Island Power x2

Off-Grid and On-Grid
Intermediate

Inside this Article

Hydro Intake
Just below the spring, the hydro intake collects 50 to 1,200 gallons per minute, depending on the season.
High-Density Polyethylene (HDPE) Pipe
Both systems utilize butt-welded, high-density polyethylene (HDPE) pipe.
Map of Turbine Locations
Two hydro turbines utilize over 750 vertical feet of head from a mountainside spring near East Sound on Orcas Island, in Washington State.
Harris Hydro 5-inch Pelton Turbine
The Harris Hydro 5-inch Pelton turbine is driven by four nozzles at about 50 psi, spinning a permanent-magnet generator that produces up to 1 kW during the wet season.
Polyethylene Welding Machine
A polyethylene welding machine was used to assemble the upper penstock.
OutBack Power Systems Inverters
OutBack Power Systems inverters convert DC hydro power to AC for the author’s home.
Blasting the trench for the penstock
Water pressure was used to blast the trench for the lower penstock.
Eric Youngren Connects a Flange Adaptor
The author connects the 6-inch steel pipe to the HDPE pipe with a flange adaptor.
Steel Pipe Used in the Lower Penstock
One thousand lineal feet of steel pipe was used in the bottom of the lower penstock. The steep terrain necessitated creative installation and anchoring systems.
Canyon Industries Turbine
The Canyon Industries turbine consists of a 10.5-inch Pelton turbine and a 60 kW, 480 VAC, three-phase alternator.
Eric Youngren with a 10.5-inch Pelton runner
The author with the 10.5-inch Pelton runner for the Canyon Industries turbine.
Thompson & Howe Grid-Protection Panel
The main component of system integration is a Thompson & Howe grid-protection panel that disconnects the turbine from the grid during power outages and maximizes power output by regulating flow rates, maintaining consistent head pressure.
Hydro Intake
High-Density Polyethylene (HDPE) Pipe
Map of Turbine Locations
Harris Hydro 5-inch Pelton Turbine
Polyethylene Welding Machine
OutBack Power Systems Inverters
Blasting the trench for the penstock
Eric Youngren Connects a Flange Adaptor
Steel Pipe Used in the Lower Penstock
Canyon Industries Turbine
Eric Youngren with a 10.5-inch Pelton runner
Thompson & Howe Grid-Protection Panel

During the winter of 2003, I built my first microhydro system on Orcas Island in Washington state’s San Juan islands. At the time, I was installing RE systems all around the Islands. I found a spot on my family’s land where I planned to build an off-grid, microhydro-powered homestead. The system was designed and the cash saved for the materials.

As luck would have it, one day I got a call from Home Power’s Ian Woofenden, who lives on nearby Guemes Island, inquiring about any microhydro projects that could serve as a hands-on workshop.

I jumped at the chance to have a 20-person crew for a day. Installation of the 4-inch-diameter HDPE pipe would be a big job and a good time to have a bunch of people to help. The workshop also provided a serious deadline, an extra impetus to get the rest of the system elements in place. Our goal was to be ready with everything so that the workshop participants could install the pipe, connect the turbine, wire the controller and batteries, and then open the valves to make power—all on the same day.

Microhydro History

In 1978, my family moved to Orcas Island from the suburbs of Seattle. As a kid, I spent many happy days playing in the creek that flows through my family’s land, from the spring 1,000 feet up the side of the mountain to where the water joins the ocean in East Sound. Like most kids, I learned about the power of flowing water by playing with it. We built pools and dams in the creek, digging new channels for the water to follow as it was pulled ever downward by gravity’s incredible power. In the early ‘80s, my dad and some of his friends started raising salmon in the ponds and creek channels of the lower sections of the creek (see “Long Live The Kings” sidebar).

Starting with the first homesteaders in 1875, everyone who has lived on this land has captured and utilized the bounty of water flowing down the mountain for drinking and irrigation. In earlier days, they also made electricity with the water, but the last hydro-electric system (before I started installing them) appears to have stopped working in the 1950s or early 60s, around the time when the local rural electric co-op installed submarine high-voltage cables to bring Columbia River-generated grid power to the islands.

As a teenager, I learned about the basics of hydro power and started reading Home Power magazine, scheming and planning for the day when I could build a system of my own. I learned about the power potential of head and flow, and the dangers of water hammer through trial-and-error experiments and the occasional, spectacularly wet, destructive blowout. I came to truly understand how voltage and amperage combine to create electrical power when it was explained how these two variables behave in the same way that head and flow combine to create hydro power.

System 1: DC Off-Grid

Planning the Penstock

For my home site on the family property, I chose a spot up the hill to be close to the spring—a 1-acre flat shelf about 900 feet up that projects out from the steeper slopes of the mountain above and below it. The spring sits about 80 vertical feet above the house, and about 700 feet to the northeast.

I found evidence of previous plans for hydro power: A small intake pond had been excavated in the creek at a spot with rough road access. A simple plywood dam and plastic-lined pond backed up the water to channel it through a rectangular weir for measuring creek flow. That was the easiest and most logical place to build the intake for my system. Because it sat about 50 vertical feet above the house site, I would also be able to use the hydro intake to supply pressurized domestic water to the house. A narrow, level bench at the bottom of a 100-foot drop, about 50 feet lower than the house site and 650 feet to the north, was the best place to site the turbine.

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Comments (1)

Tim Loree's picture

Thanks Eric, for a very good article.

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