AUGUSTA, Maine — If electricity generated by offshore wind turbines is going to be competitive with electricity generated by other means, the projected price is going to have to be cut roughly in half over the next 20 years, according to an economics professor.
Speaking Tuesday at a wind energy conference held at the Augusta Civic Center, Gary Hunt of the University of Maine said that the projected retail cost of electricity generated by offshore wind projects in Massachusetts and Rhode Island is expected to be close to 20 cents per kilowatt hour.
That price is more than twice the rate now paid by most users in Maine. The current standard price for residential and small commercial electricity users in Maine is between 8 and 9 cents per kilowatt hour, Hunt said.
But the professor said, with adequate investment in the industry over the next decade, a rate of 10 cents per kilowatt hour eventually will be achievable for deep-water, offshore wind farms in the Gulf of Maine.
“If we don’t make the right investment in the 2010s, we won’t realize the benefits in the 2020s,” Hunt said.
Power purchase agreements, which can help power developers bring their projects online, government subsidies and incentives such as tax breaks will be “key” to bringing offshore wind projects to fruition in the next 10 years, he said.
Hunt said the projected rate for the Cape Wind project in Massachusetts is $0.187 per kilowatt hour, while that of the Deepwater Wind project off Block Island, R.I., is $0.244 per kilowatt hour. Both of these projects are expected to involve turbines that will be bolted upright to the ocean floor off the southern New England coast, where the wind resources are not as strong as they are in the Gulf of Maine, he said. Theoretically, there is enough wind in the Gulf of Maine to generate 120 gigawatts of electricity, officials have said. One gigawatt is roughly equivalent to the energy output of one nuclear power plant.
Because there is a high prevalence of wind in the Gulf of Maine, more electricity can be generated relative to the amount of infrastructure required than in other places where the wind doesn’t blow as much, according to Hunt.
Some critics of the concept of developing offshore wind farms in the Gulf of Maine have said that the cost of developing deep-water, offshore wind farms are too high. To recoup the developers’ expenses, the resulting electricity would cost too much for it to be competitive with power generated by other means, they have said.
Hunt, however, predicted that the use of floating turbines instead of turbines that are bolted upright to the ocean floor will be cheaper in the long run.
Specialized “jack-up” barges are needed to erect and install the types of turbines that will be used in Massachusetts and Rhode Island, he said, and typically these barges are very expensive to operate.
“There aren’t that many in the world,” he said.
Floating turbines, however, can be assembled onshore in dry docks or at construction piers, he said, and then towed out to sea by a more traditional type of vessel. Once the turbines are at the wind farm site, they would just have to be moored in place and then hooked up to the cable that feeds electricity back to shore. Where such a cable would come ashore is unclear, he said.
“I think that is quite significant,” Hunt said of the potential for onshore floating turbine construction.
Hunt said his cost estimates include the expense of running a cable to shore and a half-cent per kilowatt hour for adding needed capacity to the grid. There will be regulatory allowances for raising kilowatt hour prices, but those will be capped, he said, which is expected to keep offshore wind power prices competitive in the market.
At the two-day conference, which organizers said drew nearly 300 people, state and wind industry officials said that with development of deep-water wind turbine technology, Maine would benefit from the creation of turbine manufacturing and maintenance jobs. Even turbines mounted on weighted floats that would extend hundreds of feet underwater possibly could be assembled in the deep channel off the eastern shore of Islesboro in Penobscot Bay, industry officials said.