Call it pot power.

Marijuana seized by federal authorities will help fuel a power plant near Ft. Lauderdale later this year in the first known effort to convert contraband into kilowatts.

The alternative energy source will not save enough barrels of oil to make a dent in Florida Power and Light Co. customers' electric bills, but it will help the federal government solve an increasingly difficult problem -- how to dispose of millions of pounds of smuggled marijuana seized every year in Florida.

A decade ago, U.S. customs agents simply hauled the approximately 1,000 pounds of illegal marijuana they confiscated annually to a small airport outside Miami. They burned the drugs openly, under guard, and threw in a few smelly rubber tires to discourage people from enjoying themselves downwind.

But by 1979, U.S. customs agents and Drug Enforcement Administration officials in Florida, the nation's biggest marijuana smuggling zone, were seizing 2 million pounds of marijuana a year.

For awhile, federal authorities tried to throw the grass in with the garbage in conventional incinerators in the Miami area. But the intense heat of the slow-burning drug melted and warped the incinerating machinery.

Then the government began the costly process of transporting the marijuana by armed convoy to a more suitable incinerator four hours north in Orlando. When the incineration fees jumped from $2 to $200 a ton this year, the government sought a more economical alternative.

Florida Power and Light Co. officials agreed to burn the marijuna free of charge at the Port Everglades plant as long as the government pays any necessary expenses, including a new $70,000 shredder-blower specially designed to pulverize the marijuana and reduce the residue.

"Almost anything can be used as a fuel source as long as it burns," said Louis Muniz, a spokesman for the utility. "The problem with marijuana is the effluence -- the smoke. After it is shredded, mixed with oil and burned, there will be so little left that what comes out of the very tall stacks (300 feet high) won't affect anybody. You won't have people running around below saying 'Heeyyy . . . '"

The power plant, which regularly burns oil, will receive marijuana only sporadically, so the drug will not have a great impact on energy production, he said. But one ton of marijuana equals about 2.7 barrels of oil, so the company will save about 2,700 barrels a year at current seizure rates.

In fiscal 1980, which ended in September, the amount of marijuana confiscated in Florida was slightly under the 2 million pounds seized in 1979, apparently because of Coast Guard efforts to keep Cuban refugees from landing at Key West, officials said.