Tuesday, 10 November 2015
The new metallic air receiver "MetRec" is the result of a cooperation between the DLR Institute of Solar Research and the Continental Corporation, department Fuel & Exhaust Management, which specialized mainly on exhaust technologies. MetRec is based on the concept of volumetric receivers which are already used in commercial power plants. As a key component of solar tower power plants, the new receiver type can significantly improve the performance and efficiency of the systems.
Solar thermal power plants will make a significant contribution to the global energy transition in the future. Commercial solar tower plants already generate electricity and heat for a vast number of households and industrial companies around the world. In order to maintain competitiveness in the long term, research and industry pursue the aim of reducing the cost of electricity from solar thermal power plants continuously. The diversity of different levels, on which the researchers are looking for solutions for this purpose, is now shown by the success of this at first glance unusual appearing cooperation.
The project was funded by the European Union and the state of North Rhine-Westphalia in the framework of the European Regional Development Fund.
Volumetric air receivers have been explored for a long time in solar thermal power plants and also recently transferred in the industry. Attached on a tower, they absorb solar radiation reflected and concentrated from mirrors. The generated heat can operate a turbine and thus generate electricity, or be used directly as process heat for industry. The storability of heat ideally allows electricity production 24 hours a day. Previously air receivers consisted of ceramic materials, which had a higher reliability compared to other materials. The two partners DLR and Continental have now succeeded with MetRec to manufacture a receiver of razor-thin, corrugated, and in the end wound high temperature steel foils which permanently withstand temperature loads of more than 900 degrees Celsius and briefly up to 1,100 degrees Celsius.
The actual focus of the business unit at Continental lies in the area of catalyst and filter technology for exhaust after-treatment of motor vehicle engines. The know-how of Continental as one of the leading companies in this area enabled the production of receiver foils with particularly fine structures, whereby the heat transfer to the air can be improved. 54 individual modules of the new MetRec receivers, combined to a total area of 1.1 m², were tested by DLR in June this year on the research level of the experimental solar power plant in Jülich and increased the conversion efficiency of solar radiation to heat by five to ten percent compared to formerly used ceramic materials. At the same time an increase of building costs is not expected by the use of high temperature steel foil instead of ceramic materials, thus a higher power output for the same construction cost becomes possible.
In order to realize the launch of this promising technology Continental and DLR currently communicate with project developers and power plant manufacturers. Thus together with several partners a first solar power plant with MetRec receiver technology shall be realized.