A 740 MW coal-fired power plant that tripped offline July 1 will have to stay in a shut-down state for at least six months, according to its owners.
PPL Montana and NorthWestern Energy said their co-owned Colstrip Power Plant, east of Billings, Montana, sustained damage to its rotor assembly (also known as a stator). The damage was consistent with a ground fault. Plant operator PPL Montana has plotted a six-month repair schedule, according to Power Engineering.
The plant employs about 360 people and is owned by PPL Montana, Puget Sound Energy, Portland General Electric, Avista Corp., PacifiCorp and NorthWestern Energy.
Under a reciprocal sharing agreement, each party equally shares costs to operate, maintain and repair the unit as well as its allocation of the output from Unit 3. The repairs are expected to cost $30 million and NorthWestern’s share will be about $4.5 million.
PPL has property damage insurance and may file a damage claim. If they do, the deductible would be $2.5 million. NorthWestern Energy has already purchased replacement power. Unit 3 continues to operate at full power.