Normal solar panels are unthinkable on listed buildings. The solution was found in Italy: they build solar tiles that look just like the terracotta ones. Pompeii Park installs the invisible collectors.
Terracotta bricks have been a feature of Mediterranean cities since the days of the Empire. The idea that these historic roofs are spoiled by black solar panels is hard for preservationists to bear. These roofs are particularly suitable for this. For one thing, there are far more hours of sunshine around the Mediterranean than in Denmark, for example, and then the terracotta roofs have only a slight incline, so a panel like this can catch the sun for many hours a day.
Pompeii installs solar tiles
The Pompeii Historical Park has now solved this problem. The Cecere house is fed by solar energy – invisible, because the collectors resemble the terracotta roof tiles. “They look exactly like the terracotta tiles used by the Romans,” said Gabriel Breeding, director of the Pompeii Archaeological Park. “Pompeii” is an ancient city that is completely preserved in some places. Since we needed an extensive lighting system, we could either continue to use energy, leaving pylons and cables lying around and spoiling the landscape, or choose to respect it and to save millions of euros.”
These bricks are built by the small Italian family business Dyaqua. A polymer mass is applied above the actual photovoltaic cells, which is colored but which lets through the light components that the cells need. “We can also create the appearance of stone, wood, concrete and brick. Therefore, such a solution can be installed not only on roofs, but also on walls and floors,” says the company.
Properties like a real brick
At the moment this is still done by hand. The curved shape of the roof tiles and the coloring will have an effect on efficiency, but the advantage outweighs the disadvantage: entire old towns can be equipped with the coated solar panels without changing the historical impression. And that is a basic requirement in many countries in order to be able to install a solar system in a protected environment.
As part of the European “Pocityf” project, bricks of this type are being installed at various locations in order to be able to show demo systems to interested customers. These include buildings in Split, Croatia and Evora, Portugal and Alkmaar in the Netherlands.
The advantages are particularly evident in Evora. The city is not flat. You always look at the roofs of the other houses, so it is not possible to hide conventional panels from view.
The sun bricks not only look different, they also follow a different construction method than the well-known panels. They are foreign bodies on the roof and are mounted above the actual roof with a support frame. A roof above the roof, so to speak.
The solar bricks, on the other hand, have the same properties as real bricks. So old can be exchanged for new. They themselves form the roof surface and are fully walkable. No duplicate construction is needed. In Pompeii people are satisfied with the invisible photovoltaic system and will use it in all buildings in the future.