Officials from Northwestern Energy, Montana's largest monopoly utility, say new sources of energy will have to be found in the future as consumer demand increases and parts of the Colstrip power plant start to shut down.
The observations came Friday during an informational hearing Friday in Helena before the Montana Legislature and Public Service Commission.
Colstrip Units 1 and 2 will close no later than 2022 to settle a pollution lawsuit and as a result there will be less “firm power” in the northwestern United States. So-called for its reliability, firm power’s availability doesn’t fluctuate as hydroelectric or wind power does.
NorthWestern’s preferred firm power source is a gas-fired power plant, said John Hines, the utility’s vice president of supply. The company does not consider renewable energy sources like wind and solar power reliable enough, even with battery storage back up.
The company expects the Colstrip power plant, of which it has an ownership share, to be generating power for another 23 years. Several companies, however, disagree with the utility’s assertion that Colstrip will be around until 2042. NorthWestern co-owns the power plant with five other power providers, four of which are preparing to leave the power plant within eight to 16 years.
Several witnesses during the hearing said NorthWestern should also be preparing for an early Colstrip exit. They also questioned the utility’s claims that renewables were unreliable. Concerns about coal power’s contribution to climate change were also repeatedly expressed.
At least a half-dozen coal proponents of Colstrip, including the mayor of the power plant’s namesake community, urged NorthWestern to keep coal in its plans. Sen. Duane Ankney, R-Colstrip, cautioned against replacing coal with natural gas, which he said was vulnerable to disruption as a power source.
Other Colstrip power plant owners have made plans to replace their power with natural gas or renewable energy.