Any sober reckonings of our energy future ultimately come down to a very smudgy realization: We may be stuck with coal for a long time.

In fact, Colorado gets 72 percent of its electricity by burning coal. In Utah, it's even higher, 86 percent, and in Wyoming 95 percent. And even if we didn't burn coal, the Chinese and Indians likely would, because they have it and they want our lifestyle.

Wind energy? You bet. The industry has surged in wind-rich Colorado.

Still, wind and solar together provided only 6 percent of Colorado's electrical supply as of 2007, while hydroelectricity delivered another 5 percent.

Natural gas also has promise. Advocates — including Ted Turner, former U.S. senator Tim Wirth, and energy activist Randy Udall — all argue that we need to produce more electricity by burning natural gas, which produces only half the carbon dioxide of coal.

But can natural gas fill the void if we abandon coal?

Not likely, says Vincent Matthews, the Colorado state geologist. He says that's why technology to sequester carbon dioxide from coal-burning power plants must be developed.

To that end, the Colorado Geological Survey is launching a three-year research project near Craig, adjacent to Colorado's largest array of power plants. Geologists intend to drill a well 8,500 deep to learn whether the carbon dioxide can be sealed within the underlying sandstone formation, so it won't escape into the atmosphere.

Geologists also want to understand whether minerals within the sandstone might react to the carbon dioxide in a way that blocks integration of the gas into the microscopic pores. No actual injection of carbon will be done, however.

The project is consistent with the Colorado Climate Action Plan of 2007. That plan calls for sequestration of carbon through such techniques as revised farming practices, but also by injection deep underground. Colorado has previously participated in several experiments, including one in New Mexico, but just 20 miles south of Durango.

President Barack Obama he said he supports continued research into the feasibility of carbon capture and sequestration. The federal stimulus packaged passed by Congress last winter included a major bundle for research. This particular grant of $3.8 million is among $75 million announced this week by the U.S. Department of Energy.

Oil-shale developer Royal Dutch Shell, oil field services operator Schlumberger, and Tri-State Generation & Transmission, part owner of the adjacent plants, collectively chipped in nearly $1 million for the Colorado project. Xcel Energy declined.

Is it safe?

Some aspects of carbon sequestration are well understood. For example, drillers have long used carbon dioxide to dislodge oil from geological formations. In fact, a major source of carbon dioxide exists in southwestern Colorado, near the community of Montezuma. Carbon dioxide from that underground deposit, plus another source near Walsenburg, are piped to oil fields in West Texas.

“People say, ‘Can you do this safely?'” says Matthews, a long-time oil and gas geologist. “Nature has been doing this safely for 100 million years.”

But can carbon sequestration be done on a massive scale as needed to justify continued burning of coal? Anti-coal activists see carbon sequestration as a giant gamble. They paint pictures of carbon dioxide, an aphyxiant, boiling to the surface, as has sometimes happened naturally.

Nancy LaPlaca, a Denver-based activist, points out that injection of 165 million gallons of toxic waste deep underground at the Rocky Mountain Arsenal, just east of Denver, from 1962 to 1967 was accompanied by 1,500 seismic events, three of them more than 5 on the Richter scale. When pumping ended, so did the earthquakes.

“This is folly,” LaPlaca says of carbon sequestration. “It is very risky. The cost is enormous on the scale at which we would have to do this. It is absolutely staggering.”

LaPlaca and others believe the money would better be invested in improving efficient use of existing electricity and increasing renewables supplies.

Vacliv Smil, a professor of energy at the University of Manitoba, has argued that carbon sequestration of the magnitude needed will be difficult. Last year he told the New York Times that capturing and burying just 10 percent of the carbon dioxide emitted during a year from coal-fired plants would require moving volumes of compressed carbon dioxide greater than the total annual world flow of oil.

But Smil has also asserted that it's unrealistic to think that the world can leave behind coal-fired generation any time soon.

Tri-State, which gets about half the electricity from the power plants at Craig, sees continued burning of coal, because it is abundant and cheap — even with a price on carbon emissions.

“We feel we will be using it in the future,” says Jim Van Someren, manager of communications at Tri-State. “We just need to find ways to use it more wisely,” he says.

A part of this calculus, he acknowledges, is the expectation that “at some point we will be operating under a carbon-constrained scenario.”

Coming carbon caps

The first federal constraint could come late this year. The Waxman-Markey bill passed by the U.S. House of Representatives caps carbon emissions. Some climate-change activists charge that the legislation grants utilities too many allowances to effectively drive innovation. Others see it as a tepid step in the right direction.

Opponents see Waxman-Markey as too costly and a step in the wrong direction. After all, if greenhouse warming theory is half-baked, then burning fossil fuels isn't a problem.

Matthews sees a continued role for coal in our future — and he doesn't see natural gas filling the void.

“We're not going to be off coal for a long time,” he says “We can't possibly get off coal for a long time.”

T. Boone Pickens has famously argued that natural gas will be the bridge fuel to an economy built upon the foundation of renewable sources. Lately, as new techniques have inflated estimates of natural reserves in the United States, some in the environmental community have agreed that it will be the bridge fuel.

Matthews isn't persuaded.

“I agree with a lot of what Pickens wants to do,” he says. “But my concern is that everybody wants natural gas to be their answer. Pickens wants it to displace imported oil. Proponents of renewable energy want it as a backup to fill the intermittency of wind and solar. Anti-nuclear people want it instead of nuclear. And anti-coal people want it to displace coal. Everybody wants to put all their eggs in the basket of natural gas.”

But Matthews isn't convinced enough natural gas exists to be the answer for all needs. Unlike the earlier deposits of natural gas, the so-called shale plays stop producing very rapidly, requiring far more drilling. To get the same volume of gas in 2008 as was produced in 1995, he says, required more than three times as many wells, 31,000 and 9,000 respectively.

“You have to drill more and more just to stay even,” says Matthews, for many years a leading geologist for Amoco.

It's not about reserves, he goes on to explain. It's all about production.

“It's just like oil shale. What difference does it make that the U.S. Geological Survey has increased the estimated reserves of oil shale from one trillion to 1.5 trillion barrels. We haven't go gotten one drop from it yet.”

Despite all the fanfare about the so-called shale plays, says Matthews, U.S. production of natural gas last year had not risen from 2001. Nor, he points out, has U.S. production of gas regained 1973 levels. The gap is filled by imports.

Jim Rodgers, the chief executive of Duke Energy, one of the nation's largest utilities, made the same point during a talk last week in Boulder. He called natural gas the “crack cocaine of our industry.” Rodgers, whose company recently announced a major wind farm in Eastern Colorado, said he believes all options need to stay on the table, including nuclear and coal. But sequestering coal remains a daunting challenge, he said.

Challenge and expense

Matthews readily admits to challenges. He doesn't hold up earthquakes as a show-stopper. However, because of the experience at the Rocky Mountain Arsenal near Denver, the issue must be dealt with. “I tell people, when that issue comes up, don't blow it off.”

But carbon sequestration will be expensive. “It will be expensive to capture, expensive to compress for injection, and it will be expensive to inject it.”

By some estimates 30 to 40 percent of the energy harnessed from a coal-fired power plant could be required to capture and store the carbon.

A study by Harvard researchers Mohammed Al-Juaied and Adam Whitmore released in July estimated that carbon capture and storage will add an average 10 cents per kilowatt hour to the price of electricity, or about double the going rate in Colorado.

Other states in the Rocky Mountains have also been planning for carbon sequestration. Wyoming, with its still-large stores of coal in the Power River Basin, has begun to assemble the regulatory and legal framework for governing risk. Two years ago legislators adopted laws governing administration of pore spaces, the spaces between rock in underground formations where the carbon would be injected. As well, universities in Wyoming and Utah have geared up with special divisions devoted to sequestration efforts.