Shaving carbon from power supply for four Colorado cities ‘very doable’
by Allen Best
Platte River Power Authority was the first utility in Colorado to invest in wind energy. That was in 1998 with the purchase of 6 megawatts of wind generation for consumption by Estes Park, the gateway community to Rocky Mountain National Park, and three other cities at the foot of the Rocky Mountains.
If that was a measly amount compared to today’s massive investments in renewables, Platte River is now looking to push the boundaries again. This time it is studying how it might remove its still-heavy smudge of carbon altogether by 2030 and at what cost.
The answer, delivered by consultants at a meeting in Fort Collins this past week, is that carbon neutrality can be achieved but with a price of up 20 percent more for electrical production.
“It seems like it’s doable at first blush, but there are a lot of things to consider going forward,” said Jason E. Frisbie, the chief executive, at the end of a meeting Thursday afternoon in Fort Collins. In addition to Estes Park, Fort Collins, Loveland and Longmont together own Platte River, a wholesale electrical generator.
Attainment of the goal would still include emissions of greenhouse gases. Coal plants would be closed down, their production offset by large amounts of wind generation but also solar.
Existing natural gas plants, however, would continue operation and be augmented by new generation from natural gas combined-cycle plants. This would leave Platte River with about 25 percent of electricity coming from natural gas.
Under the criteria of “zero-net carbon,” as this carbon neutrality is defined, the emissions from natural gas can be offset by sale of renewables to other utilities.
The mere fact that Platte River is even studying the path toward zero-net carbon is notable.
The study commissioned by Platte River reflects the rapidly changing economics and technology of energy. Even if stripped of handsome federal tax credits, renewables have become competitive.
Lazard’s levelized cost of energy study released on Nov. 2 found that on-shore wind energy costs between $32 to $62 per megawatt, compared to $48 to $78 for gas combined cycle and $60 to $143 for coal.
Also notable is the lack of obvious opposition. During a two-hour meeting, including a lengthy question-and-answer session, there were no challenges to the need to reduce carbon emissions. Instead, the hardest questions may have been whether burning natural gas amounts to a net improvement in greenhouse gas reductions. If polls suggest that climate change action remains a low priority for Coloradans, there is relatively little dispute about the idea of human complicity in warming the planet, primarily the result of combustion of fossil fuels.
Two-thirds of electricity delivered by Platte River is produced by burning coal or natural gas, while a third comes from non-carbon sources, especially from hydropower produced on federal dams. Wind is responsible for 11 percent and solar 2 percent.
The zero-net carbon pathway assumes that Platte River would divest itself of its coal generating capacity. The utility outright owns one coal-fired power plant, the 280-megawatt Rawhide plant north of Fort Collins, and has a a stake in two units at Craig for another 154 megawatts of generating capacity.
Platte River describes Rawhide, Colorado’s second youngest coal plant, as being one of the highest-performing coal units in the United States. Debt is not scheduled to be retired on the plant until 2036. Current plans call for continued operations until 2047.
The pathway identified by Pace Global, an energy consulting subsidiary of Siemens, envisions this 434 megawatts of lost coal capacity being replaced by 600 megawatts of new solar capacity and 350 megawatts of wind.
The existing 388 megawatts of generating capacity at natural gas plants would be supplemented by another 286 megawatts of natural gas combined-cycle generating capacity.
It is assumed that more generating capacity from renewables will be required because of the intermittency of both wind and solar.
Wind and solar prices have been tumbling rapidly in the last decade, but the study assumes costs of solar will get even better relative to wind in the next 12 yeas. An advantage to solar is that it can be produced within or near the four cities supplied by Platte River, whereas wind will require transmission. “By 2030, the all-in cost for solar is slightly lower than wind,” says the Pace Global report.
However, wind has a higher average capacity favor, 40 percent compared to solar’s 20 percent. In other words, the intermittency of wind is less than that of solar. That provides added value.
By 2030, wind would constitute the largest portion of the generating mix, followed by natural gas combined-cycle generation, followed by solar and hydro.
Pace Global found some value in lithium-ion battery storage, but with costs too high at this time to be a factor in meeting the carbon-neutrality goal. That may change. “As storage technology matures and there is wider adoption, battery storages can also be considered a part of the portfolio mix for ancillary services needs,” the study notes.
Simple-cycle turbines have advantages, including less cost to build, but are less efficient at converting the gas into electricity than the combined-cycle turbines.
Under the protocol defined by the Carbon Neutral Cities Alliance—which is made up of 20 cities around the world, including Boulder, Colo.—this standard can be met if the carbon-based energy is offset by sale of renewables to other utilities, replacing their carbon energy.
This assumes that other utilities are not all similarly trying to achieve carbon neutrality. Colorado’s largest electrical supplier, Xcel Energy, which is responsible for over more than 60 percent of electrical delivery, plans to switch from coal to wind, solar, and natural gas by 2025, resulting in 55 percent of its electricity coming from non-carbon sources.
Costs could be reduced if Platte River and other utilities in Colorado and across the region join in a regional transmission authority, also called an RTO. Those discussions are underway.
During the question and answer session, most lauded Platte River’s initiative. So did the speaker representing Praxair, the supplier of industrial gases, which has an office in Loveland. The speaker, who said he was from California, went on to suggest caution, as the experience of California, a national leader in renewables, with 53 to 54 percent of its power supply now coming from non-carbon sources, has brushed up against unreliable power.
He also noted he pays 20 cents a kilowatt-hour to Pacific Gas & Electric. In contrast, ratepayers in Loveland pay roughly 6 to 8 cents a kilowatt-hour.
Others during the lengthy question-and-answer session challenged the continued and then expanded burning of natural gas. For example, had the methane that leaks into the atmosphere during drilling and transmission of natural gas been calculated in the greenhouse gas emissions?
The Environmental Defense Fund says that in the first two decades after its release into the atmosphere, methane is 84 times more powerful in trapping heat than carbon dioxide.
Gary Vicinus, the managing director for Pace Global, the consultant responded to that question, as he did to many. “This is a first step,” he said..
Platte River may soon get a head start on its carbon-reduction ambitions. It has received proposals for 150 megawatts of new wind-generating capacity. Platte River’s directors support the proposals, reported Frisbie, the chief executive. He has the authority to enter into power-purchase agreements, but there is no formal date for a decision.
“If we move forward with 150 megawatts of new wind, we will have a generating portfolio that is nearly 48 percent carbon-free,” he said.
All this points to rapidly changing markets and economics, a point noted by Karin Hollohan, the chief administrative officer for Platte River as the meeting in Fort Collins wrapped up.
“Technology is moving very quickly. Prices are moving very fast,” she said.
In the past, electrical providers considered long-range planning to be 10 to 15 years. Now, it’s 5 to 10 years, and those plans may need revision after a couple years.
“We don’t have the answers,” Hollohan added, “but we will continue to study, continue to analyze, and continue to move forward.”
Also on Mountain Town News see: As coal plants close, more calls for 100 percent renewables, a story in the wake of announcement by Xcel Energy of its plans to close two aging coal plants at Pueblo, Colo.
For a look at what one electrical co-operative is doing, see: Is Kit Carson’s renewable goal also the answer to rural America’s woes?