Sandia’s Wind Energy Technology Department seeks opportunities to advance the current state of the art in rotor technology such that rotors can capture more energy, more reliably, with relatively lower system loads – all at a lower end cost. The blades make up about 14% of the capital cost of a full turbine (Tegen, 2013), but they are responsible for practically 100% of the energy capture in a wind plant. They are responsible for all the steady and dynamic loads which drive the design and cost for the remainder of the turbine system – hub, shafts, bearings, gearbox, nacelle bedplate, tower and foundation. Optimal relationships between rotor structures, rotor aerodynamics, and the rest of the turbine system are complex. The wind industry has evolved over time to provide competitively low cost of electricity using increasingly optimized systems.
Sandia rotor innovation activities are directed primarily toward two approaches
1) Quantitative evaluation and reporting of rotor innovation concepts using numerical studies. Examples include the Sandia 100m blade design progression and the Sandia investigation of the effects of increasing maximum tip velocity on optimum rotor designs. Complete and accurate numerical design methods are critical to our work in this area. Projects result in public, detailed models and tools that are beneficial to the entire wind energy research community.
2) Design and field test of rotor hardware for validation of rotor innovation concepts or hardware created to support goals of larger experimental campaigns, such as the DOE Atmosphere-to-electrons (A2e) Initiative. Work in this area leads to public field test data which is used to improve important simulation and analysis tools, enabling effective evaluation of future innovations.
Sandia’s Wind Energy Technologies Department creates and evaluates innovative large-blade concepts for horizontal-axis wind turbines (HAWTs) to promote designs that are more efficient aerodynamically, structurally, and economically. Recent work has focused on developing a 100 m blade for a 13.2 MW HAWT, a blade significantly longer than the largest commercial blades that existed at the beginning of this project (~60 m long).
Selected design studies:
- Sandia 100m blade design progression
- Sandia investigation into tradeoffs in rotor designs due to increasing tip velocity
Tegen, S., Lantz, E., Hand, M., Maples, B., Smith, A., and Schwabe, P. “2011 Cost of Wind Energy Review,” National Renewable Energy Laboratory: NREL/TP-5000-56266, 2013.