Solar roofing tiles

Roofing tiles with built-in solar panels

Solar panels cannot be installed everywhere: sometimes the house’s roof is too irregularly shaped, it may be a listed building or the owners may reject the idea for aesthetic reasons. The company paXos from Cologne has developed an innovative solution for this problem in the form of solar roofing tiles. They combine three functions: providing roof covering and producing electricity and warm water. A patented snap-in system makes it possible to lay the roofing tiles quickly and easily. Using this new approach will allow further expansion of renewable energy, particularly in urban areas.

65 per cent of the electricity consumed is to be generated by renewable energy by 2030: that is the German government’s target. In order to make a successful contribution to this target, North Rhine-Westphalia needs to increase its annual output from solar and wind power plants by around 800 MW each, according to a study by the state association for renewable energy. With its solar roofing tiles, paXos is now providing new potential for the expansion of renewable energy. The solar roofing tiles make it possible to exploit those roofs which are unsuitable for conventional solar panels for visual, regulatory or technical reasons.

Engine for progress:

  • Exploits new potential for using solar energy
  • Innovative snap-in system allows easy installation
  • Suitable for both new buildings and renovation of older buildings
  • High level of PV efficiency achieved by removing the heat
  • Jobs will be created when mass production starts

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Photo: paXos

The first sample roof on show – soon a whole show house will be built with solar roofing tiles as a test site.

Increase in the performance of solar cells

Solar cells, which are installed in photovoltaic systems, lose output when they become hot. They achieve their best output at a temperature of 25 degrees; if they become hotter than this, they lose about 0.5 per cent of their output efficiency per degree Celsius. Solar roofing tiles use the accruing heat and transport it away. The solar cell itself therefore remains cooler and can generate more electrical power, particularly in midsummer. The temperature in the attic as a whole is thereby also reduced. In winter the solar fluid melts the snow and allows solar power to be generated even on colder days. Overall, the efficiency of the solar cells increases – making them competitive on the market.

Flexible to use

The solar roofing tiles can be adjusted to suit the length of the battens to which the tiles are attached. This is particularly important because the distance between the battens is not always identical. The system can be used both in constructing new houses and in renovating older ones. The patented snap-in system ensures that the tiles are securely connected – both in terms of the flow of electricity between the individual tiles and the circulation of the heat transfer fluid. Thanks to its rapid mounting and installation, the system remains competitive. The overall system also includes a patented down pipe in which the cables are bundled together and run down the outside of the building out of sight – a further advantage in terms of the visual appearance of the building.

Mass production from 2019

Mass production of the solar roofing tiles is planned to start at the end of 2019: paXos and RheinEnergie have signed a so-called patent and technology licence agreement to jointly bring the solar roofing tiles to the production stage. They initially intend to manufacture around 750,000 tiles per year and then, within a period of three years, to increase production to at least 3,000,000 tiles per year – thereby also creating new jobs. In addition, a show house with solar roofing tiles is currently being built for testing purposes on RheinEnergie‘s premises. Cologne University of Applied Sciences is also providing important scientific evaluations.

Foto: paXos

“When it takes off, it will do so on a huge scale. A large number of house owners are interested in renewable energy, but until now they have not found a satisfactory solution in this field. At the same time, the demand for energy is continuing to rise, in part as a result of electromobility. The solar roofing tile could potentially revolutionise the market.”

Peter Hakenberg, Managing Director of paXos

Partners and sponsors

  • RheinEnergie AG
  • Technische Hochschule Köln
  • paXos Consulting & Engineering GmbH & Co. KG