Wind energy now forms a vital part of the economy in many global regions and is expanding into new arenas. The Chinese market is strong, the USA is recovering and with emerging nations now increasingly adopting renewable energy solutions, global growth is predicted to continue at a steady rate with a doubling of installations from 2013 to 2018 (Steve Sawyer, GWEC Secretary General 2014). This will drive demand for turbines and blades worldwide.
Wind turbines are now using well-established technology and with decades of experience the blade designers and manufacturers are constantly reviewing the materials, manufacturing and performance of blades. A leading blade maker, LM Windpower, is looking at the blade technology of the future and will give the opening address at AMI’s international conference on Wind Turbine Blade Manufacture 2014, 1-3 December in Dusseldorf, Germany. This will be followed by Vestas Wind Systems talking about the industrialisation of blades including modularisation, standardisation and fabrication.
There are standards for blades set by a variety of institutes and DNV will outline their requirements. The testing process is extensive including components. In new developments, Zoltek has been testing thick unidirectional composites with DTU Wind and Momentive Specialty Chemicals has conducted experiments to qualify bonding paste resins.
Design is critical to performance. Acciona Windpower has examined the shear stress concentration at rotor blade bonding joints and Aerodyn Energiesysteme has studied the static structural design of blades. In China, the Lianyungang Zhongfu Lianzhong Composites Group is developing a bamboo blade together with Sinoi. Meanwhile the UK is funding research into ultra-large blades at Blade Dynamics.
In the US the Department of Energy has supported studies into advanced wind composites manufacturing and TPI Composites will present the final results. Pontis Engineering has been involved in setting up blade factories and has worked on advanced monitoring of the manufacturing process. In Denmark Professor Povl Brondsted is studying the influence of resin consolidation and curing cycles on the shrinkage and residual stresses in wind turbine blades, while EUROS is using infusion simulation to improve blade manufacturing. Gurit has examined the technical and economic aspects of the production processes for spar caps and Ahlstrom Glassfibre has new non-stitched unidirectional reinforcements for vacuum infusion.
The industry is changing to meet new challenges such as upgrading of existing wind farms with higher energy production blades, like those from ETA Blades, and increasing the power output of offshore turbines to minimise the installation costs.
Reliability is the key word in renewable energy and EDP Renewables will describe the lessons that they have learnt as an end user of wind turbines. Nordex is focusing research on anti-icing technology alongside lightning protection – two primary issues with weather. Wetzel Engineering works with wind farmers and has studied the main causes of blade failure and strategies for minimising the problems. In terms of maintenance, Sika Services has material for fast surface repairs.
AMI’s Wind Turbine Blade Manufacture 2014 provides a debating forum for the wind energy composites industry and attracts wind farmers, turbine manufacturers, blade suppliers, researchers, testing laboratories and the materials and equipment supply chain from across the world.