A more volatile climate. Closing coal plants. Loss of hydro power. Will there be adequate resources if temperatures hit 115 degrees in Colorado and beyond?
by Allen Best
It got hot last summer across Colorado. Denver had 67 days of temperature that hit 90 and above, the third most in a century and a half of thermometer-watching.
What if it got much hotter, say 115 degrees for several days? And instead of being relatively isolated, like the Pacific Northwest oven in June 2021, this heat dome caused air conditioners from Sacramento to El Paso to Colorado Springs to work overtime?
Would there be electricity sufficient to meet the demand in Aspen, Boulder, and Sterling? Grand Junction, Alamosa, and Steamboat Springs? Amid this record heat, would Coloradans be left without electricity as occurred with the rolling blackouts in California during 2020?
Last week, on a day when the thermometer in Denver struggled to get above freezing, members of the Colorado Public Utilities Commission started hashing through this and other questions related to what utility planners call resource adequacy. They indicated they’re most focused not on the longer term. Instead, they’re thinking about 2025 and 2026.
Utilities have always tried to maintain reserve margins of generating capacity. Most use a standard expectation of not meeting demand just one day in 10 years.
Now we’re rapidly closing coal plants. They were never entirely reliable, as witnessed the many times that Colorado’s youngest coal plant, Comanche 3, had to suspend operations in recent years. But they did run when on those rare times when the prairies become still, unruffled by the usual winds.
February 2021, during Winter Storm Uri, was one of those times of quiet. Colorado’s second largest utility, Tri-State Generation and Transmission, burned fuel oil to generate electricity.
Natural gas plants would seem to supply an answer, and Xcel Energy, Colorado’s largest utility, plans to add generating capacity in the next few years. But Nicholas Garza, a researcher in the emerging issues division of the utilities commission, told PUC commissioners that natural gas has its own vulnerabilities in such times, as was evident in Texas during Uri. Xcel also had its natural gas problems during that storm.
The warming climate has also become more volatile. This poses a challenge to existing electrical infrastructure, both renewables and fossil fuels.
In time, with new technological development and production at scale, some of the limitations of renewables may be addressed with longer-term storage. Construction of transmission to knit together diverse areas of the country may also diminish the threat of power outages. It’s extremely rare that it can be hot as Hades in both Seattle and Salida.
For now, though, state regulators are sweating about summer heat. Wildfires could exacerbate the situation. A study by researchers at the National Center for Atmospheric Research found that California’s wildfires in September 2020 darkened the skies so much that solar power production during peak hours was slashed by 10% to 30%. Read more here.
Then there’s hydropower. It constitutes between 20% and 25% of the generating capacity in the West. But, of course, the giant reservoirs in the Colorado River as well as their smaller siblings in the headwaters —think Flaming Gorge and Blue Mesa—keep dropping in water levels.
“Some hydrologists are saying that Hoover and Glen Canyon could get below (minimum power pool) by 2026 or 2027, and that takes 8 to 9 gigawatt-hours out of the wholesale market,” said John Gavan, a PUC commissioner.
Utilities such as Xcel Energy mostly have their own generating assets and also contracts for firm deliveries through power-purchase agreements. But a growing number of utilities are buying growing quantities of power from the wholesale power market. This assumes available power that is usually there but not guaranteed.
This concerns Gavan. With Colorado’s two investor-owned utilities and with Tri-State, Colorado can look over their shoulders about reliability. It lacks that oversight of municipal utilities and Colorado’s four independent. Another cooperative, United Power, the second’s largest, also has vowed to become independent.
Guzman Energy and Crossover Capital have emerged as private—and unregulated—suppliers.
Gavan suggested that legislation being readied may attempt to impose oversight of this growing component of the electrical market.
Another element of this story is the coming demand for electricity for transportation and to replace fossil fuel combustion in buildings. Eric Blank, the PUC chair, estimated that beneficial electrification could grow demand for electricity by 30%.
The takeaway here is that you can expect more wariness as we move forward about avoiding missteps. Nobody I know argues that shutting down coal plants is a mistake. They’re horribly polluting and the power has become expensive. But neither is the precise path forward altogether clear.
Photo: Transmission lines near Longmont in September 2020/Allen Best