For one week following each TAP Webinar, which is hosted by the U.S. Department of Energy Technical Assistance Project (TAP) for state and local officials, you are invited to ask questions of the presenters, enter comments about the topic of the presentation, and share your thoughts with others. You can find copies of presentations from the April 28 Webinar in PDF format and audio files in MP3 format and background materials and reports in the TAP Webinar archive.
Question:
What technical innovations to you see unfolding in the future development of midsize wind turbines?
Trudy Forsyth Answers:
I see taller towers, longer blades combined with new direct-drive generators or new gearbox solutions with new generators, and use of new high-tech materials. For example, there are new magnetic materials coming onto the horizon along with strategies to reduce the copper needed in generators. And there are new composite materials for blades and other components. For more information about this topic, see the Midsize Wind Turbine Research page on the National Renewable Energy Laboratory (NREL) website.
Nicholas DiPasquale asks:
Is there a capacity limit to community wind projects? For example, the University of Delaware College of Earth, Oceans and the Environment is installing a 2-MW wind turbine and will share power with the Town of Lewes, and this is considered a community wind energy project.
Trudy Forsyth responds:
My understanding is that the American Wind Energy Association (AWEA) Community Wind Committee has set an upper limit for community wind projects at 20 megawatts (MW). Given that definition, we would consider the 2-MW project you describe to be a community wind project. In this webinar, I focused on the lack of availability that exists for turbines between 100 kilowatts (kW) and 1 MW, leaving some community wind projects without turbines. However, there are definitely larger community wind projects out there, some using larger turbines. You may want to check with AWEA or Windustry—a membership organization that advocates for wind energy projects, especially in the Midwest—for more information.
David Hurwitt asks: The ICF report talks about $2.57/watt installed cost being the trigger price for real market growth. Do you see conventional midsized turbines ever being able to hit this price? How far do you think they are now?
Trudy Forsyth responds:
An installed cost point of $2.50/Watt does seem aggressive today, but both good policy and higher volumes of midsize turbine production will help drive down the costs of midsize turbines. I think the better question is about the levelized cost of energy—cost per kilowatt hour (kWh) produced—instead of cost per rated turbine capacity. These cost of energy numbers will change as the market and manufacturing capacities develop over time.
Don McCall, sales director, American Resource & Energy Company asks:
I realize inverters have a Underwriters Laboratory (UL) ratings, but is this required for midsize wind turbines as well?
Trudy Forsyth responds:
UL and other electrical certification organizations already certify wind power generating equipment for electrical safety to their standards (UL-1741 or IEEE-1547). Broader certification requirements that go beyond electrical safety are today only beginning to show up for small wind turbines, and the Small Wind Certification Council has started to certify turbines in the United States. There is also a move to develop tower standards for large and small turbines that is just getting under way. Finally, there is a new UL activity to develop electrical standards for small wind turbines, large wind turbines, and converters. I'll guess that midsize turbines and associated equipment will fall under the large wind standard when it is finalized.
Michael Greis asks: Is there a database or listing of midsize or community wind projects? Any reports with such a listing? I'm interested in a sample with sizes, total costs, user types, etc.
Trudy Forsyth responds:
Windustry, a nonprofit organization in Minnesota focused on community wind and educating interested stakeholders on community wind, does have a database showing community wind projects in the US, see I'm not sure that all of the information you are looking for will be included in this database but you can see that they are planning a series of Community and Small wind workshops later this year. Read the Community Wind pages on the Windustry website.
Jorge el Koury asks:
Are avian studies more critical for midsize wind turbines that for utility-scale wind power plants?
Trudy Forsyth responds:
There haven't been any incidences with avian and or bat interaction on individual midsize turbines, but environmental evaluations or assessments may be required by state and local permitting agencies.
Kirk Holmes asks:
The photos show significant proximity to structures where people work and live. What are the general setback recommendations of midsize systems as presented?
Trudy Forsyth responds:
This is a good question because there have been no specific ‘rules of thumb' developed to date. In general, turbines need to be far enough away to not effect safety and far enough away that the wind resource is not highly influenced by blockages in the prevailing winds. Please keep in mind, however, that photos of panoramic vistas can sometimes distort the actual turbine locations compared to nearby structures, depending on the lens used on the camera. In other words, I believe these photos make the turbines look much close to structures that they really are.