Anchorage municipal officials and regional utility managers practiced for an emergency winter gas supply and electric power disruption Nov. 6.
"We took the system all the way down from green and yellow to condition red," after which utilities would trigger rolling power outages, said Anchorage municipal manager George Vakalis, who managed the exercise.
Conditions yellow and red are where the utilities ask consumers to cut back on energy use, condition red being more urgent.
If the voluntary response isn't enough, the electric utilities will impose planned outages to preserve gas, mainly aimed at keeping the regional gas distribution system intact.
Utility and municipal officials say a major midwinter gas supply and power disruption is unlikely, but there's enough of a chance that they don't want to take chances, which is why contingency plans are being put in place and practice sessions held.
The problem is that Southcentral Alaska natural gas wells that fuel electrical generation and provide heat for buildings are producing less these days because the 30- and 40-year-old gas fields are being depleted. The ability of aged gas wells to meet surging demand during very cold weather is now strained, utility officials say.
Geologists say the Cook Inlet region has more gas and is actually under-explored, but there hasn't been enough new drilling to replace reserves in recent years for a variety of reasons, including high costs and the inability to get gas sales contracts approved by the Regulatory Commission of Alaska, although the commission recently approved two gas contracts.
The situation is critical enough, however, that there is serious concern that a prolonged cold snap, combined with unexpected equipment failure, could create shortages of gas in very cold weather, just when it's really needed. It almost happened in the past two winters, in fact.
Vakalis said the scenario practiced Nov. 6 involved an assumed equipment failure at the Beluga gas field, which mainly serves Chugach Electric Association and Municipal Light and Power, followed by a mechanical problem at the Steelhead platform in Cook Inlet, which supplies gas to Enstar Natural Gas Co.
The event was assumed to happen at peak periods of power use, from 5:30 a.m. to 8 a.m. or 4 p.m. until 7 p.m., he said
Two almost simultaneous mechanical failures like this could cut about a third of the regional gas production, or about 125 million cubic feet off the 403 million cubic normally available to the utilities during cold weather.
Vakalis said he and senior utility officials developed the situation and presented it to a team of operators from Chugach, ML&P and Enstar, who were not aware of the scenario.
Matanuska Electric Association sent observers to watch the session and also participated. Managers from the three major gas-producing companies, Marathon Oil, Chevron Corp. and ConocoPhillips, were on hand to answer questions.
Utility operators, who frequently work together on real disruptions, went through the steps they would take to deal with the emergency.
Condition yellow was triggered where the utilities took steps to cut back on the use of gas. In the exercise, Chugach Electric asked the city of Seward to fire up standby diesel generators so that Chugach could stop sending power to Seward.
Chugach also asked Golden Valley Electric Association in Fairbanks to send power down the electric Intertie that connects Interior and Southcentral Alaska.
Municipal Light and Power fired up diesel standby generators in two of its power plants in the exercise, to cut back on use of gas.
The Alaska Energy Authority was asked to increase power output at the Bradley Lake hydro facility near Homer.
A community alert procedure was triggered, through radio and television announcements, to ask consumers and building operators to cut back energy use, to turn thermostats down, adjust hot water heaters and avoid doing laundry.
In the exercise, the situation worsened and went from condition yellow to condition red.
Some 22 middle and high schools in the Anchorage School District are equipped with diesel-fired heating and power generation, and these facilities could be fired up in such a situation.
Hospitals and other institutions with standby power would be asked to switch their systems on. Many commercial buildings in the Anchorage area have standby power, and building owners would be asked to trigger those.
City officials are now working on an inventory of buildings with standby power and heat. This could be useful in a real emergency, Vakalis said.
In the exercise, Vakalis and other managers of the practice session then said voluntary steps weren't enough and pushed the session beyond condition red, where rolling blackouts are instituted.
"We practiced how we would do this and what we would do to assist neighborhoods," Vakalis said.
For example, police would be on extra alert to prevent crime in darkened areas.
Chugach public affairs manager Phil Steyer, who participated in the session, said the outages would be of short duration, 20 to 30 minutes, not long enough to let a home or building cool to uncomfortable levels.
After the exercise, a follow-up meeting was held Nov. 13 to discuss lessons learned.
John Sims, Enstar's customer service representative, sat in on the meeting and said there was discussion of one possible weakness in the emergency plan, whether there would be enough diesel and fuel trucks available to keep standby generators and heaters supplied.
Jim Posey, general manager for ML&P, has said his utility does have standby diesel generation, but keeping that running for an extended period would require one fuel delivery an hour to each plant.
The utilities have been working together for some time on planning for major gas supply disruptions, a move encouraged informally by the Regulatory Commission of Alaska after the near-miss on a major gas supply disruption last winter.
In that situation, a compressor in the Beluga field went down in very cold weather. Fortunately it was a weekend, when power demand was relatively low, and Enstar Natural Gas has taken steps to pressure up its lines in anticipation of a heavy draw Monday morning.
When the compressor failed and pressure dropped off in a pipeline coming from the Beluga field, there was enough gas "packed" in the lines that Enstar's system was in no danger, and things returned to normal when Beluga field operators go the compressor working again.
The event was enough to trigger real concern among the utilities as well as the regulatory commission, which held an unusual Saturday informational hearing to query the utilities on the status of their contingency planning.
The one-third gas supply disruption scenario practiced Nov. 6, considered the most likely kind of emergency, would require electric utilities to cut back their use of gas by 75 percent to preserve gas for Enstar's system, which would cut back only 10 percent.
Vakalis said it's vital to preserve gas in Enstar's system because if the gas pressure falls too low gas furnances automatically shut off, and have to be individually reset. Such an event would leave buildings without heat, frozen up for weeks or even months.
Enstar says it has identified teams of technicians among its sister utilities that could be moved quickly to Anchorage to supplement the utility's own workers, but such an event would clearly be a disaster.
Tim Bradner can be reached at
tim.bradner@alaskajournal.com.
