After 53 years of continuous service, the turbines at Sitka’s Blue Lake Hydro plant are quiet.
Walt Dangel, one of the original powerhouse operators at Blue Lake, threw the switches turning off the plant in a small decommissioning ceremony Monday morning (8-18-14). Dangel was assisted by Frank Rogers, Sitka’s senior plant operator.
The two old turbines produce a combined 6 megawatts of power. They’re being replaced by three new turbines that will produce 16 megawatts.
For about the next two months, Sitka will get its electricity from the Green Lake hydro plant and the backup diesel turbines on Jarvis Street. All drinking water in the community is now drawn from a $4-million temporary filtration plant on the Indian River. The shutdown is to allow workers to complete the new penstock at the Blue Lake dam, connecting the expanded dam to its new powerhouse.
For the next 63 days, the city has asked residents to conserve both water and electricity. The traffic signal symbol used by the electric department to indicate the availability of power went from green to red overnight. As the weather cools down, residents are being asked to use alternative heat sources, such as oil or wood, if possible.
The city also warned Sitkans that they may see yellow or discolored water coming out of the tap, especially after a heavy rainfall. The color comes from higher-than-usual amounts of organic material being washed into Indian River, but the water is safe to drink. Trying to flush the lines won’t clear the water. In fact, excess water consumption only strains the capability of the temporary plant at the river.
So what happens in 63 days? Sitka utility director Chris Brewton says there should be enough water in Blue Lake to commission the first of the three new turbines. Then, over the next two weeks to a month, they’ll bring the two others online.
Brewton says it’s going to be bumpy for a while, as engineer work out the bugs in the new powerhouse. But not as bumpy as the commissioning of the 18 megawatt plant at Green Lake in 1982. Power outages were so frequent at the time that the Alaska Pulp Corporation Mill generated its own electricity for several months.
The issue is the size of Sitka’s electric grid. As the new turbines are powered up, small problems can force the shutdown of the whole system.
And a final, small upgrade that’s been overshadowed by all the major work at Blue Lake: the electric department has replaced the 670 kilowatt turbine at the Sawmill Creek campground with a bigger, 1 megawatt unit.
Brewton says the old turbine — just like the Blue Lake units — is still in good shape. He says, “We’ll shrink wrap it and try to sell it on eBay.”