“The time is at hand for America to fulfill man’s centuries-old dream of harnessing the energy of the tides.” That was Secretary of the Interior Stuart Udall writing to President Kennedy in 1963 touting the benefits – cheap energy, jobs, a tourist “magnet” bringing money to the area – of a tidal power project on Passamaquoddy Bay.

Many of the same promises are being made today with proposals to build such facilities at the former Cutler naval base and on the Penobscot River recently announced. A study praising Maine’s potential to produce tidal power was also released this week. While alternative energy production should be encouraged, technical and economic problems still need to be overcome before tidal power is a significant source of electricity.

President Franklin D. Roosevelt pledged $7 million toward the Passamaquoddy Tidal Power Project. More than $5 million was spent in the summer and fall of 1935 and 5,000 people were hired to construct dams and worker housing. The Quoddy project was abandoned in 1936 when Congress failed to appropriate more money for it.

The proposal was revived in the 1960s as part of a plan to dam the St. John River and couple it with tidal power dams in Passamaquoddy Bay. Again, Congress did not appropriate funds for the project and the Dickey-Lincoln dam was finally scrapped due to environmental concerns.

Seventy years later, the Electric Power Research Institute concluded that Maine has “a world class tidal resource” in the Western Passage in Passamaquoddy Bay because of the large tides in the area.

In a report released this week, the institute encourages more pilot projects like ones underway in Scotland and soon to start in New York. This is fine if such research, which should also include universities, is used to move this technology forward more quickly than in the past. The state has already taken major steps to encourage alternative energy production, another recommendation.

Earlier in the month, an employee of the naval facility at Cutler has applied to Federal Energy Regulatory Commission for a permit to conduct a study of Little Machias Bay for a possible tidal power development. He has also proposed an LNG terminal there. Another company has applied for a permit to research the potential for tidal power generation from the Penobscot River around Bucksport.

Although tidal power is a largely untapped source of energy, an international expert, Professor Ian Bryden of Robert Gordon University in Scotland, warns that power capacity from tidal and wave energy projects is often overstated. He cautions that the variable nature of tides must be taken into account when analyzing such projects.

As Maine, the United States and other countries search for renewable energy sources, tidal power may be part of the mix, but history suggests economic, political and technical hurdles will be difficult to clear.