If researchers have their way, farmers may some day be able to irrigate using only water and the power of the sun.
The Canada-Saskatchewan Irrigation Diversification Centre at Outlook, Sask., is conducting trials to determine the feasibility of using only solar power to operate and supply water to a centre pivot irrigation system.
“It is very new in the world, so we are trying it out,” said Jazeem Wahab, acting manager of the centre, adding that this project is a first for Canada.
“The concept is not new, but the application is new.”
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This Agriculture Canada solar powered mini-pivot irrigation system may prove ideal for remote land that does not have access to power.
In the past two years, short crops including vegetables and cereals have been grown successfully using this system, though Wahab said they have been looking primarily at higher-value crops due to cost efficiency.
The environmentally friendly system has two solar panels which measure 0.56 sq. metres each. The panels power eight six-volt solar batteries, providing enough energy to water four acres of land.
Wahab said his researchers want to refine the uniformity of water application so that they will make the best use of the water supply and the irrigation equipment.
“We are looking at how to adapt it to different situations because we still don’t know a lot about the engineering and the mechanisms and the water distribution.”
Terry Fonstad, assistant professor in the department of agricultural and bioresource engineering at the University of Saskatchewan, has been working on the project and said the solar panels power the pivot wheels to make the irrigation system go around the field, but a more economical diesel engine pumps water from the source to the pivot.
Ultimately, he wants to harness solar energy to power both the pivot and the water pump.
“Presumably, if you can get water on for strictly the cost of the pivot, the power to pump the water and turn the thing around is basically free,” he said. “If we can do it now with the solar panels we have today, the solar panels and batteries will only get more efficient in the future.”
Both Wahab and Fonstad said the solar-powered mini-pivot irrigation system could work on any crop, though it likely wouldn’t be economical to irrigate a large parcel of land.
In a conventional irrigating system, one might apply an inch of water to a large field in 24 hours, then leave it for a week, said Fonstad.
Solar power cannot deliver this kind of short, intense spray, but rather a slow, gentle application.
“…It’s almost a drip irrigation system that runs around in a circle,” he said.
“You can’t pump 1,200 gallons a minute with a solar panel. What we’re talking about is running low pressure, so you’re less than 10 psi at 20 gallons a minute.”
Fonstad has been supervising U of S grad student Evan Derdall, who’s been working on the project since May. Derdall’s goal is to monitor the system and devise a plan to use the batteries most efficiently while keeping soil moisture at optimum levels.
“At the end of the day, he should be able to give us a best management practice for running a miniature pivot system, based on a sustainable energy consumption, strictly on solar,” said Fonstad.
