CALGARY – A 47-metre-high wind turbine that could soon tower over a school ground in a residential area of south Calgary makes no economic sense, according to a prominent renewable energy expert.
The city’s public school board says the $290,000 machine planned for Dr. E.P. Scarlett High School would pay for itself in 20 years.
But calculations done by the Herald using current market rates for electricity show it would take over three decades – longer than the turbine’s predicted lifespan – for the savings to equal the purchase price. The calculation makes no allowance for the cost of maintaining or decommissioning the 50 kW generator and tower.
“From a purely economics point of view, it’s hard to make small wind work, particularly in an urban setting,” said Tim Weis, director of renewable energy policy at the Pembina Institute
“You get houses and buildings that slow the wind down and chop it up so it’s definitely not a good environment.”
While the giant turbines in Alberta’s Foothills that feed into the province’s power grid receive average winds of up to nine metres per second, wind atlas data show that the expected winds that would hit the blades of the Calgary Board of Education turbine would only average about 4.5 metres per second.
“Twice the wind speed means eight times the power, so you tend to see wind farms in areas that are far from any obstacles.
“If they’re going to do this, it needs to be for the education it will give with students or for the carbon offset it will produce.”
CBE officials have said the project will be an opportunity for the school’s environment club to learn about renewable energy, and that the power produced will be the equivalent of removing 14 cars from the road.
Frank Coppinger, the board’s superintendent of facilities and environment services, said the turbine is part of a $15.5-million energy performance contract the CBE has signed with Johnson Controls Inc. that also includes more efficient lighting and heating systems at 35 aging schools.
The contract is to be financed through a bank loan that will be paid back through energy cost savings over the course of the 20-year deal.
“The turbine is wound into the total package and Johnson Controls is guaranteeing the savings over a period of time,” Coppinger said. “Even if the wind turbine didn’t really work, I think we’d still be OK.”
While the CBE hopes to install the turbine next summer, the board will need approvals from both the city and the Alberta Utilities Commission before it can proceed.
Kim Hartley, a development bylaw co-ordinator, said the turbine could be permitted as “discretionary land use” after review and consultation with the community.
AUC spokesman Geoff Scotton said the board would need to consider objections from any area residents that might be “directly or adversely affected” and complete a noise impact assessment to ensure that nearby properties weren’t exposed to noise levels over 40 decibels.
By the CBE’s calculation, the nearest homes are 131 metres to the north, across Anderson Road in the Southwood subdivision. According to specifications from the turbine manufacturer, the turbine – when mounted on a 30-metre tower that’s shorter than the one proposed – produces 40 decibels at a distance of 110 metres from its base, but cannot be heard at distances that are more than 144 metres away.
Coppinger said if he lived near the proposed turbine, the only objection he might have would be the obstruction to his view.
“Putting this in a residential area is a first for Calgary, but as a local resident I wouldn’t have a problem with it,” he said.