Water Power
New energy at an old dam
Since one nuclear power plant can take a decade and more than $3 billion to build, and scares nearly everyone living within 50 miles, it may be better to build dozens of quietly humming, nonpolluting small dams to generate electricity. They could nestle right into some long-abandoned textile-or lumbermill dam, and draw their power from the flowing river water. That is a proposal now being tested in several New England states.
Like the wood stove and the windmill, hydroelectric power is making a comeback. This week the largest such plant to open in New England in more than half a century will be dedicated in Lawrence, Mass. Project promoters proudly wear bright red buttons that read ONE DAM SITE BETTER.
The structure sits unobtrusively at one end of the Great Stone Dam, a 900-ft-long, 40-ft.-high granite block structure that spans the broad Merrimack River. When that old dam was built in 1848, it was the engineering marvel of its time and provided mechanical power for the surrounding textile mills of Lawrence. But the dam fell into relative disuse in the 1950s, when the city's thriving textile industry withered as factories moved south.
In 1976 a group of six Massachusetts investors approached the Essex Co., an old-line New England firm that had initially built and continued to own the dam, with a proposal to build a hydroelectric plant there. Company stockholders were receptive because the dam faced financial troubles. The Department of the Interior had ordered the company to construct a $1.5 million fish ladder to help the Merrimack River's growing schools of Atlantic salmon move upstream to spawn. The company stockholders agreed to sell out to the investment group, which later formed a partnership with E G & G, a Wellesley, Mass., energy-equipment company (1980 sales: $613 million). Financing for the $28 million project came from Chase Manhattan Bank, Mutual of New York insurance company and two smaller New England banks.
When fully operational, the plant is expected to generate enough electrical power to meet the needs of 17,000 homes, giving the investors a return of 15% on their money, a profit that few utilities can match. Says Essex Chairman Jacek Makowski: "A hydro project can be viewed as an oil well with unlimited resources. Once you have the capital investment finished, you are good for 50 years, maybe longer."
The ambitious Lawrence dam partners now have several more hydropower sites in New England under development. They are building a $6.3 million project on the Contoocook River near Concord, N.H., and a $2 million one on the Wells River in Vermont. The two dams will serve a total of about 5,000 customers.
The new hydroelectric-power generation in New England is due in part to advances in turbine technology for "low head" dams. The new turbines produce electricity by having water flow horizontally, under modest pressure, against the blades of the turbine. The machines look something like submarines sitting on the bed of the river. Traditional hydroelectric dams like the Hoover Dam on the Arizona-Nevada border must be hundreds of feet tall so that the water can fall from great height and with huge force and speed against the turbines. Although low-head dams are widely used in Europe, relatively few of those in the U.S. generate electricity.
Hydro power is not about to free the U.S., or even New England, from its dependence on either nuclear power or imported oil. Less than 5% of the region's electrical power now comes from hydroelectric sites. The New England River Basins Commission has made an inventory of the 10,000 dam sites in the region's six states and concluded that only 320 of the dams are now economically feasible. If those were developed, water-energy production would rise to only about 7% of daily usage. But even that amount would mean that the U.S. could import 3.5 million fewer barrels of OPEC oil annually. -
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