Capturing methane gas vented from coal mines could go a long way toward establishing a large volume of affordable carbon credits, according to regulatory and industry officials.

So far, there seems to be support in Congress to forego a cap on methane emissions from mines and instead provide incentives to capture coal mine methane to either "destroy" it or use it for on-site electrical generation.

Officials say the volume of carbon credits that could be generated from coal mine methane utilization programs would go a long way toward making sure a carbon cap-and-trade regulatory system succeeds.

"I think there is enough momentum in Congress understanding the real value that offsets have in cap and trade. Coal mines in particular can provide value early on," said Marisa Buchanan of Verdeo Group, which develops carbon capture programs.

Buchanan spoke at the U.S. Coal Mine Methane Conference in Boulder, Colo., last week as part of the Environmental Protection Agency's Coalbed Methane Outreach Program.

Underground mines commonly vent methane as a safety requirement.

Surface mines vent methane, too, but have fewer opportunities to capture methane in ways that would qualify for carbon credits.

Methane is also a potent greenhouse gas, with 23 times the heat-trapping capacity as carbon dioxide. U.S. mines vented some 158 billion cubic feet of methane gas in 2006, according to industry officials. In terms of volume, that's equal to all the natural gas produced in Wyoming for a month.

Industry and regulatory officials at the conference touted the importance of capturing coal mine methane because it provides a great opportunity to quickly generate a significant volume of carbon credits.

For example, one carbon credit program based on coal-mine methane might provide 10 times the credits as one agriculture or forestry program.

"If you remove coal mines from that opportunity, you're just looking at agriculture and forestry opportunities, and those are not available in the early years and only when the price of carbon hits a really high number, like $45 (per metric ton)," Buchanan said.

If a company has a facility that exceeds its greenhouse gas emissions cap, it must hold enough carbon credits -- or offsets -- to make up for the surplus emissions. The U.S. House passed an energy bill earlier this summer with provisions to give away for free some credits to certain emitters, including coal-fired power generators.

But the coal-fired utility industry worries it will still have to buy more credits on the open credit market without knowing what those prices will be. That uncertainty fuels a lot of opposition to cap-and-trade legislation currently before Congress, according to officials.

That's why it's important to encourage low-hanging fruit "offsets" such as coal mine methane capture, already a quickly growing technology all over the world and especially in China.

Robert Bassett of the Holland & Hart law firm said venting coal mine methane is first and foremost a safety issue for coal miners.

"You should do something with the methane," Bassett advised industry representatives. "You should flare it. If you can capture and use it on site, more power to you."

Contact energy reporter Dustin Bleizeffer at 307-577-6069 or dustin.bleizeffer@trib.com. Read his energy blog at tribtown.trib.com/post/DustinBleizeffer/blog