How small-scale hydro power could transform on-farm energy woes

Dorrigo-based engineer Peter Lynch has 21 years experience building and servicing micro-hydro solutions for communities in the Pacific Islands and says the same technology can be applied to Aussie farms, without the need to build dams or block river flow.

A one kilowatt hydro can cost about the same as a four kilowatt solar system, except that hydro runs 24/7 and streamflow can be forecast months ahead - unlike the daily ups and downs of sun and wind.

"If you draw a line down the Great Dividing Range of NSW, 42 per cent of the total volume of water that falls as rain falls to the east and yet 92 per cent of hydro power energy production involves water that flows to the west," he says. "Clearly the majority of action is hydro possibilities are on the eastern side.

“There has been an assumption for decades that hydro-power is mature and exploited because we are on a dry continent but there are enormous opportunities at smaller scale.”

For dairy producers who cool down milk and wash out the bales early in the morning and after dark, when there is no solar generation, hydro can offer another way to lower crippling bills.

For irrigators dependent on pumping, small scale hydro can be used to lift stream water to elevated off-stream storage from which water can run with gravity.

Making power from a flowing stream is one of the oldest forms of renewable energy but the modern pelton wheel combined with electric generation has improved the end use substantially.

Mr Lynch advocates a “run of river” approach that needs no dam, simply borrowing water from the running stream for a short distance through a pipe which in domestic situations is no more than 50mm in diameter.

"Run of River" says Mr Lynch "is environmentally benign and allows for up and downstream fish passage as no dams are needed."

The turbine itself can be small enough to fit in a wheelbarrow with something like a dog kennel to protect it from the elements.

Mr Lynch says farmers are always keen to know what works and what doesn't, what they can fix with their own tools and what they can't. When it comes to small scale hydro those questions can be answered. Proof comes in the number of sustainable power plants operating for more than 20 years in the Pacific Islands with minimal maintenance yet high reliability in most cases.

Of course there are bigger schemes that can power entire communities, and this is what Mr Lynch does - mostly providing power plants for villages in Papua New Guinea, Solomon Islands and Vanuatu where governments are pleased with Mr Lynch's Australian company's construction and back up service.

One community in the Solomons was subject to an illegal logging attack in 2004, with timber harvested in a military-like operation and loaded onto barges which sailed into international waters before the sting could be reported. Erosion followed silting up the village harbour so fish could not longer be caught locally. But when islanders paddled their canoes to outlying reefs they were disappointed find bait fish being netted by passing illegal tuna vessels.

The installation of an eight kilowatt hydro power plant brought new security, with the ability to value-add agricultural produce and earn an income.

The next time an illegal logging attack took place a village resident who had bought a mobile phone with his disposable income reported the theft to police. The village paid for a lawyer and got an injunction. In the final wash-up the logging company had to pay for harbour clean-up and provide round logs to residents for their own use as compensation.

Suddenly, with a little bit of renewable power, the village had become empowered.