By Josh Garvey
LANSING, Mich. – Wind energy paired with coal could cause more pollution than coal itself, a study in Colorado and Texas said.
A coal plant is most efficient when it runs continuously at a certain level of production, says the study by Bentek Energy LLC, a consulting company hired by Colorado’s oil and gas industry.
Repeatedly raising and lowering coal energy production to back up wind energy, a process called cycling, causes a coal plant to release more pollutants, such as carbon dioxide and sulfur dioxide, than it does when at normal levels.
But critics say the study simply shows a minor problem that will be corrected as Michigan adapts to using more wind energy.
Wind isn’t enough on its own
“One problem with wind is that it’s intermittent as a resource,” said Jim Ault, president of the Michigan Electric and Gas Association. “You have to back it up with something for when the wind drops away.”
That intermittent nature can result in coal plants not operating at full capacity or full efficiency when paired with wind energy.
The study recommends against expanding wind turbines until energy types that work more efficiently with wind can be put in place.
Ault said that backing up wind energy is necessary because electrical service has to be provided continually.
“The product is consumed the moment it is generated,” he said.
Skip Pruss, director of the Department of Energy, Labor and Economic Growth (DELEG), said such concerns can be seen as growing pains as Michigan moves to “a more robust renewable energy future.”
“We’re just in the beginning stages of this overall energy deployment,” he said. “We will work through these sorts of issues with different technologies, and we’re intent on Michigan being the place where those technologies will be developed and deployed.”
Not everyone is as optimistic about Michigan’s wind future, which brings with it the prospect of structures 260 feet tall and higher.
Groups opposed to turbines popping up in picturesque locations around the state began forming after Michigan announced its pro-alternative energy plans. There are currently groups opposed to local wind energy in Allegan, Oceana and Clinton counties and other areas throughout the state.
For example, Clinton County Wind Watch argues that wind power’s stop-and-go nature makes it too unreliable for extensive use.
Natural gas may be a better backup than coal
Pruss said part of the states energy plans involve moving forward with not just wind energy, but also with electricity from sources that complement wind better, such as hybrid combinations that increase the reliability of wind.
“Take a wind farm and hook it up with the latest in natural gas technology, for instance,” he said.
Ault said that natural gas is often suggested in discussions of what to pair with wind.
“If you get a drop in wind, you can start natural gas up pretty quickly compared to coal or nuclear, where you couldn’t,” he said.
Hugh McDiarmid, the communications director for the Michigan Environmental Council, also suggested natural gas as an obvious partner for wind technology.
“It has the advantage of being a little bit less polluting than coal, but it’s also far more adaptable,” he said. “Natural gas plants can peak and stop as needed.”
State needs smarter power grid
Another part of implementing wind technology is improving the power infrastructure in the state, according to McDiarmid.
“The move to renewable energy sources necessitates a smarter and more flexible grid,” he said. “We have to move away from the model of a few massive coal plants and huge transmission lines carrying power to every nook and cranny.”
McDiarmid is referring to an energy grid that can adjust to more than one source of electricity, pay rebates to customers who produce energy that goes back into the system and charge different rates for power used at different times.
Such a grid would be necessary to best make use of the wind-generated electricity, according to Pruss.
Michigan currently generates 140 megawatts of energy from wind a year, and DELEG projects that to increase to more than 2,000 megawatts by 2015.
One megawatt is enough to power 300 homes, according to John Sarver, the head of Michigan’s Wind Working Group.