February 2007 ISSUE

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STUDENT COLUMN

Tricky Challenges Blow Through Wind Farms

BY MARK SKOVMOSE
University of Calgary Student Columnist (Engineering)

Bob Dylan famously sang that ‘the answer, my friend, is blowin’ in the wind.’ Energy producers have taken those lyrics to heart in a literal sense by building wind farms and planning many more of them. But what will it take to get this clean, renewable energy source humming along at full song?

WINDS OF CHANGE Scenes like this one are becoming more and more familiar in Alberta and throughout the world. An Alberta cap on new wind power, however, could be a signal to energy producers that investment in cheap, efficient storage is needed.

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With discussion of climate change increasing, clean and renewable energy sources are in the spotlight. Many large oil and gas corporations are reforming themselves as energy providers, expanding their focus beyond the current staples.

Electricity in Alberta is primarily produced from coal and gas, but several developments in renewable energy sources are emerging. Wind energy has long been toted as an energy source that is not only clean and renewable, but also plentiful and inexpensive.

When other factors are taken into account, however, the choice is less simple than it might appear.

The investment into the development of 3,000 megawatts of wind energy production is $5 billion, to add to the 300 MW of it currently on the system. This investment equates to nearly 33 per cent of today’s total electrical load.

However, a recent cap of 900 MW on wind energy production imposed by the Alberta Electric System Operator has stalled much of this production. While investors are frustrated with this approach, the AESO reasons it must guarantee quality of service — and wind generation has the inherent uncertainty of unpredictable wind.

Consider an electrical grid that is substantially supported by wind and the wind suddenly dies. The load must be supported elsewhere or the entire system would collapse.

The inverse is also a problem. What if the wind is creating too much electricity for the system, without removing production elsewhere?

This issue is the focus of my class’s fourth-year project. We recently met with John Kehler of AESO to discuss the cap and industry’s response.

The operator, he said, has conducted two phases of a case study into the maximum potential that wind power can provide. AESO believes its imposed cap is justified. “As wind power increases on the system, operational uncertainty also increases,” said Mr. Kehler.

Prediction of the wind will allow operators to provide a higher degree of certainty they can guarantee electricity, but it cannot make up for the mismatch in generation and load.

Electrical grid connections with other provinces and the U.S. — sometimes called “inter-ties” by the industry — help stabilize the system. These inter-ties must be managed, however, and they bring new issues to the problem. A hiccup or incorrectly implemented system could echo through to an inter-tied jurisdiction and cause massive blackouts.

Backup and storage of energy seems to be the key to unlock wind power in Alberta, but reaching this goal comes at a cost. Storage techniques, such as compressed air and hydro pumping, are suitable but expensive.

Alberta’s geography doesn’t lend itself to efficient hydro systems. Massive reservoirs of varied heights are needed. Compressed air is noisy and has low efficiency.

Another option is backup plants that idle when the wind blows and generate power when it doesn’t. But idling plants don’t bring in revenue.

This need brings up the potential for energy storage to find its way into the market. There is much development and research in this area, but the amount is still small compared to what’s expended on primary resource extraction.

A cheap, efficient energy storage solution will find a solid market and aid in moving our economy away from non-renewable energy sources. Consider the shift of economics toward including the environment, particularly since the Kyoto Accord, and you start to see how important this is.

Clean, renewable energy has the potential to be a more cost-effective electricity solution as our carbon emission tariffs increase. It is also a more sustainable option as we reduce our dependence on depleting resources.