By Andrea Arnold
Power outages are a part of life in the Robson Valley. The valley is powered by a single line that originates from the south-east. The BC Hydro line that travels from the Valemount substation through to Dome Creek is a 150km-long line exposed to the elements, both natural and man-made, creating more chances for damage causing a power outage. The distance between Valemount and the substation is minimal, lessening the possibility of an outage due to line damage.
Sometimes, the issue is bigger than just a problem on the line. During the 2003 McLure/Barriere wildfire many valley residents were left without power for up to a month. It became clear to BC Hydro that a more reliable solution was needed for McBride, the largest populated area towards the end of the line.
In October of 2010, McBride was equipped with back-up diesel generators that have the capacity to power an approximately 20km “McBride Island” zone (from the Holmes River to Lamming Mills, including much of Mountain View Road) for several weeks, and longer with a reliable source of diesel, according to BC Hydro Northern Community Relations Manager Bob Gammer. These generators have a sensor that causes them to turn on within seconds of registering an outage. Of courseâ€as it often goes with technologyâ€there is sometimes an internal mechanical issue and delay in start-up, as on December 19, 2020.
If the issue relates to lines or poles within the McBride Island zone, an override prevents the diesel system from activating to allow crews to fix the outage problem. By keeping power off, crews can safely make the repairs needed, and also prevent serious events such as fire or accidental electrocution to Hydro workers or people in the vicinity of a damaged wire.
If the outage issue is on lines or poles between Valemount and the Beaver River, however, the circuit breaker at the Holmes (Beaver) opens, followed in kind by the one at Lamming Mills and power is restored to those inside the McBride Island thanks to the generators. “When the fault is restored, there is a brief outage when the diesels are shut down, and then the Beaver circuit breaker is closed and power restored,” said electrician John Wheeler.
IPPs
In addition to the diesel generators, there are several Independent Power Producers (IPPs) scattered around the valley that can sometimes help supply power when there’s an outage. These run-of-river projects supply power to the BC Hydro grid from the force of moving water. Wheeler does contract work for five of the six IPPs in the area and works in cooperation with BC Hydro to help service reliability
If an issue East of McBride is expected to cause an extended outage, BC Hydro can contact the IPP’s on the west line to block them. The system at Lamming Mills will then be closed, allowing power from the diesels to travel further west to Dome Creek/Crescent Spur. This has to be a carefully communicated and executed scenario as it is not allowable for the IPPs (other than Castle Creek under specific conditions) to be online at the same time as the diesels.
Wheeler explained that usually, IPPs feed into the system when their points of connection to the BC Hydro system are live. “BC Hydro must specifically contact the operators to ensure the plants remain offline,” he said.
Planned Outages
Planned outages are sometimes needed to perform work on BC Hydro’s transmission or distribution systems. During a transmission line planned outage (on the line between Kamloops and Valemount), or a planned outage to equipment in the Valemount Substation, BC Hydro works with Wheeler to create a plan that allows the whole valley to become an “Island” with IPPs providing the full power load, assuming there’s a high enough water flow.
“At the planned outage time, all the IPP’s will be configured as needed to meet the load, and the Castle Creek Plant will be switched to a master control mode so that it can manage the varying system loads,” said Wheeler.
BC Hydro opens the circuit breaker at the Valemount substation, and the IPP’s provide normal service to the whole valley from Albreda in the south, Mt. Robson in the east, and Dome Creek in the west. The switch to valley wide “Island” status is often unnoticed, but the changeover back to the grid sometimes involves a brief outage.
This procedure can also be used if an unplanned event occurs. “This can happen if a storm damages the line and it is not accessible to repair, as some parts of the transmission system are only accessed by helicopter.”
If it becomes apparent the outage will be a long one, and the IPPs have enough water to meet the demand, the entire Valley can go to “Island” status until the system has been repaired. The transition has to be carefully planned out to provide a safe switchover; as a result customers do experience a disruption until the switching process is completed.
The Stats
A report from BC Hydro shows that the average total outage duration per customer in the Robson Valley, per year, has gone from 10.4 hours/year in 2016 to 6.5 hours/year in 2020. Gammer says that along with the generators and IPPs, the improvement comes from vegetation clearing under and alongside the lines, and advances in equipment. Issues can be located faster and monitored carefully.
“The severity and location of the damage determines the amount of time it takes to restore service,” he said. “Some of the areas are not easily reached, resulting in longer repair time.”
Locations that have repeat issues are reported to engineers who look for ways to improve accessibility or even relocate power poles and lines to enable faster repair.
As BC Hydro works to improve service, they also encourage customers to understand what they can do in their homes to prepare for the times there is a service interruption. On their website they explain how to be self-sufficient for a minimum of 72 hours through a detailed checklist. The most important thing is to be organized, know where your emergency kit is and to keep it stocked, up-to-date and accessible.
Helping spot a problem
“When people see an issue, such as a tree on a power line, we ask that they call 1-800-BC HYDRO (1-800-224-9376), and report the location and as much detail as they can safely provide,” said Gammer. “Getting accurate information will help crews locate the fault (that is causing a power outage) faster and speed up the repair process.”
It’s also helpful if people know what to look for. There are many trees on wires along the highway between McBride and Prince George, but not all are BC Hydro lines, some are TELUS.
“Hydro poles are the taller ones compared to TELUS,” Gammer said. “The thin, bare wire on the very top of those poles is the electrical conductor
In cases where there are multiple lines on a pole (BC Hydro and TELUS), the power lines are always located on the top and TELUS lines are the lowest. If you see something on a Hydro line, please call BC Hydro. If you see a downed line, it is important to stay clearâ€10 metres at leastâ€and report it as soon as possible by calling 9-1-1.
Contact Andrea at [email protected]
