Consumers in Anchorage cut power by 1.5% in voluntary drill

Electrical consumers cut power use by 1.5 percent in a voluntary two-hour drill in an early-evening peak demand period, Anchorage Mayor Dan Sullivan said Nov. 5. Regional utility and city officials were testing consumer response to requests to voluntarily reduce power use if an emergency were to occur.

Electric utilities serving Anchorage depend on natural gas-fired generation for 90 percent of their generation, and there are concerns that shortages of gas during winter cold snaps, when demand outstrips local gas production, could impair power production.

“The 1.5 percent reduction we measured equates to approximately 1 billion cubic feet,” of gas not consumed, Sullivan said in a statement.

The drill was held in the evening hours of Oct. 31. The reduction of 1.5 percent was less than the savings achieved in similar drills over the last three years, which were estimated at 2 percent to 4 percent. Chugach Electric Association Spokesperson Sarah Wiggers said the smaller reduction was likely a result of somewhat colder weather this year compared with days on which the drill was held in previous years, which would have discouraged voluntary reductions.

Also, it was Halloween evening, a time when many homes were lighted to ensure safety for children.

Utilities in Southcentral Alaska use about 70 billion cubic feet of gas yearly, but the depletion of gas fields and declining daily production of gas wells has led to estimates that the region will be short of overall gas supply by 2015, which will require gas to be imported as LNG or compressed natural gas.

The shortfall in daily production during cold weather could cause an emergency, Sullivan said. If there is a shortage the gas that is available will be diverted to Enstar Natural Gas Co., the regional gas utility, from the electric utilities.

Chugach Electric Association and Anchorage’s city-owned Municipal Light and Power, the utilities serving Anchorage, have some capability to use oil-fired power as a backup and to bring power from Golden Valley Electric Association in Interior Alaska if needed, but if those are insufficient the utilities may institute rolling blackouts.

The focus on preserving Enstar’s supply is because gas delivered by the gas utility is used for space heating across Southcentral Alaska and a shutdown of even parts of Enstar’s system could lead to massive freeze-ups of buildings during cold weather.

11/08/2012 - 8:35pm