Glenwood Springs-based electric cooperative says it can leap from 50 percent emission-free energy to 92 percent by next year—despite owning a coal plant. Exactly how does this work?
Let’s start with the obvious. The sun doesn’t always shine and, except for springtime in Colorado, the wind doesn’t always blow.
So how can Holy Cross Energy, which serves the Vail, Aspen, and Rifle areas, achieve 92 percent emission-free energy in 2024? Last year it was 50 percent.
And if Holy Cross can do it, what is possible for utilities serving Crested Butte and Steamboat Springs, Holyoke and Crestone, Sterling, and Pueblo?
By the way, Holy Cross still owns eight percent of Colorado’s newest coal plant, Comanche 3.
Directors of Holy Cross several years ago adopted what seemed like the audacious goal of achieving 100 percent emissions-free power by 2030. Municipal utilities serving Aspen and Glenwood Springs already have 100 percent renewables, but do not own their own generation.
I expected small steps. Wind and solar have become far less expensive than coal or gas. But what about windless, sunless days?
Resource adequacy has become a major question in this energy transition. Coal plants, if sometimes down, are far more reliable than wind and sunshine. Now we’re hurriedly closing those high-priced and polluting plants. Natural gas can respond quickly to demand. However, those plants are costly and pollute, too.
Do we need more natural gas plants?
Colorado’s two largest electrical providers, Xcel Energy, and Tri-State Generation and Transmission, both say they can reduce carbon emissions to 80 percent carbon by 2030 as compared to 2005 levels. But both have refrained from embracing higher, short-term goals.
Tri-State*, which delivers power to 17 of the state’s 22 electrical cooperatives, warns of ambitions outpacing realities. Duane Highley, the chief executive, likens resource adequacy to a “big bad wolf.” The Western Energy Coordinating Council in December warned that Western states risked having insufficient resources by 2025 to meet electric demand on the grid they share.
Storage will be crucial. Lithium-ion batteries, if increasingly more affordable, can store electricity for just a few hours. We need technologies that can store energy for days if not weeks. Xcel Energy will be testing one such long-term technology, called iron-air, at Pueblo. Colorado wants to be part of the elusive answer to hydrogen, perhaps using existing electricity infrastructure at Brush or Craig. And transmission and other new infrastructure, such that could allow Colorado to exploit the winds of Kansas or the sunshine of Arizona, can help—but remains unbuilt.
Holy Cross actually has the second lowest electrical rates among Colorado’s 22 electrical cooperatives. And its rates are five percent less than those of Xcel. This is not Gucci electricity, a Tesla Model X Plaid. The Aspen Skiing Co. and Vail Resorts make snow with some of Colorado’s lowest electricity rates.
Bryan Hannegan, the chief executive and head wizard at Holy Cross, laid out his utility’s broad strategy in recent presentations to both state legislators and the Avon Town Council. Holy Cross, he explained, will add new wind from eastern Colorado and several new solar-plus-storage projects within its service territory.
The cooperative also intends to integrate new storage in homes and businesses. It incentivizes home batteries that can be tapped as needed to meet demand from neighborhoods. Holy Cross also wants to integrate vehicle batteries, such as from electric school buses, in its efforts to match demands with supplies. Time-of-use rates will be crucial. This market mechanism aims to shift demands to when renewable electricity is most readily available — and cheapest.
Importantly, Holy Cross expects to achieve this high mark without need of new natural gas capacity. Many environmentalists loathe the idea of new and rarely used – but always expensive – natural gas plants. Most utilities see even more gas generation as necessary.
Speaking to the Avon council, Hannegan expressed confidence Holy Cross can meet growing demand from electric vehicles, heat pumps, and other uses. He called it “smart electrification.”
Holy Cross’s journey from 92 percent to 100 percent, though, will “be a bit of a doozy,” he said. He likened it to the climb from Camp 4 on Everest to the peak.
“We have to think about how we balance (supply and demand) at every location on our grid at every moment of every day,” he said. That “fine-grained balancing” will be “quite an engineering challenge. There is reason we have given ourselves six years” to figure this out.
What about that coal plant that Holy Cross still owns (but consigns the output to wholesale provider Guzman Energy)? Does that muck up the math? Can Holy Cross truly claim 92 percent ? And what prevents other utilities from following in its footsteps? These are questions I will ask Holy Cross and others in coming weeks.
by Allen Best
This column is based on reporting that can be found at BigPivots.com, which offers deeper dives into Colorado’s energy, water, and other transitions.
*Tri-State delivers energy for 17 electric cooperatives, including Sangre de Cristo Electric Association.