Recognition of the value of wind energy as a low cost, clean source for electricity is creating major new business opportunities for manufacturing and materials innovation. Increasing efforts are being made all across the globe in generating power from renewable resources. Wind energy is gaining over the years, reaching 120 gigawatts by the end of 2008, representing only 1.5% of the global energy requirement. However by 2020, about 12% of the total energy could be generated from wind. In the past two decades, wind energy has made quantum progress- a single modern wind turbine produces 180 times more electricity annually at less than half the cost per kWh than its equivalent of 20 years ago. In fact the future looks really bright for wind energy and in the next 10 years, it is set to emerge as one of the fastest growing segment within the energy industry. By the end of 2017, it is estimated that over 718,000 MW of wind power will be installed, and the United States and China would be leading from the front, as per Aruvian R’search. Wind energy is on the rise as a climate friendly source of energy. Larger rotor blades are constantly increasing the power output of modern wind turbines. The stresses and strains to which rotor blades of wind turbines are exposed at 90 meters above the ground are truly immense. Reaching top speeds of up to 300 km/hour, forces are exerted on blade tips which make them bend for more than a meter. Weather conditions such as snow, rain, heat and UV radiation also take their toll on the blades. BASF is supporting the manufacturers of these mighty machines by supplying innovative epoxy resin systems for highly resilient, fiber-reinforced components and coatings for rotor blades. The longevity of these wind energy plants is a key factor in improving the economic efficiency of wind power as a climate friendly source of energy. The use of wind power presents a challenge for both technology and materials, on which it places the highest demands. Rotor blades need to be very tough and weather resistant to survive operating times of 20 years. Modern rotor blades are made of glass or carbon fiber mats bonded with epoxy resin systems to give them strength. The innovative system has been approved by certification agencies for wind energy plants including the worldwide leading Germanischer Lloyd AG. Another important factor besides the technical design of the rotor blades is how well their coating withstands environmental impacts. The special coatings developed by BASF's subsidiary are flexible to minimize the risk of stress cracking and do not flake off when the blades bend, considering that the tips of a rotor blade can vibrate back and forth for more than a meter. The high-tech coatings are based on the special plastic polyurethane. More than 25,000 rotor blades with Relius coatings are now spinning in the wind and have been defying the forces of nature for years. Innovative epoxy resin systems for high-performance rotor blades Larger rotor blades have increased the output of modern wind turbines. Composites based on epoxy resins have become the material of choice in fabricating such rotor blades. Most recently BASF has been supplying Baxxodur two-component systems based on epoxy resins and curing agents. With these systems production of large rotor blades can be significantly accelerated thanks to a new curing agent. To assure that the forms for blades are filled completely and rapidly, the BASF systems react slowly initially. Subsequent heat application speeds the curing action and releases the form for production of the next blade more quickly. Consequently cycle times for the manufacture of rotor blades can be reduced by up to 30%, raising productivity accordingly. Because the new systems are processed additionally in a broader temperature range than conventional products, the production process becomes more flexible. Relius coating systems for reconditioning wind turbines As one of the world’s leading suppliers of rotor blade coatings for wind turbines, BASF is marketing high-quality solutions under the Relius brand. The coatings benefit from economies, high weather resistance and excellent elongation at break properties. The company has introduced an innovative, highly elastic repair system that in many cases will avoid a costly exchange of blades. The WindCoat Finish and WindCoat Protector SA coatings represent further developments of the established Relius line. WindCoat Finish is a matt final coat which can be applied manually or automatically without problems even if thicker coats are specified. Based on polyurethane, the WindCoat Protector spray coating adheres excellently without the use of solvents. It provides excellent adhesion to epoxy laminates and PUR Gelcoats. For years the Relius Rotor Blade System has served as a coating delivering durable protection for wind turbines. Relius products, especially suited for processing on glass fiber surfaces of rotor blades, include Gelcoat protective coatings, fillers, edge protection and top coats. The two-component coatings based on polyurethane are supplied low in solvents or solvent-free and conform to current VOC guidelines. Whether applied by roller, spray gun, manual or automatic methods, Relius coatings can be used in all manufacturing processes, including wet lamination, on prepreg laminates and in the infusion process. BASF’s strengths, ranging from solution-oriented consultations and individualized technical service to training attendant personnel, augment the advantages available from Relius brand products. Relius coatings for wind turbines have proven their worth for more than 15 years. High-performance plastic for epoxy resin composites available as micro-powder Recently the plastics divisions of BASF launched a high-temperature resistant Ultrason® thermoplastic E 2020 P SR, not only in the form of flakes but also micronized – thus as a powder. Due to its higher share of hydroxyl end groups the special version of the polyethersulfone (PES) is highly compatible with high-performance epoxy resins and has long proven itself in applications as an impact modifier. Sophisticated composites based on high-temperature resistant epoxy resins are used in airplanes and racing cars but stay very brittle unless modified with such heat-resistant impact modifiers. In its new powder form, it is more simply incorporated in the resin system. No longer does it have to be solubilized in a solvent which subsequently has to be removed. This saves customers time and money. The new micro-powder is immediately available in commercial quantities. New epoxy resin system with Germanischer Lloyd approval Sika Deutschland GmbH has introduced a new composite resin system, Biresin® CR83, into the composites market, approved by Germanischer Lloyd for use in wind turbines and also suitable for marine and industrial applications. The new resin system is particularly suitable for the resin infusion process, due to its low viscosity, good wetting characteristics and variable pot life. It has a very low tendency to crystallise which makes it very suitable for applications where storage in controlled temperature conditions is difficult. The low viscosity (155-170 mPa.s) and good wetting properties allow for very fast infusion with high quality impregnation. In recent trials Biresin CR83 infused the fibre lay-up in half the time of a typical, competitive infusion system and still gave 100% wet out of the fibres. This can reduce overall production cycle time and costs. It has 3 hardeners of different reactivity which allow the potlife to be varied at will. All hardeners are used in the same ratio and give excellent mechanical properties with a glass transition temperature = 80 °C. Wind energy is continuing its unbroken global success story. At the end of 2008, the World Wind Energy Association (WWEA) reported that wind energy plants with a total capacity of 120 gigawatts (GW) were installed worldwide. This represents a growth rate of almost 30% over the previous year. These plants supplied about 1.5% of global electric power consumption. The WWEA also estimates that by 2020 wind energy could supply at least 12% of the global demand for electric power. Moreover, advances in technology are expected to reduce the costs even further by then, adding economic competitiveness to the ecological benefits. Wind power as part of a mix with other energy sources will then make a sustainable contribution to energy supply across the world.