and skiing. Plus, I like my beer ice cold!

For the first few years, we had big problems with our original, locally engineered hydro plant (see “Choosing Microhydro…” in HP101). We feared that we’d made a huge mistake, as our time, money, and energy was sucked into the hydro like leaves. Friends and neighbors shook their heads at our folly. But our recent turbine upgrade has markedly reduced our “power plant management” needs, freeing several daily hours for ourselves, and now our off-grid life is good.

Microhydro Madness

It wasn’t until after we installed our first contraption that we discovered it was a manufacturer’s experiment in low-head axial turbines. Its many 90-degree angles impeded flow, making it inefficient. Its access port to the blades was too small for an average-sized adult, and usually under water, making debris clearing a freezing-cold, often dangerous nightmare. We kept a cardboard “turbine box” near the back door stocked with a dry suit, goggles, snorkel, life jacket, and safety rope. No kidding.

The turbine’s poorly designed blades often came loose and rotated to the wrong angle, either jamming the unit or causing the turbine to lose a lot of power. The complete turbine weighed in excess of 200 kilograms (441 lbs.), making its removal a time-consuming process that required a winch.

Another unfortunate problem was that we weren’t informed to build the intake with debris screening in mind. All hydro plants have to contend with leaves, sticks, and other detritus. Because of the turbine and intake’s design, we had to fiddle and mess with the turbine often, sometimes as much as three times a day. In contrast, a well-designed turbine intake should require a screen- or blade-cleaning perhaps once a week or, during summer low flows, once every few weeks. Unfortunately, when we first built the weir, we did not understand the importance of a debris-screening strategy. Proper design greatly minimizes, or can even eliminate, manual debris removal. Including screening in the original design would have been easy, but now such an addition would be more difficult.

Our original turbine’s 350-watt maximum output usually lasted only an hour or so after debris was cleared. After that, frequent checks of our Plasmatronics PL20 display would show the power declining steadily until we’d take our next forced march down the steep hill to reclean the turbine blades and intake screens. I dreaded the next flood or power drop, and dreamed of just going back to loving whatever mood the river was in. That cranky turbine cost us AU$6,000—three times more than the new ES&D LH1000 we replaced it with. Our naïveté and rush to build the hydro system cost us dearly—in money, time, and energy. On the plus side, we learned heaps about microhydro systems and renewable energy, and had in place all the other balance of system equipment—wiring, batteries, inverter, and regulator—for a new turbine. But we’d finally had enough—after five years of struggle, our patience and nerves were at an end, so we decided to replace the flawed turbine.

Through a microhydro e-mail list-server group (see Access), we received advice from several folks. Paul Cunningham, of ES&D in Canada, read my Home Power article from 2004, and felt that one of his turbines would work for us. The LH1000 turbine he recommended was a fraction of the size of our original turbine, weighing about 20 kilograms (44 lbs.). It has a strong, cast bronze runner/propeller, and could be made to offer blissfully easy access for unclogging.

We decided to give it a try and ordered one. Though Paul offered excellent support and advice over the phone and Internet, we invited him to visit us in Australia and help with the installation, and he accepted.

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