Bristol Composites Institute researchers overcome key design challenges in upscaling wind turbines for greater energy output
6 May 2022
Research from Dr Terence Macquart, Associate Professor Alberto Pirrera, and Professor Paul Weaver into the aerodynamic and structural engineering of extremely long (120 m plus) blades is supporting the development of larger wind turbines sought by industry.
Larger wind turbines are more cost effective in extracting power from the wind than their smaller counterparts. Hence, making wind turbines bigger has been, and continues to be, the dominant strategy to make wind energy more affordable. However, as rotor diameters continue to grow, blades become heavier and more flexible, presenting engineers with complex design challenges such as the trade-offs between weight, strength, and stiffness. More flexibility also means stronger interactions between a blade’s aerodynamic and structural behaviour. These interactions can be designed to be synergistic and so should be accounted for to maximise the cost-effectiveness of turbines and of the energy that they yield. The wind industry, however, still relies on sequential design methods in which the aerodynamic and structural disciplines are treated separately. To resolve this issue, the research team based at the Bristol Composites Institute and Aerospace Engineering Department of the University of Bristol has developed ATOM (Aeroelastic Turbine Optimisation Methods), a software suite that can design wind turbine rotors holistically considering multiple disciplines at once. This aero-servo-elastic MDO (Multi-disciplinary design optimization) suite enables engineers to develop lighter, better performing blades that reduce the cost of energy by deforming optimally to reduce the loads on the system while extracting more energy.
ATOM is now being used routinely by the Offshore Renewable Energy Catapult (OREC) to support industry and further innovate in this area. For example, recent wind turbines designed collaboratively by the UoB team and OREC have the capacity to operate at 15-20 MW rated power (see figure), far exceeding the industry call for 12-15 MW offshore turbines by 2025. ATOM is currently being used for several other blade projects at ORE Catapult (https://ore.catapult.org.uk/people/peter-greaves/, including:
- The Joule Challenge – where it will be used to develop a baseline blade design to assess loads for several new composite components in a 20MW floating wind turbine, as well as considering more advanced blade design philosophies.
- Carbo4Power – where it has been used to develop a structurally feasible baseline blade
- Cornwall Flow Accelerator – where it has been used to perform an aero-structural optimisation of blades which led to a 1.5% increase in annual energy production (AEP), 11% reduction in blade mass and a 2.3% reduction in levelised cost of energy (LCOE).
- SusWind – where it is being used to design five blade variants using different environmentally friendly materials and to assess how the change in material properties impacts material costs.
The research bares global significance contributing towards the push for more affordable, eco-friendly energy sources for a net-zero carbon economy and for energy security across many nations.
Part of the research leading to this work was funded by the Engineering and Physical Sciences Research Council under its SUPERGEN Wind Challenge 2015 Grant, EP/N006127/1, as well as the Wind Blades Research Hub, a joint collaboration between the University of Bristol and Offshore Renewable Energy Catapult.