The U.S. Army Corps of Engineers this week kicked off a new three-year study of a Maine dream of the past half century - harnessing the giant tides of Passamaquoddy Bay for a mammoth tidal power project.

The original idea was proposed by Dexter Cooper in the 1920s and a decade later won the support of President Franklin D. Roosevelt.

Construction of the tidal power project at Eastport, the most easterly city in the United States, began in the 1930s only to be abandoned when it became obvious that costs would exceed the value then of electricity that could be produced.

The original Passamaquoddy tidal power project was to have been a joint U.S.-Canadian venture. The new project which the Corps of Engineers will study would be smaller in scope and be wholly within the United States. Canadians are about to undertake a similar study of a $33 million hydroelectric power project in the Bay of Fundy.

Tidal dams would harness the water of Cobscook Bay which has the greatest tidal range in the continental United States.

Col. John P. Chandler, chief of the New England division of the Corps of Engineers, who presided at the public meeting here yesterday, said that while previous studies failed to establish that a tidal facility on the eastern Maine coast would be economically feasible, "we are now taking another look because we need to examine every possible means to reduce New England's dependence on imported fuel for electrical power.

"A tidal power project could become economically attractive if the price of oil rises faster than inflation and no better alternatives are available."

He said Congress authorized the stuky because of the "uncertainties about the availability and price of petroleum."

Acknowledging that the cost of a tidal power project is substantial, Col. Chandler said that after such a facility is completed and operational the annual cost for generating power and for maintenance is far less than any known fuel-dependent alternative.

According to 1976 estimates, total cost for a project made [WORD ILLEGIBLE] five 12.5 megawatt units plus [WORD ILLEGIBLE] megawatt auxiliary generating would be $281.7 million.