Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. The Sandia Legacy VAWT Research Program Dale Berg Wind Energy Consultant Formerly Wind & Water Power Technologies Sandia National Laboratories [email protected](+1) 505-235-6392 Scientific and Technological Challenges In Offshore VAWTs 7-9 September 2016 Delft, NL
37
Embed
The Sandia Legacy VAWT Research Program...2016/09/07 · VAWT model Delft University of Technology 6 Challenges in Offshore VAWTS 7-9 Sept 2016 Sandia Legacy VAWT Program (continued)
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,
for the United States Department of Energy’s National Nuclear Security Administration
under contract DE-AC04-94AL85000.
The Sandia Legacy VAWT Research Program
Dale BergWind Energy Consultant
Formerly
Wind & Water Power Technologies Sandia National Laboratories
Federally-funded development of large VAWT (part of NASA MOD program) started in ’80, but terminated in ’81 (MOD 6V)
Remainder of Tech Transfer efforts were limited to Sandia support of private industry efforts (enticed by state and federal tax credits and California SO-4 contracts)• CA SO-4: utility companies committed to long-term purchase of wind
energy at high prices to hedge against anticipated oil price increases
DelftUniversity ofTechnology
Challenges in Offshore VAWTS 7-9 Sept 201610
Sandia Legacy VAWT ProgramTechnology Transfer (continued)
Alcoa built a few “123-82” machines (’82-’83)• based on “Low-Cost” design
• 3-bladed Darrieus with guy cables
• extruded aluminum blades
• Southern California Edison machine failed on start-up due to controller problem
• quit the wind business
Forecast Industries (later VAWTPower)• based on “Low-Cost” design
• 2-bladed Darrieus with guy cables
• extruded aluminum blades
• only 15-20 built
• structural resonance problems from the start; quickly went bankrupt
DelftUniversity ofTechnology
Challenges in Offshore VAWTS 7-9 Sept 201611
Sandia Legacy VAWT ProgramTechnology Transfer (continued)
FloWind• based on “Low-Cost” design (17-m and 19-m versions)
• 2-bladed Darrieus design with guy cables
• extruded aluminum blades
• built over 520; 511 sited in two California wind areas (San Gorgonio Pass and Altamont Pass) (’83 – ’85)
• largest and most successful wind turbines available in the mid ’80s
• one of the largest wind companies of that era
• fatigue of the blades (common to most HAWTs as well) led to wide-spread blade issues starting in ’86 or so
didn’t understand importance of fatigue
didn’t understand fatigue properties of aluminum
didn’t understand wind loading environment
FloWind 17-m Turbines
DelftUniversity ofTechnology
Challenges in Offshore VAWTS 7-9 Sept 201612
Sandia Legacy VAWT ProgramTechnology Transfer (continued)
Paraphrasing the words of Paul Gipe, well-known critic of VAWT technology*:
“By the end of 1985, FloWind….had installed 95 MW of its signature product (equivalent to 15,000 Quiet Revolution’s 5-meter).”
“At their most productive, FloWind’s fleet generated 100 million kilowatt hours (per year) – enough electricity for nearly 20,000 California homes.”
“FloWind’s 17-meter model was rated at 142 kW at a wind speed of 38 mph (17 m/s), their 19-meter model was rated at 250 kW at a wind speed of 44 mph (20 m/s).”
“For comparison, a conventional wind turbine 18 meters in diameter would typically be rated at 100 kW and a 21-meter turbine would be rated at 150 kW. Thus, the FloWind turbines were overrated in comparison to their peer by at least 50%.”*Paul Gipe, 2009, “Wind Energy Basics Revised: A Guide to Home- and Community-scale Wind Energy Systems”
DelftUniversity ofTechnology
Challenges in Offshore VAWTS 7-9 Sept 201613
Sandia Legacy VAWT ProgramTechnology Transfer (continued)
FloWind (continued)• some machines survived for years in a very, very aggressive site known
as Horned Toad Ridge several different makes of HAWTs had quickly failed there
very high sustained, highly turbulent winds
energy capture for some of these VAWTs was significantly higher than any HAWTs were achieving
FloWind 19-m
Turbines
• 511 of these machines continued to operate through 1997 (output dropped significantly after ’93 as more and more problems occurred)
DelftUniversity ofTechnology
Challenges in Offshore VAWTS 7-9 Sept 201614
Sandia Legacy VAWT ProgramBlade Design
All early turbines (HAWTs and VAWTs) used NACA airfoils
Sandia optimization studies (Kadlec) revealed changing airfoilcharacteristics could yield lower COE• lower and wider drag bucket
• sharp stall
• reduced sensitivity to roughness
Worked with Prof. Gregorek at Ohio State to design Sandia symmetric airfoils (’82 time frame)• similar to previous NACA natural laminar flow (NLF) designs
• SNL 0015/47, 0018/50, 0021/50
• extrusion method of blade fabrication makes NLF achievable
NLF Profile
DelftUniversity ofTechnology
Challenges in Offshore VAWTS 7-9 Sept 201615
Sandia Legacy VAWT ProgramLarge Machines
Sandia started the MW-size MOD 6V in ’80 • DOE effort to drive large machine technology
• Sandia built up large staff
• cancelled when tax credits implemented
Sandia started work on 34-m (500 kW) in ‘84• not a commercial prototype, but a research machine