The Alaska Electric Light & Power Co. is projecting that it will be able to drain its Bart Lake reservoir to fix leaks this spring while still meeting summer power needs.
That includes providing surplus energy to customers such as Green Creek Mine and cruise ships, said Scott Willis, the utility's power generation manager.
"Right now, it looks like we are in pretty good shape," he said.
AEL&P plans to drain Bart Lake, part of the Lake Dorothy Hydroelectric Project south of town, beginning in March. Then it will install an impervious membrane along the shore, hoping to fix troublesome leaks that have concerned the Federal Energy Regulatory Commission.
The utility had also considered drilling and grouting to find and seal leaks, but is now planning to go with the installation of the membrane instead, Willis said. FERC is currently reviewing that plan.
When the Lake Dorothy project went on line last fall, it added 20 percent to the city's hydroelectric production capability. Most of the remainder of the power comes from the large Snettisham Power Project south of Lake Dorothy, but also includes several relatively small facilities in the area.
With the loss of power from Lake Dorothy Hydroelectric Project during the draining of Bart Lake, AEL&P officials had originally been worried they might not have enough surplus power for the mine or cruise ships, but officials weren't expecting to need backup diesel generators.
"Current projections are that we will have enough water at Snettisham to continue all our power deliveries (including to Greens Creek mine) through the summer, even though Lake Dorothy will be off line," Willis said.
Most of the water that powers the Lake Dorothy Hydroelectric Project is held in Lake Dorothy itself, but it must flow through the small Bart Lake before it is fed into the hydroelectric turbine on the shores of Taku Inlet.
When Juneau has surplus power beyond the city's own needs, the excess can be sold to the mine and cruise ships, reducing their need to generate their own power with diesel, lessening pollution and cutting their cost of operation.
However, unusually cold or dry weather could still cause a shortage that would require curtailing surplus sales, Willis said.
Contact reporter Pat Forgey at 523-2250 or email@example.com.