World’s First MW Wind Turbine Is Built

On October 19, 1941, the world’s first megawatt-size wind turbine delivers power to an electric utility grid, on Grandpa’s Knob, Castleton, Vermont. Do to mechanical failures, the prototype turbine was dismantled in 1946, leaving only concrete footings and a marker plaque at the site today.

“The great wind-turbine on a Vermont mountain proved that men could build a practical machine which would synchronously generate electricity in large quantities by means of wind power.  And it proved that at some future time homes may be illuminated, and factories may be powered by this new means.” –Vannevar Bush, scientist and scholar, former dean of engineering at Massachusetts Institute of Technology, 1946

The idea, started almost on a whim. Consulting engineer Palmer Cosslett Putnam was bothered by high electric costs at his summer home on Cape Cod.  So in 1939, Putnam approached the S. Morgan Smith Company, manufacturers of hydraulic turbines, with his wind turbine design.  After five years of laboratory testing, a 2,000-foot mountain in southern Vermont was chosen as the site.  The 1.25-megawatt Smith-Putnam turbine was installed there on Granpa’s Knob, in Castleton, Vermont.  The twin-bladed 175-foot turbine was designed to withstand winds of up to 115 miles per hour and would generate enough electricity to light 12,500 100-watt light bulbs at full capacity.

On October 19, 1941, the Smith-Putnam turbine, in a 25-mph wind, fed electricity into the grid of the Central Vermont Public Service Corporation. A main bearing failure in 1943 shut the turbine down for two years (due to wartime shortages). It went back online in early March of 1945. On March 26, 1945, Palmer Putnam received a call that a blade had failed on the turbine. While not a surprise to those who worked on the project, the blade failure would mean the end of the project since wartime shortages made steel a luxury. Replacing the blade would not have been possible at the time. With coal prices 20% cheaper than the price of electricity produced by the wind turbine, the will to continue the project was not adequate and the project was dismantled.

Today, all that remains of the project are four cement footings where the wind turbine once stood. A chunk of steel on one of the footings is engraved with the names of the men who worked at the site and serves as a reminder of this experiment.