Manufacturing processes for solar thermal technology

© Fraunhofer ISE

Typical solar thermal absorbers are constructions made from absorber plate and pipe registers in meander or harp style. This manufacturing style was further developed for years and is automated to a significant extent today. The materials being used are copper and/or aluminum. The collectors available on the market show very good thermal efficiencies, are durable and reliable.

New manufacturing processes provide the potential to reduce costs and/or increase the efficiency of collectors. To achieve this, we develop, test and assess new absorber concepts together with our clients.

We focus on production processes that are often established in other branches and need to be adjusted to the requirements of solar absorber manufacture, as well as new materials like steel, polymers or ultra-high-performance concrete. Prototypes and small batches with spectrally selective coatings can be manufactured at Fraunhofer ISE, using our long-standing expertise in coating technologies.

The use of manufacturing processes like roll bonding, hydroforming or deep drawing changes the channel geometry: individually welded pipes are replaced by channels with flexible cross-section geometries and channel layouts. We use models and measurements to analyze the effects of these changes on the thermal efficiency and pressure loss. Our FracTherm® technique enables us to generate such nature-inspired channel structures on almost any surface.