Green roof and PV tubes

The combination of green roofs with tubular photovoltaic modules was awarded the GaLaBau Innovation Medal 2022. This innovative combination allows for lightweight constructions ranging from extensive green roofs to roof gardens.

Also existing green roofs which cannot be equipped with the traditional photovoltaic panels for structural reasons, may be retrofitted with this solution.

The innovative tube technology provides excellent growth conditions for the plants thanks to the permeability of daylight and water. On the other hand the PV plant benefits from the cooler ambient temperature caused by the vegetation.

ZinCo und its partner TubeSolar AG see further benefits concerning a continuous generation of solar power throughout the day.

In principle, the aim of generating solar power consistently throughout the day is desirable. It requires less storage capacity and contributes to grid relief. Solar panel modules too are increasingly assembled in an East-West direction – either at a slight angle or more recently vertical with bi-facial PV modules. This results in two peaks during the day, in the morning and the evening. The PV tubes can do better than that: they continually produce solar power because at all times of the day the sun rays hit the relevant tube section at a right angle.

Besides, the lightweight PV tubes provide considerably less wind attack area if they are horizontal, and the solar base frame can have smaller dimensions. This allows for a cost-effective lightweight design. As always with ZinCo products, the solar base frames do not require roof penetration as they are held firmly in place by the superimposed substrate layer of the green roof.

A win-win situation

The solar energy system benefits from the green roof due to the cooler ambient temperature and the resulting measurable increased yield.
Likewise, the green roof benefits from the water and daylight permeability of the tubular design. The partial shading of vegetation actually has some advantages, above all in dry regions. Evaporation is reduced (water consumption) and the vegetation is protected from too intense sun

Wide range

Industry and business offer the greatest market potential here, however, this combination is also valuable on urban and private buildings that have a flat roof with an extensive green roof for maximum solar power generation. In addition, the range of applications is expanding to include the field of intensive green roofs because in this case, the PV tubes can be mounted at any height and can even be used as a canopy over a patio. This was the specific variant that the university team from Biberach used when participating in the Solar Decathlon Europe SDE 21-22 in Wuppertal. Their building was adorned with a fabulous pergola made of PV tubes over a ZinCo Stormwater Management Roof.

Innovative thinking

Architects and building planners can be endlessly creative. They have an enormous selection to hand in this field, where they make use of and combine today’s solar and green roof technology with their maximised ecosystem services – without competing for space. Photovoltaic, storm management, patio areas, biodiversity and urban farming go hand in hand with PV tube modules, even in smart mode.

Author: Dipl.-Wirt.-Ing. (FH) Sandra Schöll, Press Office ZinCo GmbH