Weeks of dry weather last fall left Juneau’s Snettisham hydroelectric water supply too low to meet the power needs of AEL&P’s largest interruptible customer.
This may have meant diesel generators were running at Greens Creek Mine, but in the end it could mean higher rates for all customers.
Wet summer months in 2012 raised water levels at Snettisham’s Long Lake and Crater Lake and allowed Alaska Electric Light and Power to credit its customers .07 cents per kWh currently. The summer turned into a dry fall and that credit turned into a charge —one that could cost AEL&P’s average customer an extra $10 a month.
The utility filed for a change to its Cost of Power Adjustment for April 1 through June.
“January and February were warm and wet, so it can be hard for people to remember that October, November and December were cold and dry comparatively,” AEL&P spokesperson Debbie Ferreira said. “The COPA filing for April 1, 2013 is the result of what happened in the fall and early winter and the decision to disconnect our interruptible customers as a result.”
When Juneau’s hydroelectric sources have excess water, what would normally bypass Snettisham’s turbines is used to generate power for large energy users that have alternative power sources such as the federal building, Greens Creek and some cruise ships. Greens Creek was disconnected first on Dec. 1, 2012, with the rest to follow on Jan. 14.
“Turning off a large interruptible customer does have an impact on our … non-interruptible customers,” according to a November AEL&P press release. “The ability to sell surplus energy directly benefits customers by lowering energy costs in the form of a COPA credit. When energy isn't available for surplus sales, then we don't have those surplus revenues to help subsidize the cost of energy to the firm customers.”
Sitka saw low lake levels at its hydroelectric source. The city was forced to supplement its hydro power with about 1 percent diesel power.
Ferreira said a relatively wet and warm January and February has helped lake levels to improve.
“We were able to reconnect our dual fuel customers as of March 1,” Ferreira said. “We expect to reconnect Greens Creek as soon as lake levels allow.”
• Contact reporter Russell Stigall at 523-2276 or at firstname.lastname@example.org.