Practical Expertise Exceptional Design

1. Practical ExpertiseExceptional Design

2. Benefits of Universal Blade Design Kyle K. Wetzel, PhD CTO, Wetzel Engineering October 28, 2015 SMART Wind Composites Virtual Meeting on Blade Design

3. WETZEL ENGINEERING • Engineering Solutions Developer • Clients on 4 continents • Wind Energy • > 50 custom blade designs • > 20,000 blades operating • Aviation • Towers • Engineering services to • OEMs • Owners and Operators • Insurance Companies • And others… 3

4. Universal Components – What do we mean? • Component that is engineered to work on multiple turbines • Minor adaptions may be required • Example – root fastener pattern • Adjusting pitch on a stall regulated machine

5. DW has evolved away from this reasonable practice • Aerostar 7.5-12m blades used on multiple machines in the 1980s • LM 13m blades used on multiple 200-300kW machines from 1990s through present – out of production now • LM19, 21, 23 used on multiple machines in the 500-800kW size – mostly now out of production • LM blades from 37 to 61m used on multiple utility-scale machines, particularly in Asia

6. Why Universal Components? • Standardization leads to savings through volume production • Reduced tooling amortization • Reduced engineering & R&D amortization – may be enabling for a higher level of engineering • Reduction in infant mortality issues • Reduction in value engineering costs

7. “What About My Highly Optimized Custom Rotor?” • Optimal design is driven by a balance of loads (which drive cost) and performance • Optimize your turbine around your rotor instead of your rotor around your turbine. • Many OEMs make up-front decisions about turbine configuration that hamstring the rotor performance • You can still distinguish yourself through the details of your turbine • Save customization for Phase 2 when your volume increases

8. Comprehensive Solution • Variable Speed & Pitch Regulation • Dramatic Improvement in AEP • Utility wind evolved from DW and DW got “left behind” technologically – time to catch up

9. Comprehensive Solution • Variable-speed pitch-regulated rotor is a point design • “Standard” TSR • Reasonable Loads • Performance is maximized subject to limits of loads • Will fit on any machine • You cannot do better

10. Example -- • 14.5m Blade for a 100kW pitch-regulated turbine – 30.0m diameter • Cpmax=0.490 at TSR=9.0 • Class IV Performance • AEP = 324MWhr/yr • Capacity Factor = 37%

11. Example -- • Recover fixed cost in 3 years • Engineering = $300k • Cert & Testing = $225k • Tooling Cost = $325k • Process Engineering = $75k • Facility cost = $150k/yr • Learning Curve Factors • Factory Utilization • 1,000-blade mold life • Cost per set • 300 sets/yr = ~$29,500 /set • 30 sets/yr = ~$49,500 /set • 1 set = ~$1,100,00

12. Catch-22: • Blade OEM cannot commit to off-the-shelf solution without sufficient demand • Turbine OEMs won’t commit to an off-the-shelf blade unless it’s available • Solution: Collaborative development of universal solutions Which comes first: supply or demand?

13. Standard Designs • 11m for 50kW • 14m for 100kW • 18m for 250kW • 22m for 500kW • 26m for 750kW

14. Wetzel Engineering, Inc. Office 821 Grand Ave Pkwy #410 Pflugerville (Austin), TX 78660 Plant 3914 Gattis School Rd #103 Round Rock, TX 512-989-9194 www.WetzelEngineering.com info@WetzelEngineering.com