Colorado’s electric power sector can cut greenhouse gas emissions by 98.5% by 2040 without major policy changes or major new costs to consumers, according to an optimistic state analysis that came as a happy shock to energy officials and environmentalists.
Current Colorado law targets an 80% carbon reduction from the highly polluting power plant sector by 2030, but did not try to pinpoint a year when net-zero emissions from electricity generation were possible, said Will Toor, executive director of the Colorado Energy Office. State officials welcome the analysts’ view that near-100% cuts from a 2005 benchmark are within reach, Toor said.
“The really big surprise in this study was just how far we are able to reduce emissions, at no incremental cost” from currently approved plans, Toor said. The modeling and analysis were done by a clean energy transition consultant.
The economically friendly scenario would cut Colorado’s electricity-related carbon emissions to 565,000 tons in 2040, from the 2005 benchmark of 40 million tons.
Western Resource Advocates, a prominent energy and environmental nonprofit, called the results “promising” and said they provide “valuable insights.”
“This is an exciting result because it shows the emissions reduction progress that is possible as the lowest-cost option,” said Gwen Farnsworth, deputy director of state advocacy at WRA.
The lowest-cost option in the independent analysis also avoids relying on controversial technologies such as carbon capture and underground storage, or unproven hydrogen fuel systems, to get to the 98.5% cuts. Achieving true 100% cuts and net-zero electricity generation by 2040 would likely require more of those expensive innovations, including relying on the growing call for exploiting geothermal energy in Colorado, the analysis said.

One scenario in the analysis, which tested multiple combinations of policy and technology, put the cost of getting to 100% at about $9 billion in additional power spending, or as much as 25% more than current costs, Toor said.
“I’m not sure that you would want to spend a really large sum to pick up that last little bit of emissions,” Toor said.
Battery storage technology, hydrogen research and other potential breakthroughs are advancing so quickly, officials said, that any number of combinations could get to net-zero in the next 17 years without trying to account for them with new policy changes for energy companies or regulators.
Some environmentalists who have seen early copies of the state analysis, which will be finalized in December, reacted that if it’s this easy to get close to carbon-free electricity by 2040, why not shoot for sooner?
“If we can do it by 2040, then let’s be more ambitious and see if we can do it even faster, right? What can we do to be even more innovative?” said Ean Tafoya, Colorado director of GreenLatinos.
Colorado legislation set targets for reductions of carbon emissions in the overall economy, in order to combat worldwide climate change caused by greenhouse gas buildup. Those targets were 26% by 2025, 50% by 2030 and were recently expanded to 90% cuts below 2005 levels by 2045. There’s a net-zero target for the economy overall by 2050.
A separate law requires the 80% cuts to greenhouse gas emissions from the power generation sector by 2030, and power companies like Xcel are required to file plans with the state showing how they will get there. Xcel and others have said they are on track to reach those goals, with scheduled closures of high-emitting coal power plants like Pueblo’s Comanche complex, timed to be complete by the end of 2030. Comanche is the single largest carbon-emitting site in Colorado.
Power generation has been one of the largest components of greenhouse gas emissions, along with vehicles powered by fossil fuel, heavy industry like cement and steel production, and building heating primarily achieved through natural gas.
The low-cost scenario in the analysis, conducted by Ascend Analytics, assumes that clean technology boosters such as state policy and the U.S. Inflation Reduction Act and its energy investment credits will continue on through 2040. Power companies and co-ops are replacing coal and natural gas-fired plants with wind, solar and massive battery arrays that can store cleanly generated power for anywhere from four to 100 hours when renewable sources are limited.
Colorado is uniquely positioned among many states by having the optimal climate and geography for both solar and wind power replacement of fossil fuels, Toor said. A 98.5% achievement in carbon cuts would put Colorado among national leaders in clean energy, he added.
“We’re analyzing the study, and we’re encouraged by the Colorado Energy Office’s findings. The state’s policies will enable us to reduce carbon emissions greater than 80% by 2030 and will inform our future investments into the local infrastructure necessary to move clean energy reliably into our customers’ homes – while keeping bills low,” an Xcel Energy spokesperson said.

State leaders, companies, research labs and nonprofits will continue to explore alternatives such as hydrogen, geothermal energy and so-called advanced nuclear reactors, but the new study shows Colorado doesn’t need to rely on their success, Toor said. That doesn’t mean they won’t hold their own positive surprises.
“If you think, for instance, about wind and solar, the cost came down far more rapidly than anybody was projecting 20 years ago,” Toor said.
The low-cost, steady-as-it-goes scenario projects the state tripling its wind generation from current levels, and increasing solar generation by nearly fivefold, Toor said. Under that favored scenario, wind and solar generated in-state would be about 76% of electrical capacity, with most of the rest imported by clean wind sources outside Colorado. About 1% would be generated by natural gas, which in 2040 would be a backup and fill-in source.
The economically friendly scenario not only drastically reduces carbon emissions, but also nearly eliminates other troublesome Colorado pollutants such as sulfur dioxide and nitrogen oxides, a prime component in the state’s ongoing violations of EPA ground-level ozone caps.
Many environmental justice groups are celebrating the fact that Colorado was not named as part of a new set of regional hydrogen innovation hubs in Department of Energy awards, Tafoya said. Colorado is already struggling to meet environmental justice requirements with the policies it already has in place, which call for reducing pollution in highly impacted neighborhoods.
The state must also be fair in how it evaluates possible new carbon pipelines and other clean energy infrastructure, environmental groups have said.
The new analysis should encourage even more innovation in clean energy, Tafoya said.
“Wouldn’t it be amazing if Colorado was a global leader who didn’t just wait until 2040,” Tafoya said. “But if we use this as reassurance that we can be even more bold for energy, justice and equity.”