As the new year dawned, so did a new chapter in Alberta’s renewable energy industry. After many years of planning and construction, the Halkrik wind farm is now actively producing power for customers across western Canada.
Indeed, the facility’s 83 turbines present a striking image on the prairie landscape, but few appreciate what actually goes into harnessing the power of the wind and converting it into electricity.
It’s a fascinating step backwards for energy generation on the prairies — the return of wind power. In the 1900s farmers used windmills to pump water for their homes and their fields. Today, wind power is once again relied upon to provide a much needed resource to those who work the land.
At the helm of this vast plant is Capital Power’s Ryan Bell, a tall, youngish presence whose easygoing demeanor seems more at home on the slopes of Whistler than managing Alberta’s largest wind farm. His easy going attitude belays the seriousness of his job: ensuring the windmills keep turning safely and productively.
Originally from New Brunswick, Bell was one of the first graduates of the Wind Turbine Technician program at Lethbridge College in 2004. Starting his career in Pincher Creek, Bell’s path to Halkirk took him to wind energy projects around the world — bringing a truly global experience to his work.
Electricity’s road from the prairie to your home literally starts and ends in the sky. Eighty-three towering windmills use sophisticated technology to determine the best way to capture the wind. Despite their rather simple appearance, modern wind turbines are deceptively complex. Inside the glossy white exterior is a maze of complex machinery and electronics that constantly adjust the turbine’s attributes to best produce electricity. There is so much going on inside of a modern turbine that they each consume several megawatts of electricity just to keep operating.
All of this technology is essential to ensure wind is harnessed responsibly and efficiently. The simplest way to harness electricity from the sky, according to Bell, is to build a static wind turbine facing into the area’s prevailing winds.
“To actually produce clean power is a different story,” Bell said. “You can certainly capture power and just let it run, but your lights will be constantly going on and off with the fluctuations.”
“Or,” he added, “you can harness this energy into a steady stream.”
A system of decidedly low-tech sensors consisting of wind vanes and anemometers constantly feed data into the wind mill’s computers. The large pod at the top the windmill’s tower, known in the industry as a ‘nacelle’, is capable of rotating the turbine’s enormous blades into the wind, and fine tuning this rotation, to ensure constant and efficient power generation. The blades themselves are able change their angle, or pitch, to further refine the turbine’s efficiency. By adjusting blade pitch, the turbine’s 90 foot blades are able to take a bigger bite out of the passing wind to adjust their rate of rotation to keep the turbine from spinning too slow…. or too fast.
When wind speeds reach 23 meters per second (90 kph), automated safety systems will shut the turbine down and bring the blades to a safe stop. Turbines pushed past their limits can be severely damaged, which is why the units are constantly measuring windspeed.
A transmission inside the nacelle converts the turbine’s leisurely 12 rotations per minute into a speedy 1200. An electrical generator connected to the gearbox produces electricity from this rotation. An on-board transformer bumps up the voltage from the generator to 35,000 volts, which is then transmitted down cables in the mast to an underground distribution network, eventually reaching a substation located between Halkirk and Castor. The substation will ‘clean’ up the electricity and send it out to Alberta’s power grid via a series of aerial high tension cables.
The plant itself contributes 150 megawatts to the provincial power system, enough to power 50,000 homes. The price for this electricity on the open market is free-floating — that means that the price per megawatt is determined by province-wide demand for power at that moment.
“Our power could sell for $8 per megawatt, or it could sell for $699”, said Bell. “It’s almost like putting your money on the stock market.”
According to Bell, it costs $2 million to construct each turbine, a price that includes purchasing, shipping from Europe and installation. Merely paying for and building the plant isn’t the end of the road, though — a large part of Bell’s job is maintaining a positive relationship with local landowners, whose land was used to construct and maintain the facility.
Bell describes his reception by the landowners as “excellent.”
“They were very supportive,” he said.
In September, Capital Power hosted a blade signing event to allow local residents a chance to make themselves a tangible part of the facility. The signed blade is currently installed on Turbine 52 located off of Range Road 155 south of Township Road 382, southeast of Halkirk.
The future of wind energy in Alberta, according to Bell, is very much vested in technology. This is why wind farms are starting to appear in less windy areas of Alberta such as Halkirk.
“With the older turbines you needed 11 meters per second winds to get maximum capacity — now it’s four.” he said. “Here on the ground, the wind might only reach two meters a second, but 30 meters up, it might be closer to 20.”
As technology, attitudes and the need to find workable sources of renewable energy, ambitious projects right in our own backyard will help shape future projects for years to come.