Green energy

30. Nov 2021 | Renewable energy

Protecting the climate also means promoting environmentally compatible energy production and making the energy supply as efficient as possible. The sun and wind already provide large amounts of environmentally friendly energy for industry and households in Germany. And this is important if we want to achieve the ambitious climate protection goals set in Paris in 2015. Good to see that polymer materials promise more efficiency in the generation of renewable energies.

On and offshore wind power

In wind energy, ever larger rotor blades produce ever more power. This is made possible by extremely tensile plastic composites that can withstand even top speeds of up to 300 kilometres per hour and neither burst nor bend. While today’s rotor blades are already 140 to 160 m long and reach a rated output of 10,000 kW, experts expect this to increase to over 250 m or 20,000 kW in the coming years.

Covestro, Goldwind und LZ Blades entwickeln das weltweit erste 64,2 Meter lange PU-Windrotorblatt

Wind turbines on the high seas in particular are exposed to extreme environmental influences and must be designed to be particularly resistant. Special polyurethane systems are therefore the method of choice in various parts of a wind turbine, such as the rotor blades. Polyurethane resins improve the mechanical properties there and reduce the costs of the turbine compared to alternative solutions.

Ecological benefits thanks to research

A German plastics producer has now also succeeded in developing CO₂-based polyurethane for dampers and kink protection of a wind turbine, among other things. The “climate gas” thus becomes a raw material for the German and global energy transition. Another exciting step: it is now possible to produce rotor blades entirely from polyurethane instead of the conventional sandwich construction including a mix of materials. Possibly an upcoming advantage with regard to the subsequent recyclability of rotor blades at the end of their useful life.

Materials incredibly versatile

Silicone rubbers are other important helpers in generating clean electricity. In wind turbines, they seal housing parts, insulate electrical cables, protect sensitive electronics from vibrations, moisture and dust – and thus ensure that control components do not overheat. Silicones are also useful in photovoltaics. The frame construction of solar modules and many system components are sealed and fixed with high-performance sealants and potting compounds made of silicone. The material is very easy to process, defies wind and weather and is just as elastic and flexible in tropical heat as it is in freezing cold.

Solar power thanks to wafer-thin film

Speaking of photovoltaics: Photovoltaic cells printed on thin plastic carrier films make it possible to generate electricity exactly where it is needed. This solar power technology is not only efficient and durable, but also particularly flexible and adaptable. Thus, energy-producing house façades and roofs that light up at night could soon be seen everywhere in the city. Smartphones, tablets and cars could be covered with thin, electricity-generating foil to cover their energy needs. At the German Pavilion at EXPO 2015 in Milan, this technology has already been used with success. (Photo).

Landschaftsebene mit Solarttrees

Organic photovoltaics on buildings

The integration of renewable energies in buildings has long since become increasingly mandatory worldwide. To meet this requirement, manufacturers are relying on an exciting combination of printed organic photovoltaics (OPV) and ETFE films; the latter already enable wide-span, lightweight constructions in many public buildings such as shopping malls, airports or stadiums, through which ample daylight can penetrate.

However, conventional photovoltaic elements were hardly compatible with these established membrane constructions, so resourceful inventors brought OPV into play. In combination with ETFE films, this makes possible lightweight, aesthetically pleasing façades that can store cold and heat and release it as needed – helping to reduce energy demand in buildings.