Jan. 4--Coal mine employment levels are down sharply from years past. Recent power plant construction has been heavily skewed toward cleaner-burning natural gas plants.

And a heart-rending mining accident this week in West Virginia has highlighted the risks still involved in simply getting coal out of the ground.

Are these signs that coal is on its way out as a fuel source?

Not a chance.

"We're not moving away from (coal); we're not moving to substantially increase its use," said Mark Morey, director of North American power for Cambridge Energy Research Associates in Washington, D.C.

Coal makes up just more than half of the fuel used by U.S. power plants operated by investor-owned utilities. While that is a minor decrease from about a decade ago because of the flurry of gas-fired plants that have been built, the U.S. Department of Energy predicts coal's share of U.S. power generation will climb to 57 percent in 2030.

Tampa Electric's coal plants generate nearly 54 percent of the utility's electricity. Progress Energy Florida of St. Petersburg, which operates a nuclear plant in Crystal River, is less reliant on coal, which accounts for about 32 percent of its generation needs.

Simple economics help explain coal's enduring appeal. In most areas, coal and nuclear power are the most economically attractive options for "base-load" plants, which operate round-the-clock to generate the backbone of a utility's electricity output.

The construction of gas-fired generating units surged in recent years, mostly for plants designed to operate during periods of peak electricity demand, intermediate plants such as Tampa Electric's Bayside Power Station in Tampa, and for some high-efficiency base- load plants that also use steam power to generate electricity.

But the recent jump in natural gas prices has prompted an increase in the number of proposed coal-burning plants. Meanwhile, growing global energy demand has pushed coal prices higher, albeit not as sharply as natural gas, leading to big profits for many companies with significant mining operations.

Two Tampa Bay area companies have benefited from the strong coal market. TECO Energy, parent of Tampa Electric, has enjoyed a strong boost in earnings from its TECO Coal subsidiary, which operates coal mines in Kentucky.

Until a few years ago, Walter Industries of Tampa had planned to jettison its natural resources business, which included its coal- mining and natural-gas operations, after a September 2001 accident that killed 13 miners in a Walter-owned coal mine in Alabama.

Then prices for coal and natural gas began to jump, prompting the company not only to stay in the mining business, but to seek opportunities to expand it. In October, Walter acquired a controlling stake in a new Alabama mine that is expected to begin operations during the first half of this year.

About three-quarters of Walter's coal production is focused on metallurgical coal, the type of coal used in the production of steel.

"It's a business we're very excited about," Walter spokesman Mike Monahan said Tuesday.

As coal plants age, utilities will have to replace them with new plants. Many will be replaced, again, by coal plants, although a revival of interest in nuclear power could affect the number of coal plants that are built, according to Cambridge Energy's Morey.

"We're moving to sustain its (coal's) contribution," Morey said, "and that still takes some work."