Winter is Here, but that Shouldn’t Be a Power Threat
North American winters are harsh and unforgiving. Canadians experienced the coldest February on record in 2015 with wind chill temperatures dropping below -40°C (-40°F) in Toronto. Things typically are not much better south of the border, where Chicago residents recently were advised to “stay inside” when the wind chill caused the temperature to feel as cold as -30°F (-34°C).
When heavy ice storms occur, it’s not unusual for the lights to flicker, dim, and then go out. Southern Ontario saw 75,000 people without power last March when freezing rain and high winds caused a buildup of ice on trees, resulting in them crashing down, taking the power lines with them.
As a result of such occurrences, utility customers are left in the dark, literally. Their heating system also does not work, and for many customers there is no way to heat water, cook food, or check on the status of the problem. Meantime, businesses shut down because they cannot keep production up, costing them perhaps thousands in lost revenue.
Moreover, all drivers, already facing arduous conditions, now face a new challenge: the traffic lights don’t work. Accidents are more likely to occur, and emergency vehicles have difficulty maneuvering the traffic jams so they take longer to arrive to find and fix the problem.
And this can go on for hours.
This is a scenario with which the remote community of Field, British Columbia, had become all too familiar. Nestled in the Canadian Rockies and located 55 kilometers from the nearest substation, the 200 or so residents relied on one 25-kV distribution feeder for their power supply. The feeder is not only remote, but it also runs along a railway line, making access and repair work difficult, time consuming, and expensive.
The climate also caused the vulnerable feeder to often experience faults, and the remote location meant power restoration took longer than average, leaving the residents without power for extended periods of time.
BC Hydro, the local utility, refused to accept the status quo and implemented an innovative energy storage solution to swiftly respond to faults. When demand is low, the battery charges. When a fault occurs, a fault-interrupter detects and isolates the upstream fault while signaling the energy storage system to start discharging battery power, a seamless process that takes seconds. During an outage, the battery discharges, keeping the lights on in Field and providing approximately 7 hours of uninterruptible power to the entire town.
In fact, in the first six months of system operation, six major events occurred, ranging from trees falling on the lines to broken poles. Each time, the system operated flawlessly to avoid an outage, supplying Field with battery power for a combined 40 hours throughout these periods. Since going live, the system has prevented power outages caused tree falls, car accidents, avalanches, and fires for a combined 126 hours. The longest single duration was 22 hours.
Today, when a tree falls on the lone feeder, the residents of Field count the seconds instead of hours until the lights turn back on. The line crews have enough time to organize and execute an efficient repair, and life goes on: heating systems kick back in, the water can be boiled, and cups of hot chocolate are made all over the town.
January 12, 2017