Drought putting the hurt on local power production

By RICHARD HANNERS

Hungry Horse News

The drought is certainly having an impact on the Flathead Valley's power production and supply, but even if the area generated more power, we likely couldn't get it out of the state, according to industry experts.

In an average rain year, Hungry Horse Dam can put out 428 megawatts of power for only about 91 days. Averaged over an entire average rain year, the dam can generate about 60 to 80 megawatts. This year the dam has produced as little as eight megawatts of power.

The Flathead Valley load is about 120 to 140 megawatts, according to Flathead Electric Cooperative spokesman Mike Radel. At full production, the Columbia Falls Aluminum Co. smelter uses about 345 megawatts. In an average rain year, the Flathead Valley would need to import about 150 megawatts to meet these loads.

Although the dam has 428 megawatts of installed capacity, its primary function is water storage for downstream dams, according to facility manager Ralph Carter.

According to Carter, a typical year begins with a January 1 runoff forecast from the River Forecast Center, which calculates the desired reservoir level by April 10. A winter cold spell might force dam operators to increase flow in order to put out additional electrical power. The reservoir level is maintained until May 1, at which time it begins to fill for flood control purposes.

This year's drought conditions have significantly impacted Hungry Horse Dam's power generation. Carter said the dam generated about 80 megawatts from January 1 through April 15, except for two weeks in February when power increased to about 160 megawatts. From April 15 through June 8 the dam generated only eight megawatts, not much more than the PacifiCorp dam in Bigfork.

The Hungry Horse Dam generators are also used to correct power factor problems at this corner of the Pacific Northwest power grid. A generator is run as a synchronous motor, and the turbine spins with no water in the pipe to help the system run more efficiently.

Northwest Montana must then look to other sources for its power and is supplied by three other sources.

The oldest of the four sources is a 100-kilovolt transmission line built in 1947 to bring power from Kerr Dam to the Hungry Horse Dam construction site. This line has numerous bottleneck problems stemming from its non-standard voltage and the World War II surplus cable used to build the line.

Maintenance crews use thermal imaging equipment to identify sections of transmission lines that are running too hot. The overall capacity of the line is rated by the weakest link.

The third source of power for the Flathead is the 230-kilovolt Hot Springs line, which brings in power from the rest of the Pacific Northwest grid. It was built at the same time as the Hungry Horse Dam.

The Hot Springs substation is connected by a 500-kilovolt line to the Taft substation below Lookout Pass, which is part of the big Colstrip-Spokane transmission line used to export power from Montana to the Pacific Northwest grid.

The fourth source of power for the Flathead is Libby Dam, which began producing power in 1974. According to project manager Mick Shea, the dam has 600 megawatts of installed capacity, but averages about 300 to 350 megawatts in an average rain year.

Like Hungry Horse Dam, Libby Dam is also used as water storage for downstream dams, and the water is used 16 times before reaching the ocean. This year drought has reduced power generation at Libby Dam to about 70 megawatts since January 1.

Power from Libby Dam comes to the Flathead Valley by a 230-kilovolt line that meets the Hot Springs line at the Flathead substation next to Semitool Inc. on Reserve Street. Both lines continue to the Con Kelley substation, next to CFAC, where they join a line from Hungry Horse Dam.

Libby Dam is also connected to the Pacific Northwest power grid by a 230-kilovolt line running to Noxon Rapids and then on to Hot Springs, but because of several investor-owned hydroelectric dams connected to that line, power from Libby Dam tends to avoid that route and instead runs to Hot Springs via the Flathead substation.

A 115-kilovolt line connects Libby Dam with Troy and the northern Idaho communities of Bonners Ferry and Sandpoint, where significant load growth over the past decade has driven the need for upgrading this line. This line eventually connects to the Pacific Northwest grid in Spokane.

In the political arena, critics have argued that Montana has about 3,200 megawatts of installed electrical generating capacity but only about 2,000 megawatts of in-state load, leaving about 1,200 megawatts of power for export.

In short, they claim that in a regulated market Montana shouldn't be as impacted by power prices because Montana exports more power than it can use - even in a drought year.

Gov. Judy Martz has often argued the cure for Montana's power woes is to create more generation, but getting it out of the state would actually prove fruitless with our current transmission system, according to industry analysts.

Since World War II, transmission lines were built to connect major generating facilities with major load centers but, just as happened with power generation, over the past 20 years construction of new lines has lagged behind growth in overall load and by new load centers.

Improving or constructing new transmission lines is both expensive and politically difficult. New lines can cost as much as $1 million per mile. Increasing capacity usually means increasing transmission voltage, not stringing new cable, which can require costly new transmission and substation equipment.

Transmission lines cross multi-jurisdictional lines, and construction of new lines usually requires a full-blown environmental impact statement. Project planners must address concerns and opposition about environmental impacts, and rights-of-way must be purchased.

There are also local problems caused by the uncertainty of the aluminum industry and the CFAC smelter.

The future status of the aluminum plant will affect transmission line improvement projects, analysts say. Repeated warnings over the past two decades by aluminum plant management that the smelter might close due to high power costs made long range power planning difficult.

During an average rain year with the aluminum plant off line, about 280 megawatts of power from Libby Dam could be transmitted out of the Flathead via the Hot Springs line. The Hot Springs line, however, is not large enough to handle the full capacity of Hungry Horse and Libby Dams if the aluminum plant is off line.

Furthermore, the Colstrip-Spokane line may not have sufficient capacity for exporting this additional power out of Montana to the Pacific Northwest grid.

If Flathead Valley load continues to grow, and the aluminum plant goes back on line at full capacity, the capacity of the Hot Springs line will need to be increased to bring additional power into the valley.

Bottlenecks in transmission lines feeding the Flathead Valley were addressed by the Flathead Valley Reinforcement Project, which was shot down twice during the 1980s after opposition was raised at public hearings. Forecasted load growth in the valley slowed down by the late 1980s, mostly a result of conservation efforts. Since then, load growth has inched its way up closer to the capacity limits of the Hot Springs line.

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-- Martin Thompson (mthom1927@aol.com), June 21, 2001