April 1, 2007

Putting together the wind energy puzzle

By KATHY GRAY
of the Chronicle

     Wind is one of the Pacific Northwest’s most abundant resources — except when it doesn’t blow.
     That’s the challenge power managers are trying to address through the Northwest Wind Integration Plan.
     After decades of working with electrical power sources that are pretty much there when they are needed, power managers now have to figure out how to use a resource that’s clean and quick to construct, but doesn’t go by anyone’s timetables.
     “It’s doubly cursed,” said Joe Taffe, power manager for Clatskanie PUD. “It does not blow when the load [demand] is highest — when it’s cold or hot — and it tends to want to blow at night, when everybody is sleeping.”
     Industry reliability estimates vary from 15 to 34 percent of turbine capacity.
That’s not stopping the blossoming wind industry from building more and more wind farms all over the Pacific Northwest — as much as 2,400 megawatts more by 2009 and much more than that on the more distant horizon.
     The Northwest Wind Integration Plan, rolled out March 23, says the Northwest power grid can absorb at least 6,000 megawatts of wind-generated electricity — enough to power five Seattle-sized cities.
     However, that ability comes with a full set of challenges, not least of which is transforming a sometimes power source into a full-time supply to meet power customer demands on a regular basis.
     “Wind, by itself, will not produce a reliable electrical system,” said Tom Karier, co-chair of the Northwest Power and Conservation Council. “There must be some controllable resource behind the wind that can be counted on 24-7, 365 to back up the wind. And controllable resources do have costs. Fortunately, in the Northwest, the costs start out low, integrating with hydropower.”
     Opinions vary on how long hydropower will be able to last as a firming resource for wind.
     At a March 23 press release rolling out the wind plan, statements suggested that hydro’s ability to back up wind could reach it’s capacity within a few short years.
     But Jeff King, one of two main technical analysts on the report, suggests that careful managing of the resource could substantially extend its usefulness to complement wind.
     “Currently, we have plenty of surplus capacity on the system to deal with [peak electrical loads],” King said, “particularly in the hydro system.
     ‘‘[The Wind Integration Steering Committee members are] not all convinced that’s the case, between the councils and utilities. Some of the utilities and Bonneville Power Administration believe we are approaching a capacity shortage situation. When we look at that situation, we’re not in complete agreement.”
Taffe, who has followed the steering committee proceedings, has strong opinions on the issue of using power from dams to firm up power from the wind.
     “Every wind tower you build lowers the efficiency of the hydro system,” Taffe said. It means the dams will be generating power in a less efficient manner. “After a while, you’re not running hydro when you could be and you’re being forced to run it when you don’t want to.”
     King says success of the Wind Integration Plan depends on broad cooperative effort. Several action items within the plan deal with breaking down barriers to cooperation and opening markets to make other existing resources more available for firming up wind power.
     PUDs like Northern Wasco County and Clatskanie have over the years established supply strategies that sharply contradict the one recommended in the wind plan.
     Long before the energy shortages of 2000 and 2001, both utilities believed owning their own power generation was the key to reliable and affordable power.
     “Centralization for efficiency is an oxymoron,” Taffe said. “Lots of players in the market is better. If you have gas turbines, coal generation, hydro — if you have more than one party in there, you’re more likely to get a better product.”
     Taffe also has problems with what integrating wind into the power grid will do to power transmission. Power of any kind must travel from where it is produced, to where it is used over transmission lines.
     “Transmission as the same problem as output: You have to build three times the transmission you’re going to use,” Taffe said. “The investment there is much greater than a baseload coal plant.”
     In other words, transmission has to be built to the full capacity of the wind turbine, even though the turbine may only produce a third that much power. That means building three times as much line capacity as the power likely to be produced — at three times the cost.
     But King, again, believes a variety of strategies can help increase wind’s reliability and reduce needed transmission line construction.
     Spreading wind generation over a broader region can increase capacity: Wind may be blowing in one area when it isn’t in another. Tapping into both can yield power more of the time.
     In terms of transmission, he suggests reducing development costs by creating a slightly less reliable wind delivery system.
     “It may be possible to guarantee an owner of a wind farm they can get power through 98 percent of the time, and be interrupted 2 percent,” King used as a rough example. “By doing that, since you don’t have to guarantee full output, you may only have to reserve 60 megawatts of transmission for a 100 megawatt wind farm.”
     That means a savings in cost.
     “All of those actions should bring down the cost of operational capability somewhat,” King said. “It might extend to 7,000, 8,000, maybe 9,000 megawatts. On our current, conventional course, we would be out of transmission by 2009. But if we implement some of these soft approaches to extending transmission we can extend that.”
     The next two years of planning should give the steering committee a better understanding of its transmission needs, he added.
     King also warned against trying to compare current costs of renewable and fossil-fuel generation in a shifting political and economic landscape.
     Natural gas, for example, experiences big fluctuations in price. Coal may become subject to new governmental controls, including carbon taxes or a mandate that carbon dioxide emissions from the power production process be captured.
     “Talking volatility and uncertainty — that’s a big uncertainty,” King said.
Cost of adding carbon capture equipment to coal plants was estimated at $20 to $25 per megawatt by Northern Wasco County PUD’s consultant Energy Expert Services, Inc.
     That would boost coal power production costs into the same arena as current wind rates. Carbon taxes could have similar results.
     Speaking of costs, King noted that earlier stories from The Oregonian and the Associated Press had incorrectly inflated the anticipated effect on customer rates of integrating wind power.
     The $3 to $7 cost quoted in the stories was the cost to deliver a megawatt hour of power to a utility substation.
     “What customers would see is a fraction of that on their monthy bill, 30 to 60 cents a month is what it would translate at,” King said.