- New PMMA specialty products for concentrated photovoltaics
- Outstanding optical properties combined with excellent weather resistance
Darmstadt – The Acrylic Polymers Business Line of Evonik Industries AG has presented its new product group PLEXIGLAS® Solar at the International Trade Fair for Plastics Processing, FAKUMA 2009 in Friedrichshafen.
Making optimal use of solar power is one of the great challenges for future energy supply. Concentrated photovoltaics (CPV) is classed as one of the most efficient methods for generating electrical current directly from sunlight. In this method, lenses with microstructures (Fresnel lenses, for instance) are placed in front of a highly efficient solar cell. The effect achieved in this way is that the sunlight that would otherwise be spread over several square meters is concentrated on a fraction of that area (up to a thousandth) and is then converted to power by highly efficient solar cells.
There are four reasons in favor of using PLEXIGLAS® as a material for solar power generation. It has outstanding optical properties and excellent UV and weather resistance, can be very precisely processed and shows extremely high impact strength despite its low weight. With the new PLEXIGLAS® Solar product group, Evonik offers a complete range of molding compounds and solid sheets for all demanding applications in the field of lens manufacture for concentrated photovoltaics. The PLEXIGLAS® Solar product portfolio is rounded off by the ACRIFIX® Solar adhesives concept. This UV-curable reactive resin system is perfectly adjusted to the PLEXIGLAS® Solar products.
The light that impinges on a lens is to be focused onto a small solar cell with maximum efficiency and without losing part of this energy on the way, due to absorption, for example. That makes stringent demands on the material and its optical properties. PLEXIGLAS® has a low refractive index, a very high transmittance of more than 92 percent and high transparency. Besides this, PLEXIGLAS® always absorbs a very low proportion of radiation both in the visible and the UV range. A further point in its favor is its long service life. This is underlined by CPV systems that have been successfully operated with the trademark PMMA from Evonik for more than 15 years.
The advantage of Fresnel lenses for solar power generation lies in their fine structures. To manufacture these structures with precision, it takes equally precise molds and dies in injection molding and extrusion processes. The microstructures of the lenses can only be precisely replicated using a material with highly accurate mold surface reproduction. PLEXIGLAS® meets this requirement. What is more, PLEXIGLAS® is very robust. It is much more impact-resistant, yet lighter in weight than glass, and withstands even hard hailstones. PLEXIGLAS® has the greatest surface hardness and scratch resistance of all thermoplastics.
Evonik Industries is the creative industrial group from Germany which operates in three business areas: Chemicals, Energy and Real Estate. Evonik is a global leader in specialty chemicals, an expert in power generation from hard coal and renewable energies, and one of the largest private residential real estate companies in Germany. Our strengths are creativity, specialization, continuous self-renewal, and reliability. Evonik is active in over 100 countries around the world. In its fiscal year 2008 about 41,000 employees generated sales of about €15.9 billion and an operating profit (EBITDA) of about €2.2 billion.
In so far as forecasts or expectations are expressed in this press release or where our statements concern the future, these forecasts, expectations or statements may involve known or unknown risks and uncertainties. Actual results or developments may vary, depending on changes in the operating environment. Neither Evonik Industries AG nor its group companies assume an obligation to update the forecasts, expectations or statements contained in this release.