More than a quarter million Saskatchewan homes and businesses lost electricity on Tuesday as storms in the U.S. Midwest caused computers at the provincial power company to shut down power stations and tie lines.
A spokesman for SaskPower said about 60 percent of the utility’s 440,000 customers in the province lost power early on Tuesday as the storm shut power lines in the Midwest.
That caused computers at the government-owned power supplier to shut down lines connecting the province to North Dakota, Alberta and Manitoba, and to shed load by automatically closing some power stations in the province.
The closed capacity included four units of the 813 megawatt coal-fired Boundary Dam power station and the 218 megawatt gas-fired Queen Elizabeth power station.
“When those units tripped, the computer began shedding customers to balance the load and the demand,” said Larry Christie, a SaskPower spokesman.
Several Midwest power transmission lines went out of service due to storms early Tuesday, including two 345-kilovolt lines in the Minnesota-North Dakota area.
A spokesman for the Midwest ISO, which operates the region’s power transmission system, said there were no widespread outages in the United States and most of the lines, except for one 345-kV line, were back in service in less than an hour.
After the shutdown, SaskPower began restarting its natural-gas and hydroelectric generators to replace the lost power. By 10:00 a.m. ET, 75 percent of the generating capacity had returned to service.
Christie said the utility is reconnecting the affected customers. The city of Saskatoon was nearly unaffected but much of the rest of the province’s cities and surrounding rural areas “were hit very, very hard,” Christie said.