Press Releases 2014

A new world record for the direct conversion of sunlight into electricity has been established. The multi-junction solar cell converts 46% of the solar light into electrical energy and was developed by Soitec and CEA-Leti, France, together with the Fraunhofer Institute for Solar Energy Systems ISE, Germany. Multi-junction cells are used in concentrator photovoltaic (CPV) systems to produce low-cost electricity in photovoltaic power plants, in regions with a large amount of direct solar radiation. It is the cooperation’s second world record within one year, after the one previously announced in September 2013, and clearly demonstrates the strong competitiveness of the European photovoltaic research and industry. Multi-junction solar cells are based on a selection of III-V compound semiconductor materials. The world record cell is a four-junction cell, and each of its sub-cells converts precisely one quarter of the incoming photons in the wavelength range between 300 and 1750 nm into electricity. When applied in concentrator PV, a very small cell is used with a Fresnel lens, which concentrates the sunlight onto the cell. The new record efficiency was measured at a concentration of 508 suns and has been confirmed by the Japanese AIST (National Institute of Advanced Industrial Science and Technology), one of the leading centers for independent verification of solar cell performance results under standard testing conditions.

On October 23-24, 2014, representatives from industry and research will convene at Freiburg’s Fraunhofer Institute for Solar Energy Systems ISE to discuss new findings and applications in membrane distillation at the invitation of DME e.V., the German Seawater Desalination Association. The English-language conference is aimed at specialists and other interested individuals who wish to expand their knowledge and forge new contacts.

Together with industrial partners MERCK, HERAEUS and ASYS, researchers from the Fraunhofer Institute for Solar Energy Systems ISE have developed innovative new materials and contactless techniques for applying ultrafine, homogeneous contact fingers to solar cells. This ‘dispensing’ technology can be easily integrated into conventional silicon solar cell production lines where it replaces screen printing as the method of applying front side metallization: Consequently material usage is reduced, contact fingers are thinner and more of the semiconductor surface area is exposed to sunlight, which results in increased current collection and relative improvements in efficiency of around two percent. The new technology can also be used to optimize further production steps in solar cell manufacture.

In the joint European project “SCOOP” (Solar COllectors Made Of Polymers), a consortium, led by the Fraunhofer Institute for Solar Energy Systems ISE, has developed polymeric solar collectors that combine functionality, cost efficiency and aesthetics. The solar demonstration system of the project partner Aventa meets over 60 percent of the hot water and space heating demand for the 34 terraced houses, which are built to passive house standards. The new heating system was presented to the public in October 2014.

The calibration laboratory of the Fraunhofer Institute for Solar Energy Systems ISE has optimized its precision measurements even further. After performing comprehensive analyses, “CalLab PV Modules” was able to improve its measurement precision of PV module performance tests to 1.6 percent. A round robin event carried out among the internationally leading calibration laboratories (NREL in USA, AIST in Japan and JRC in Italy) confirmed the exceptional reproducibility of the measurements. Thus, Fraunhofer ISE once again strengthens its technological lead in the precision of electrical performance measurements of PV modules.

Since 1989 the European Commission has awarded the Becquerel Prize to distinguish outstanding merits in photovoltaics. This year the prize was awarded to Dr. Stefan Glunz, division director of “Solar Cells – Development and Characterization” at the Fraunhofer Institute for Solar Energy Systems ISE. The prize committee honors Stefan Glunz for his excellent pioneering work in the area of high efficiency silicon solar cells and his contribution to the worldwide success of photovoltaic electricity generation. The prize was presented on September 22, 2014 at the European PV Solar Energy Conference (EU PV-SEC) in Amsterdam.

In terms of sustainability, the City of Freiburg in Breisgau holds a leading role internationally. Also within Freiburg’s research scene, sustainability topics form a connective link between the research at the five local Fraunhofer institutes, with over 2000 employees, and between their work with the University of Freiburg, with whom they cooperate. Sustainability in Freiburg involves both the sciences and social sciences and emphasizes that the transformation to a sustainable lifestyle not only requires technological solutions but also public acceptance and suitable legal and economic boundary conditions.

PV systems in Germany are regularly generating higher yields than expected. An investigation by Fraunhofer ISE links these higher yields to an upward trend in solar radiation, pointing out that the current radiation level in Germany is considerably higher than the average values of the last 30 years. As these average values have generally been used in yield predictions up to now, actual PV system yields are exceeding their forecasts by approximately five percent, making them more cost-effective than anticipated. To take this effect into account, Freiburg researchers have adapted their quality assurance services for PV systems and are now basing their yield predictions on solar radiation data from the last ten years.

Under the leadership of the Fraunhofer Institute for Solar Energy Systems ISE, an interdisciplinary team is investigating how the transition to an energy system based on renewables finds durable acceptance among the German population. In addition to Fraunhofer ISE, the partners involved are the Fraunhofer Institute for Systems and Innovation Research ISI, the Center for Interdisciplinary Risk and Innovation Studies ZIRIUS at the University Stuttgart and the Institute for Political Science at the University of Münster (WWU). Public utilities and other partners with practical experience in the field supplement the team. The project called “KomMA-P | Strengthening the Acceptance of the Energy Transformation” is supported by the German Federal Ministry for Education and Research (BMBF). First results show that there is a large degree of acceptance for the energy transformation within the German population.

The Fraunhofer Institute for Solar Energy Systems ISE has been successfully developing concentrator photovoltaic (CPV) technology for many years. In this technology Fresnel lenses are used to bundle sunlight and focus it onto miniature, highly efficient solar cells. The FLATCON® module technology originates from Fraunhofer ISE and is continually under further development at the Institute. Now with their newest CPV module technology, the Freiburg researchers announce a world record module efficiency of 36.7 %, achieved by adapting the concentrating lens to a new solar cell structure. The high module efficiency was measured under Concentrator Standard Testing Conditions, or CSTC, and marks the best value ever achieved for a photovoltaic module.