The generators at BC Hydro’s 2730MW GM Shrum generating station (GMS) near Hudson’s Hope in northern British Columbia, Canada, were removed from BC’s grid and later reconnected as part of a test of the utility’s backup generation system.

This was the first time the plant’s generators had been taken off the grid since being commissioned in 1968. On 12 June, the plant’s ten generators were shut down and the plant was isolated from the electric system grid. The plant was then restarted using the four on-site diesel generators as the backup power supply, and successfully reconnected.

For a full 36 minutes, GMS was running entirely on four backup diesel generators, indicating that the backup systems are ready to re-establish generation should the plant become disconnected for any reason. The test was done as part of routine system testing, and adds to the refinement of BC Hydro’s Year 2000 contingency plans. Throughout the test, service to customers was not disrupted.

North American Electric Reliability Council guidelines suggest that offline start capability should be verified at stations that have that capability. BC Hydro’s major generating plants, including Revelstoke, Mica, Keenleyside, Seven Mile and Jordan River have offline start capability.