© Charles BertramAbout 50 state and energy-industry officials toured an area Thursday where an 8,300-foot-deep well is being drilled near Hawesville. The experimental well will be used to store carbon dioxide.
Beside a cow pasture in Hancock County, scientists are drilling through 8,000 feet of rock, hoping to learn how to lock away forever an invisible gas that threatens Earth's climate and our way of life.

Science fiction? No, but it's a science experiment that, if it works, would be carried out on a scale never before seen.

The idea is to capture the carbon dioxide, or CO², that spews into the air when coal is burned to produce electricity. The gas, which also occurs naturally, is one of the causes of global warming.

Drilling began April 24, and the work has continued around the clock. By Thursday, when the media and officials involved in the project were invited for a first look, the drill had sunk to 3,660 feet.

In a month and a half, it will stop at 8,350 feet, in so-called "basement rock" that is more than 1 billion years old. That will make it one of the deepest wells ever drilled in Kentucky.

The $8.1 million Kentucky Geological Survey project is being paid for by $1.5 million from Kentucky taxpayers, with the rest coming from Illinois, the Tennessee Valley Authority and several companies, including E.ON U.S., the company that owns Kentucky Utilities.

The Hancock County well in Western Kentucky is one of a number of test wells in various stages around the country being coordinated by the federal Department of Energy. It was one of a $5 million package of carbon-dioxide-related projects ordered by the General Assembly in 2007 when it approved House Bill 1.

Because coal produces more than half the nation's electricity, and 90 percent of the power in Kentucky, the legislature was trying to get ahead of what everyone agrees will be laws that limit carbon dioxide emissions.

"I know of no issue - no issue - that is any more important that this energy issue and how we will handle it," said House Majority Leader Rocky Adkins, D-Sandy Hook, who was introduced Thursday as "the author and pusher" of HB 1.

Some of the state money, along with money from utilities, is going to the University of Kentucky's Center for Applied Energy Research, where researchers are trying to find more efficient ways to strip the CO² from flue gases leaving power plants. At this point, center director Rodney Andrews said Thursday, the process is such an energy hog that a third more coal would have to be mined and burned just to capture the carbon dioxide.

If geologists find the kinds of rock they expect under Hancock County, CO² compressed so much that it has turned into a liquid will be sent down to porous layers somewhere between 3,780 and 7,780 feet.

There it will be forced into spaces in a type of limestone called Knox dolomite, which is found beneath much of Kentucky and the region.

"Imagine a jar of marbles," said Brandon Nuttall, a geologist with the geological survey. "The spaces between the marbles - that's where the CO² will go."

And that's where, if the scientists are right, it will stay.

Rick Bowersox, another KGS geologist who is co-manager of the project with Dave Williams, said that part of the science is proven.

If the right kind of impervious rock is found above the porous layers, and the well is sealed, he said, the CO² will have no place to go.

CO² has been injected into oil wells beneath the North Sea for decades, he said. They aren't doing it there to get rid of the CO², but to push more oil out of the rock so it can be pumped to the surface.

Bowersox said he sees a certain balance in the closed loop of getting rid of CO² by putting it down a well.

"We mine coal out of the ground to burn it, that produces carbon dioxide, and we capture that and put it back in the ground," he said.

Bowersox said carbon storage is a good way to allow coal to be burned while other sources of energy are being developed. And, he said, someone might someday find a way to put huge amounts of CO² to some beneficial use, and pull it back out of the ground.

HB 1 calls for another experimental well that is just getting started in Hopkins County. The CO² pushed down that well will be used to push oil out.

An Eastern Kentucky well also is in the planning stages. That one has been delayed by a lack of partners to share the cost, but Adkins said Thursday that an announcement could come soon.

The Hancock County will use 3,000 tons - a tiny amount compared with the many millions of tons produced by power plants each year. The CO² will be commercial grade - the kind used to carbonate soft drinks or make dry ice for refrigeration.

Two nearby domestic water wells and several springs will be monitored for years to make sure none of the CO² is getting to places it shouldn't be.

State energy secretary Len Peters said Thursday that figuring out how to capture CO² and lock it in the ground is of vital importance to Kentucky's long-term energy plans.

The state is putting more emphasis on alternative fuels, he said, but that won't be enough.

"We can't get from where we are today to where we need to be in 2025 without coal being part of the solution," he said.