So much electricity flooded Pacific Northwest powerlines last spring – thanks to rainy, stormy weather powering hydroelectric and wind turbines – that this spring, a federal agency wants the option of turning off wind turbines to keep the system from overloading.
The Bonneville Power Administration – which sells power from its hydro dams in the Columbia basin and regulates the power grid in the Pacific Northwest – has written a new policy that would allow it to shut down investor-owned wind turbines if high winds and high water produce more power than people need.
Bonneville has been working on the proposal since last June, when for three weeks the electricity produced in the Pacific Northwest exceeded the demand thanks to storms that increased the flow of water in the rivers and kept windmills spinning. To deal with the excess, Bonneville offered free hydropower to area natural gas and coal-burning utilities if they would temporarily shut down their air-polluting power plants.
Wind power generators balked at accepting that free power and putting the brakes on their windmills, because that would have deprived them of federal and state incentives, money they only get when the windmills are turning.
This year, Bonneville wants the option of shutting down wind and says its power contracts allow it to do so. It says that would only be done in rare cases and when other measures, such as briefly shutting coal and natural gas plants, won’t balance the system.
“It is an option of last resort,” said BPA spokesman Doug Johnson.
But Bonneville’s idea has drawn criticism, both from renewable energy supporters who want to see more wind power on the grid, and from environmental advocates, who say that if the BPA has too much power, it should reduce use of hydro turbines and instead spill unneeded water over dams in order to help imperiled fish species. Juvenile salmon and steelhead swimming downstream survive a trip over the dams better than going through power turbines.
A public comment period about the new policy closes today. Bonneville expects to finalize its decision by early April.
Wind power growing
The new policy is being discussed at a time when wind power is growing in the region – much faster than anyone predicted.
February marked a milestone for wind in the Pacific Northwest. It was the first time wind power – for a brief period – exceeded 3,000 megawatts on the BPA transmission grid. That’s enough to power a major U.S. city.
The agency expects such growth to continue with between 5,000 and 6,000 megawatts of wind power available by 2013, years ahead of earlier estimates.
Wind power’s growing presence on the grid is a challenge for the BPA. In addition to overseeing power generation on the federal hydro projects, the agency is also the “balancing authority,” making sure that its transmission lines have enough electricity to meet the need but not so much that it overloads and damages the system.
BPA’s transmission lines also serve other power generators in the region, from big for-profit utilities like Pacific Power to small public utility districts.
Wind power requires careful managing because it’s so variable. A storm – sometimes forecasted, sometimes a surprise – can boost electricity production suddenly and then just as suddenly die down.
Last year, on May 19, wind turbine-generated power ramped up 1,580 megawatts in a single hour, 756 megawatts of that in just 10 minutes, BPA records show. A couple of days before that, wind-generated power dropped by 1,160 megawatts in a single hour.
Bonneville has to be ready to reduce power from other sources when wind power soars, and quickly refill when wind suddenly drops off. Typically, Bonneville balances the load with hydropower, because the region’s gas, coal, and nuclear generators, known as thermal generators, need either advanced notice or more time to ramp up or down.
The other option, shutting down hydropower and spilling water over the dams instead of running it through the turbines, won’t get Bonneville the rest of the way to a balanced system because there are environmental curbs to how much water can be spilled, Johnson said.
Too much water spilled over the dams increases dissolved oxygen in the water to the point that it can kill fish, he said.
So, the BPA is looking at intermittently cutting back on wind, Johnson said.
“There’s a limit to the amount of water we can spill,” he said. “If we reach a point where we can’t give away the energy and meet the requirements of the fish, we will then tell the wind folks, we’ve got to curtail your production.”
Fish advocates skeptical
But fish advocates, who have sued Bonneville for failing to do enough to help fish that are at risk of extinction, are skeptical.
It was only under court order that Bonneville increased the amount of water it spills over the dams to help juvenile fish migrating downstream, said Nicole Cordan, an attorney with Save Our Wild Salmon, one of the groups that sued in a case that is still being litigated.
Young fish survive a trip over the dams much better than through the turbines or regulating outlets on the rivers, Cordan said. While fish can be harmed by too much oxygen suspended in the water, biologists are finding that they can tolerate more than initially thought, she said.
“There is a very small grain of truth that (Bonneville) is now trying to exploit, which limits spill for salmon,” Cordan said. “What all the science is showing is that more spill is better for fish,” she said.
Fish biologist Margaret Filardo, who works at the Fish Passage Center, an agency established by the Northwest Power Planning Council to analyze and report on the status of endangered fish in the Columbia River, says there’s wiggle room to go above the limits that are now in effect.
Current science suggests that fish do fine even when dissolved oxygens exceed the equilibrium point by 20 percent, the limit set by the state. Filardo says that fish can handle higher levels, say, 23 percent over equilibrium, overnight or for a couple of days. Dissolved gas levels of 25 percent more than equilibrium over the course of several weeks might pose a problem for fish, she said.
“I don’t think short-term exposures are particularly detrimental,” she said.
Cordan points out that BPA has exceeded those limits on many occasions without facing any fines or sanctions from the state Department of Environmental Quality.
Power rates won’t fall
Meanwhile, those who favor more renewable energy don’t want to see wind curtailed when too much electricity is being generated, said Rachel Shimshek, executive director of Renewable Northwest Project, a nonprofit group that promotes renewable energy. The region’s wind farms are owned by a range of entities, including private investors.
Wind represents just a small sliver of the power supply that the BPA manages, Shimshek said. During the first 17 days of June last year, when the BPA faced the spectre of too much electricity, wind represented just 7.3 percent of the total. Natural gas, coal-fired and nuclear plants were producing 6.9 percent while the hydro-turbines were producing 85.5 percent.
Load imbalances – times when there is more power than communities need – aren’t a new phenomenon for Bonneville, Shimshek said. “Bonneville admits that they have had a load resource imbalance 30 percent of the time since the creation of the BPA system,” she said.
“We are urging Bonneville and all the utilities to cooperate in first reducing the amount of thermal generation and to actively explore a variety of other preventive strategies,” she said.
Bonneville says it’s doing just that. The area’s biggest wind generator, Iberdrola Renewables, an international company with offices in Portland, announced last September that if there’s too much wind, it would temporarily shut down the gas-fired generators that it also operates.
Some coal and gas generators have agreed they’ll take free hydropower and shut down their systems when there’s too much electricity between May 1 and June 30, Johnson said.
But those measures might not be enough, and Bonneville wants the ability to curtail wind in worst-case scenarios.
Some wind generators have suggested that Bonneville sweeten the deal by paying them the federal and state incentives they currently receive for generating power.
Bonneville won’t do that, Johnson said.
“We will not pay people to take our power,” he said.
Shimshek thinks Bonneville should put together a steering group to come up with a broader list of solutions.
“It’s a much more productive path,” she said. “This proposal will likely end in litigation, and that won’t help anybody.”
What does all this mean for the pocketbooks of ratepayers whose local utilities – such as Eugene Water & Electric Board, Lane Electric Cooperative and Emerald Peoples Utility District – have long-term contracts to buy BPA power?
The excess energy during one part of the year will not translate into lower monthly bills for consumers, Johnson said. Bonneville still needs all the money it gets from local utilities, in order to upgrade its aging hydropower infrastructure.
“We’ve got this convergence of a drop in secondary revenue (from sales of power on the open market) and an ambitious program to keep these assets in good shape,” Johnson said.
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