Wind energy research and development began at UMass Amherst under the leadership of program founder, Professor William E. Heronemus. Professor Heronemus, along with a number of other faculty, began looking into a number of areas related to wind energy potential, including ways to quantify the wind energy resource, optimizing the design of wind turbines for electrical production, offshore wind energy potential, and ocean thermal energy conversion. Very few people worldwide were looking into these areas at the time, and many of Professor Heronemus’s concepts which are widely accepted today (such as the vast potential of offshore wind) were considered visionary at the time
(The following was adapted from Chapter 24, Emergence of Wind Energy: The University of Massachusetts, written by J. F. Manwell, in Wind Power for the World, edited by Preben Maegaard, Anna Krenz and Wolfgang Palz, Pan Stanford Series on Renewable Energy, 2013
History of the Wind Energy Program at the University of Massachusetts Amherst
Although wind energy had a long history in the United States, by the 1960s it appeared that wind energy was no longer relevant. At that time fossil fuels were cheap and plentiful and nuclear power was “too cheap to meter”. Unnoticed by many, however, the seeds for wind energy’s renaissance were already germinating. As of 1956, M. K. Hubbert was already predicting that oil’s days were numbered. With the publication of Rachel Carson’s book Silent Spring in 1962 many people became aware of the environmental consequences of industrial development. By 1970, the first Earth Day reflected the beginning of the new awareness. As it turned out the University of Massachusetts in Amherst (UMass) provided one the fields where some of these seeds took root.
The Renewable Energy Vision of William Heronemus For many years UMass was an agricultural school and the transformation to a university did not begin until 1947. The 1960s witnessed a significant expansion, with construction of many new buildings and the hiring of many more professors. For the future of renewable energy, one of the most significant new hires (1967) was Capt. William Heronemus, who had just retired from the US Navy. His charge was to oversee the establishment of an Ocean Engineering Program. He did in fact do that, but of most significance was that he brought with him a vision of an energy future which was radically different than that which was most people were expecting. In 1971 he wrote the following:
“In the immediate future, we can expect the ‘energy gap’ to result in a series of crises as peak loads are not met. The East Coast will be dependent on foreign sources for most of its oil and gas. The environment will continue to deteriorate in spite of ever increasing severity of controls. Air pollution, oil spills and thermal pollution are likely to be worse, not better in 1985. In the face of the continuing dilemma: power vs. pollution, a third alternative [to nuclear and fossil energy] must be sought. It may be found in the many and varied non-polluting energy sources known to exist in the United States or its offshore aggregate. These energy sources, tied together in a national network, could satisfy a significant fraction of our total power needs in the year 2000. That favorable outcome could result from a serious research and development effort started now and a design and construction effort started in 1985.”
William Heronemus’s essential vision was no less than to completely replace conventional forms of energy, fossil as well as nuclear, with renewable energy sources. The sources he had in mind were solar, wind, and ocean thermal differences. Together with other faculty members, Prof. Heronemus established the Energy Alternatives Program at UMass. This included participants from mechanical, civil, industrial and electrical engineering. The program was dedicated to working out the details of this paradigm and to educate the engineers of the future who would help make this vision a reality.
One of the key technologies in this future was to be offshore wind energy. This was a remarkable idea, especially in so far as there were barely any working wind turbines on land at that time. Because there were so few working turbines, Heronemus proceeded to learn as much as he could about the most relevant experience and vision of others. These included Albert Betz, Hermann Honnef, and Ulrich Hütter of Germany, Poul la Cour and Johannes Juul of Denmark, E. W. Golding of the UK, and Percy Thomas and P.C. Putnam of the United States. To their earlier concepts he added support structures for multiple rotors, floating turbines, fleets of such turbines, and a hydrogen storage system to firm the power.
These concepts were ahead of their time, and until very recently there were no offshore wind turbines in the United States. Many of the ideas were fundamentally sound, however, and are still relevant today.
Significance of the First UMass Wind Turbine, WF-1 Because of the paucity of actually existing wind energy converters, Heronemus proceeded to develop a relatively small wind turbine, which would be useful in and of itself and which would also serve as a platform to investigate the technology for larger turbines of the future. This turbine was known as WF-1 (short for Wind Furnace-1) and was conceived of as the core of a residential wind heating system.
The WF-1, designed and constructed at UMass between 1973 and 1976, ended up being historically one of the most significant wind turbines from that era. Although small by modern standards, at the time of its completion in 1976 it was the largest operating wind turbine in the United States. In many ways, the WF-1 has heavily influenced the entire modern global wind industry: the first generation of American wind-energy engineers was 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: three fiberglass blades, near-optimal blade-shape, blade pitch regulation, variable speed operation, and computer control.
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 1970s, 1980s and even 1990s. By Robert Righter’s (Wind Energy in America: A History, University of Oklahoma Press, 2008) reckoning, the WF-1 marked the beginning of the modern wind-electric era. Earlier wind-electric generators included small generators such as the Jacobs Windcharger, as well as larger models (some purely experimental), such as the Brush turbine, the Russian Balaclava (1930s), the Smith-Putnam (1930s), the Danish Gedser (1950s), and the German Hütter turbines (1960s).
The WF-1 was the forerunner of the turbines built by US Windpower of Burlington, MA. US Windpower went on to become the largest and most successful (for a while) wind turbine manufacturer in the United States. US Windpower eventually became Kenetech Windpower. Many of Kenetech’s assets were acquired by Zond Systems, in turn purchased by Enron Wind, and then finally purchased by General Electric, which is now the major wind turbine manufacturer in the United States.
The WF-1 was paired up with a building known as the Solar Habitat, located on the UMass Amherst campus. This facility was designed to demonstrate that a number of energy efficient building practices, such as solar hot water heaters, could be incorporated into a popular housing style, the ranch house. The WF- 1 successfully demonstrated that wind heating could work, but the concept of a “wind furnace” never caught on. Relative to grid quality electricity, space heating was not economical, and subsequent technological advances and regulatory changes favored the direct production of electricity from wind power.
Many of the students who worked on WF-1 went on to work for major wind turbine manufacturers in the United States when the industry was just beginning. At least three students who worked on the WF-1 took jobs with US Windpower very early on. Later on others joined Northern Power Systems, Hamilton Standard, Kenetech, Zond, Carter, Fayette, Enron Wind, to name just a few. Two of the original WF-1 students were principals of ESI, a one-time major manufacturer of wind turbines. Many veterans of the WF-1 project went on to work in other sectors of the wind energy industry, such as at GE Wind (now GE Renewables), the DOE’s National Renewable Energy Laboratory, Northern Power Systems (in VT), and at Second Wind (now Vaisala) in Somerville, MA).
During the years after the WF-1 was erected at UMass Amherst, wind energy in the United Stated went through a succession of booms and busts, depending on the attitudes and inclinations of administrations in Washington and the governors in a few states. Wind energy technology began to go through its own evolution. Some of the turbines from those days were patterned after earlier designs; others were based on wishful thinking. Regardless of their provenance, however, it must be said that many of the turbines did not work very well or for very long.
Engineering and Education for a Renewable Energy Future
In order to make the vision of a renewable energy future a reality it became quite clear that the turbines needed to be more reliable and the way they could be integrated into a complete energy system needed to be better thought out. This all required serious engineering at the highest level. Turbines must be able to extract energy from the wind, convert it to a usable form, and deliver the energy to its point of use, all with structures that are light, resilient, and inexpensive, and within the confines of an electrical system which is required to supply firm power on demand. The fluctuating nature of wind, the structural response of the turbines, and the need for very long lives, imposed design requirements that were very challenging. These requirements were not well understood in the 1970s. It also became apparent that to make a wind energy system function properly requires expertise in many areas, including meteorology, aerodynamics, structural mechanics, materials, control, mathematical modelling, machine design, electrical systems and cost engineering, to name a few.
What setting is better for contemplating such problems than a university? Once I finished my Ph.D., it seemed to me that the most interesting and useful thing I could do would be to continue and expand the renewable energy education and research program at UMass that Prof. Heronemus had started, so that is what I set out to do. This whole endeavor has had many twists and turns over the last 30 years, but it has resulted in opportunities for many students to learn about wind energy and to undertake research that had real significance.
The UMass Amherst wind energy program has been active in wide range of research areas, including hybrid power system design, wind resource analysis, wind turbine operation and design, and offshore wind energy, environmental impact and energy policy. In the paragraphs below, I will summarize our work in two of these areas: hybrid power systems and wind resource assessment. Hybrid energy systems have been defined as “combinations of two or more energy conversion devices (e.g., electricity generators or storage devices), or two or more fuels for the same device, that when integrated, overcome limitations that may be inherent in either.” In our work at UMass, we have focused particularly on those hybrid systems, which included, at least, wind turbines and diesel generators; these are usually referred to as “wind/diesel systems”.
Hybrid power systems are intrinsically interesting because (1) they are potentially quite useful to many people in the world with limited access to conventional electricity and (2) they are technically quite challenging. They are also interesting because they serve as microcosms for some of the same issues that are now being encountered as large amounts of renewable generation are added to much larger central power networks.
Work at UMass Amherst has involved a number of topics in this area. The key question was how to provide a very large fraction of the electricity in an isolated electrical network from a fluctuating resource, such as is the natural wind. We considered fluctuations over all time scales ranging from seconds to seasons. The studies we undertook included systems engineering as well as time domain and frequency domain simulations. To study the electrical aspects of such systems, we designed and built a complete hybrid power system hardware test bed. This test bed included a wind turbine simulator (using a purpose-built DC motor–AC generator with computer control), diesel generators, electrical load simulator, rotary converter (for voltage support), optional battery storage and specialized controllable devices (for power control and/or frequency control).
The hybrid system studies lead to the development of the Kinetic Battery Model, which has since become used throughout the world in a wide range of battery applications. Further development and expansion of this model is still continuing at the present time. One of the major accomplishments of our hybrid power system work was the development of the Hybrid1 computer code and its successor, Hybrid2, which employs both time series and statistical techniques. Hybrid2 became the standard for detailed engineering analysis of hybrid power systems and it is still widely used throughout the world.
Our work with hybrid systems has also been extended to include load management via distributed space heating, desalination of sea water, and the use of hydrogen as a storage medium. The desalination work has recently been further extended to a detailed study of a distributed generation community scale desalination project.
Some of our earlier work with hybrid power systems was reflected in the book Wind Diesel Systems: A Guide to the Technology and its Implementation (Cambridge University Press, 1994). This book was one of the key outputs of an International Energy Agency working group in which we were privileged to participate. Wind resource analysis in the wind energy field has two very broad purposes. The first has to do with characterizing the conditions which wind turbine itself must be designed to accommodate. The second has to do with the performance of the turbine (in terms of energy generation). Topics of interest in the first area have to do with turbulence (both temporal and spatial) and extreme events. Topics in the second area have to do variations in the wind that result in short term electrical fluctuations and more slowly fluctuating mean electrical power.
In the area of wind resource analysis, our work has made use of what has by now become traditional data collection with anemometry (for both mean wind speed and turbulence investigations), through the use of SODAR (SOnic Detection And Ranging), and most recently LIDAR (LIght Detection And Ranging). For the processing of wind data, our early work included some pioneering use of time series analysis, modelling with long term statistics, spectral analysis, and data synthesis techniques (using Markov processes).
Recently we undertook in studies of the portion of atmospheric boundary layer in which the largest wind turbines of today operate (40 m to 150 m above the ground). These studies utilized instrumentation installed at multiple levels on very tall towers, as well as SODAR and LIDAR. One of our projects involved monitoring the wind offshore in Nantucket Sound.
One of our most interesting projects was the creation of a wind turbine test facility at the top of mountain ridge not far from the University. The heart of the facility was an ESI turbine, which was originally installed in California. We brought the turbine back to Massachusetts and completely refurbished it before re-erecting it on the ridge. The turbine was challenging in many ways—it had a two bladed, down-wind, teetered rotor, for example. The blades were stall regulated, the nacelle was free to yaw as the wind direction change, and the control system was initially relatively primitive. This facility provided an excellent opportunity for our students to study the behavior of a real turbine in a complex environment and to design, implement and test a variety of modifications.
Finally, we have developed a significant wind energy educational program at UMass. For many years, we have offered a course on the fundamentals of wind energy. This course is directed at senior level or graduate students in Mechanical Engineering and it covers the most important topics in wind energy engineering. A second course is Wind Turbine Design. It builds upon the first one, and provides in-depth examination of how turbines should be built. Our experience with these two courses provided the background for our textbook Wind Energy Explained: Theory, Design and Application (Wiley, 1st ed., 2001; 2nd ed., 2009). Finally, a recently developed course on offshore wind energy provides the engineering background for this newly developing field.