RENEWABLE ENERGY : MICRO HYDRO POWER SYSTEMS
This story is brought to you in part by Biomass Recycle
By Ronan O'Doherty
Despite being arguably the oldest renewable energy system, micro hydro receives considerably less fanfare than its cousins, solar and wind, do.
For off-the-grid enthusiasts across the world, however, it has been steadily gaining recognition as a reliable power source for those living near a water source.
That is the catch however, a water source, like a stream or river, with the right combination of head (the vertical distance the water falls) and flow (the quantity of water falling) is necessary to make the project worthwhile.
"If you have a suitable water source, it's definitely the most cost effective power source compared to other renewables," says Paul Cunningham, the owner of Energy Systems and Design, " It's also the steadiest as it's doesn't go off every night and the most predictable as water may dry up in the summer but it doesn't dry up overnight, " adding, "If you have a suitable source, that would be the system of choice."
Cunningham started Energy Systems and Design over 35 years ago but his interest in micro hydro goes back much longer.
"My father taught mechanical engineering and I think the book I read first was the Boys Book of Engines, Motors and Turbines," he said, "When I was ten or so I built my first water wheel and put it in the backyard."
Needless to say, the micro hydro systems of today are slightly more sophisticated than what he was building when ten.
The waterwheel it turns out, it not quite as efficient as the turbine.
The majority of micro hydro systems for a small to medium sized house use an impulse turbine. The most common of which are the Pelton Wheel and the Turgo Impulse Wheel.
The Pelton Wheel uses jet force to create energy. Water from the stream or river is funnelled into a pressurized pipeline with a narrow nozzle at one end. The water sprays out of the nozzle and strikes the double-cupped buckets attached to the wheel. The impact on the curved buckets creates a force that rotates the wheel at high efficiency rates of 70–90%.
The Turgo Impulse Wheel is an upgraded version of the Pelton. It uses the same concept, but the Turgo jet, which is half the size of the Pelton, is angled so that the spray hits three buckets at once. As a result, the wheel moves twice as fast. It's also less bulky, needs few or no gears, and has a good reputation for trouble-free operations.
The energy these turbines create, like that of wind and solar, is stored in batteries to use at the owner's convenience.
According to Energy Systems and Design's website, the magic number for powering an off-grid house is 300 watts of continuous power.
This is enough power for lights, fridge, freezer, washing machine and well pump for a family of four.
"I must say that most of our systems are unpermitted outlaw systems because they're so small they're not disrupting anything," said Cunningham, "Any water they do take gets put back in the brook. It's not like irrigation, where it doesn't go back."
He believes his company could help out in a greater way than the off off-grid house, however.
"If I could interest the First Nations communities in this, that would be great," he said, "They don't have to deal with permitting and can just do it."
Beyond that, he's hoping a shift in viewpoints on renewable energy starts to happen sooner than later.
" It's like my late friend Richard Perez said, if renewables got the same subsidies as fossil fuels did we'd all be flying solar powered helicopters by now," adding, "We have two choices for the future - A planned transition or an unplanned transition - Which would you prefer?"