The UMass Wind Turbine WF-1, A Retrospective

J.F. Manwell
J.G. McGowan
F.S. Stoddard


In the mid 1970's a 25 kW wind turbine was designed, built and installed at the University of Massachusetts at Amherst. Known as the WF-1, it is historically one of the most significant wind turbines from that era. Although small by modern standards, at the time of its completion it was the largest existing wind turbine in the US and perhaps the largest operating turbine in the world.

In many ways, the WF-1 has heavily influenced the entire modern global wind industry: the first generation of American wind engineers were trained by working on its design and operation, and many of the WF-1's innovations appear in modern turbines. Today's "mature" wind turbine design bears what was once new on the WF-1: 3 blades, near-optimal blade-shape, fibreglass blades, pitch regulated, variable speed operation, and computer control.

WF-1 Turbine Details and Significance

The WF-1 could be considered the first "modern" US wind turbine, and in many ways it was more advanced than many later models of the late 1970's, 1980's and even 1990's.

  • The turbine has 3 blades and a diameter of 32.5 ft. The blades have a nearly optimum shape; a first or nearly so.
  • The rotor turned at variable speed, and with a near constant tip speed ratio so that it was maximally efficient over a wide range of wind speeds - also perhaps a first.
  • Power control was done by changing the blade pitch, another distinction of innovation.
  • The turbine was computer-controlled by a computer and was probably the first in the world to be so controlled.

By Robert Righter's (1996) reckoning, the WF-1 marked the beginning of the modern wind-electric era. Earlier wind-electric generators included small generators such as the Jacobs and Windcharger, as well as larger models (some purely experimental), such as the Brush turbine, Russian Balaclava (1930.s), Smith-Putnam (1930.s), Danish Gedser (1950.s), and German Huetter turbines (1960.s).

The WF-1 was the forerunner of the turbines built by US Windpower of Burlington, MA. US Windpower went on to become the most successful (for a while) wind turbine manufacturer in the United States. US Windpower eventually became Kennetech Windpower. Many of Kennetech's assets were acquired by Enron Wind, and then in turn by GE Wind, which is now the major wind turbine manufacturer in the US.

The WF-1 in the UMass Wind Research Program

Shortly after the UMass renewable energy program was founded by Prof. William Heronemus in the early 1970's, the WF-1 wind turbine became the heart of it. The turbine took its name from its original purpose: energy in the winds would be converted to heat for use in space heating of residential buildings.

In particular, the WF-1 was paired up with a building known as the Solar Habitat. This building, in turn, was designed to demonstrate a number of energy efficient building practices, such as solar hot water heaters. The wind furnace successfully demonstrated that wind heating could work, but the concept of a "wind furnace" never caught on widely. Relative to grid quality electricity, space heating had poor economics, and subsequent technological advances and regulatory changes favored the direct production of electricity from wind power.


The wind furnace project was initiated by Prof. William Heronemus, then in the Civil Engineering Dept. Prof. Heronemus was also a naval architect and a captain in the US Navy, with extensive experience on nuclear submarines. He was also the first person to propose offshore wind projects for New England; his concepts called for floating support structures, relying heavily on his navy experience, rather than the bottom mounted turbines currently in use. As far as can be presently determined, he was also the first to propose a "hydrogen economy," based on hydrogen produced from the electrolysis of sea water, using wind turbines as the source of the electricity. In sum, Prof. Heronemus is widely considered to be the father of modern American wind energy. The concepts he proposed were often considered visionary at the time, but he lived to see many become reality. He died in 2002.

Other UMass faculty involved with the wind furnace project included the following:

  • Prof. Jon McGowan, Mechanical Engineering: solar thermal and wind heating system design
  • Prof Duane Cromack, Mechanical Engineering: aerodynamic design and turbine operation
  • Prof. Robert Kirchhoff, Mechanical Engineering: fluid mechanics and dynamic response
  • Prof. Curtis A. Johnson Agricultural Engineering: design of the Solar Habitat
  • Prof. Dale Schoekels, Electrical Engineering: electrical power systems
  • Prof. F. C. Kaminsky, Industrial Engineering
  • Prof. Merit White, Civil Engineering: Structural issues
  • Prof. A. Chajes, Civil Engineering, Tower design
  • Prof. F. Dzialo, Civil Engineering
  • Prof. R. V. Monopli, Electrical Engineering: Electrical power systems
  • R. M. Glorsioso
  • P. A. Mangarella

A great number of students were involved in the design, construction or operation of the WF-1. Most of them either earned their MS or PhD degrees in connection with their work on the project. Some of those students include:

  • Forrest (Woody) Stoddard: wind turbine design, fabrication, dynamic response
  • James Sexton: turbine hub design
  • Charles P. (Sandy) Butterfield: blade pitch control
  • Dan Handman: control system design
  • Fred Antoon: mechanical design
  • Fred Perkins: blade fabrication
  • Michael Edds: electrical power system design
  • Bruce Johnson: tower dynamics
  • Paul Lefebvre: rotor design
  • Brian Kuhn: draftsman for WF-1 drawings
  • Ted Van Dusen: turbine configurations
  • Louis Manfredi: turbine construction and operation
  • Ghazi Darkazalli: system integration
  • James Manwell: system analysis, performance, and dynamic response
  • Walt Musial: rotor aerodynamics
  • Paul Murphy, wind resource studies
  • Louis Socha: solar system performance
  • Ward Wells: heating system design
  • David Kresse: drive train modifications
  • Derek Petch: drive train modifications
  • Paul Palo
  • Benjamin Bell
  • Brian McNiff
  • Paul Wendelgass
  • Jay Turnberg
  • Walter Sass
  • Patrick Quinlan
  • Brian Smith

Many of the students who worked on WF-1 went on to work for major wind turbine manufacturers in the US when the industry was just beginning. At least 3 students who worked on the WF-1 worked for US Windpower very early on: Louis Manfredi, Forrest (Woody) Stoddard, and Dan Handman. Others joined Kennetech Windpower, Zond, Fayette, Enron Wind, and Second Wind. Two of the original students (Sandy Butterfield and Jim Sexton) were principals of ESI, a one time major manufacturer of wind turbines. Many veterans of the WF-1 project still work in the wind industry, such as at GE Wind, the DOE's National Renewable Energy Laboratory, Northern Power Systems (in VT) and at Second Wind (in Somerville, MA).

Present Status

The turbine was dismantled in the first week of October 2004. It now sits in the RERL lab being prepared for storage and then future transportation to the Smithsonian Institution in Washington D.C. 

Comments? Questions? Corrections, because you were there and know what really happened? More photos? Please send correspondence to Jim Manwell, the current director of the Renewable Energy Research Lab at UMass.

Documentation, References

The WF-1 was highlighted (p. 45) in David Inglis' book, Wind Power and Other Energy Options, published in 1978. It is also discussed in Torrey (1976), Marier (1981), Naar (1982), Righter (1996), Berger (1997), and Gipe (2004). Numerous project reports, M.S. and Ph.D. theses also document various aspects of the Wind Furnace project.

Berger, J. J., Charging Ahead: The Business of Renewable Energy and What it Means for America, Henry Holt and Co., New York, 1997.

Gipe, Paul, Wind Power: Renewable Energy for Home, Farm, & Business, 2004

Heronemus, W. and Cromack, D., Investigation of the Feasibility of Using Windpower in for Space Heating in Colder Climates, Phase II, Final Report for the Period Ending June 30, 1977, ERDA/2365-77/2, UC-60, UM-WF-PR-77-2, University of Massachusetts, 1977.

Inglis, David, Wind Power and Other Energy Options, 1978

Marier, Donald, Wind Power for the Homeowner, Rodale Press, Emmaus, PA, 1981.

Naar, The New Wind Power, Penguin Books, New York City, 1982

Righter, Robert, Wind Energy in America, Univ. of Oklahoma, 1996

Torrey, Volta, Wind Catchers American Windmills of Yesterday and Today, Stephen Greene Press, Brattleboro, VT, 1975

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