Hydropower project tested on Merrimack

An Amesbury section of the Merrimack River is the site of a project aimed at demonstrating a new technology to harness energy from water currents.

A Virginia-based firm is conducting the three-month project from a barge next to the Chain Bridge in Amesbury.

The firm, Verdant Power, is developing technology for a new type of hydropower that, unlike conventional hydropower, does not involve the use of dams. Instead, it seeks to capture ''kinetic energy" from the moving water found in tidal streams, rivers, and the ocean, and in human-made facilities such as aqueducts and irrigation canals.

''We find a core stream of a river or tidal strait and then we position underwater turbines in that core current. Then we convert that kinetic energy to mechanical power, which is then converted to electrical power," said Trey Taylor, president of Verdant Power.

The Amesbury project will involve testing six turbines of a type designed by Alexander Gorlov, a retired professor at Northeastern University. Verdant Power is teaming with Gorlov's company, GCK Technology, on the effort.

The project is being funded with the help of a $500,000 grant awarded last fall from the Massachusetts Renewable Energy Trust Fund, which supports projects that promote the use of alternative energy technologies.

Early this month, Verdant staff lowered the first of the six Gorlov Helical Turbines into the water from a barge next to the bridge. A second one was added several days later.

Since then, the company has been measuring the revolution speed of the turbines, which are affixed to the barge and about 8 feet below the water surface. It also has been seeking to determine which generator to ''marry up with the turbines," among other calculations, Taylor said.

The turbines, whose blades resemble eggbeaters or hand-pushed lawn mowers, turn shafts that then power the generators.

He said Verdant planned to lower the remaining four turbines into the water in the coming weeks, one of them as early as this past week.

Taylor said the project, which received approvals from state and federal agencies, including the Army Corps of Engineers and Coast Guard, is scheduled to conclude in late October.

Verdant is testing a different turbine in a larger ongoing project on the East River in New York.

Taylor said the company believes the technology it is developing can help rejuvenate hydropower, noting that it poses none of the negative impacts on fish populations or the visual environment that a dam can bring. Plus, like conventional hydropower, it would not require any burning of fossil fuels or emit pollutants into the air.

He also noted that the system the company is developing can work with different types of turbines in different water conditions. And he said that, in addition to generating electricity, the technology can be used for other mechanical purposes, including pumping water for irrigation or through systems that remove impurities and salt.

Amesbury Mayor David T. Hildt is enthusiastic about the project.

''I am a believer in the possibilities of renewable energy sources," he said. ''And I think that in this day and age, especially when you hear about gas prices continuing to increase and key oil lines that are under the threat of terrorist attack, when you have some passive turbines that are being moved by the forces of nature and are capable of producing a significant amount of electrical energy, it's certainly an attractive concept."

He said he was hopeful that Verdant could offer a presentation on its project to Amesbury schoolchildren, something Taylor said he is interested in doing.

The Massachusetts Renewable Energy Trust, which awarded the $500,000 grant, is administered by the Massachusetts Technology Collaborative, a quasi-public agency. The grant was one of four made from the trust under a program to support emerging energy technology projects.

''This is an exciting project for us," said Chris Kealey, spokesman for the collaborative. He said it helped further the mission of the trust to ''increase the supply of and demand for renewable energy across the state and to maximize the environmental benefits that come from renewable energy," which is energy that comes naturally and continually from the environment.

Taylor said Verdant chose Massachusetts for a demonstration project because of the availability of the state funds. He said it picked the Merrimack River site because it is accessible and because there were marinas in the area where it could do its outfitting, and a local barge company.

Taylor said the six turbines together are expected to generate about 20 kilowatts of power, or enough to supply the needs of about 18 homes. He said it is estimated that a larger facility on the river could generate 500 kilowatts, or enough to power about 450 homes.

''That would displace the equivalent of over 1,000 tons of coal . . . or 3,400 barrels of oil, or 21.5 million cubic feet of natural gas, in a year," he said.

Taylor said that his company hopes eventually to be a commercial supplier of power. Depending on the outcome of the demonstration project, he said it might consider the Merrimack River as a potential energy-producing site.

He said one factor in weighing that possibility is whether there is any evidence of the turbines harming snub-nosed and Atlantic sturgeon, two federally endangered fish species that inhabit the river bottom. He said the turbines sit well above the river bottom, and are designed not to hurt the fish. But he said in view of their endangered status, the company would want to be sure there is no threat to the fish before proceeding with any commercial power generation.

Another factor is whether there is a sufficiently reliable current speed to make it economically feasible to tap the water.

Even if it does not end up seeking to produce energy from the river, Taylor said the project will prove valuable.

''The research we're doing here on how the system operates could be applied in a lot of places in the state of Massachusetts and elsewhere," he said.