Demystifying the Science | Hydroelectricity at the Cottage

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Yes, but there are administrative procedures to follow.

“Quebec is one of the strictest jurisdictions in Canada for installing a turbine in a waterway,” says Pierre Blanchet of Montreal-based renewable solutions provider Idénergie. “You have to apply for a lot of permits.”

An installation that requires a small dam is even more complicated to legalize. “I sold a turbine to an outfitter 100 km from any village, for an installation at the outlet of a lake,” says Roch St-Pierre of Micro-Énergies, a renewable energy consultant in Hemmingford. “Since there is a dam, it requires a lot of steps.”

A turbine can be installed along the water in a river. This is called a hydro turbine. Part of a watercourse can also be diverted into a “force conduit” to take advantage of a difference in level.

The run-of-river turbine is the most affordable solution. ORPC Canada, a provider of renewable energy technologies for isolated communities, has just teamed up with Mr. Blanchet to develop a residential turbine that can be installed in just half a metre of water. The tidal turbines typically installed by ORPC require at least 3 to 5 metres.

“A simple way to know if the speed is sufficient is to throw an orange or a biodegradable object into the water and observe its speed over about 10 m,” explains Fabienne Joly, Director of Development at ORPC. “If the object takes less than 7 or 8 seconds to travel the distance, then the portable hydro turbine could generate energy.”

The residential turbine, which will be launched this fall, would generate at least 2.4 kWh per day, enough for two refrigerators, lighting and computers. The cost will be between $6,000 and $10,000, with the electrical system including batteries.

However, it will generally be necessary to remove the hydro turbine before the January ice, to avoid damaging it, according to Mr. Blanchet.

Difference in height

If you want to take advantage of a difference in level in a watercourse, for example a stream that swells during rains, you generally need a penstock to bring the water to a turbine, according to Mr. Blanchet. “However, you need water heights of 2 meters or more and fairly significant flow rates in cubic meters per second, which are not a given in nature.” He uses calculators from the French site turbiwatts.

Mr. St-Pierre warns that you shouldn’t improvise as a hydroelectric equipment installer, and not only because of the risks of dams. “If you have a poorly sized penstock, it can crack and there is a risk of metal being thrown out.”

Customers have also contacted Mr. St-Pierre to install a turbine in their home linked to the aqueduct. “It’s really a waste of energy, because it’s pumped water, and it’s drinking water.”

Calculate the potential of a stream with a drop

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