In harmony with nature – the first car wash with intelligent rainwater management and a solar green roof

In harmony with nature – the first car wash with intelligent rainwater management and a solar green roof

An unusual car wash has been available in Ochtrup for some time now: The wi-wash car wash on Hauptstraße is equipped with a greened hall roof, offering many advantages.

An unusual car wash has been available in Ochtrup for some time now: the wi-wash car wash on Hauptstraße is not only impressive because of its technically sophisticated and high-performance equipment, which offers everything needed for the perfect washing and care of vehicles. In harmony with nature, the entire hall roof has also been greened and equipped with a solar system. This has many advantages.

The car wash, which belongs to the Wischemann Group, is probably the only car wash whose roof is completely greened. The idea came from Optigrün international AG, the market leader in green roofs and a long-standing customer service. For many years, Wischemann has been producing a large part of the drainage panels developed by Optigrün for their green roof systems. It was a logical consequence for Ingo Wischemann, builder and owner of the Wischemann Group, the most important plastics specialist for innovative thermoformed parts and thermoforming processes in Europe, to use the advantages of green roofs for the washing park and thus to build sustainably at the same time.

Intelligent rainwater management

The greening of the hall roof was carried out using the water-retention roof system developed by Optigrün. The system for different types of green roofs can retain large amounts of rainwater – in this case up to 75,000 litres. The WRB 80F water-retention boxes used here are 80 mm high plastic hollow bodies that are used in the drainage level. With the help of the Optigrün Smart Flow Control, an intelligently server-controlled throttle, a defined outflow of the water as well as a permanent water accumulation in the retention boxes is determined. In this way, the retention area is divided into a temporary and a permanent water reservoir.

The stored water is transported via capillary bridges into the fleece that lies on top of the retention boxes. The water is distributed over the entire surface via the fleece and keeps the overlying substrate layer moist. Thus, the precipitation water is available to the vegetation for evaporation or can also be used in the washing park. The temporary storage tank in the retention area is emptied with a long delay when needed – for example, during a predicted rain event – via the throttle operated by an intelligent control system. In this way, low discharge restrictions can be adhered to and protection against flooding is provided even during rain events with large annualities. 

Advantages of a green roof

A green roof not only binds CO2 and particulate matter, but also acts as insulation. In winter it protects against the cold and in summer the building and the surrounding air do not get as hot as with ungreened buildings. In addition, a green roof protects the roof cladding from damage caused by the effects of heat/cold and hail.

Evaporation via the drought-resistant vegetation contributes to maintaining the natural water balance and at the same time lowers the ambient temperature. In addition, the sewer system is relieved, drains can be reduced, sewer pipes can be made smaller and stormwater overflow basins can be saved. A retention green roof also has a positive effect on biodiversity and the microclimate. In addition, the green roof provides a habitat for flora and fauna.

Green electricity from the roof for the charging columns

In terms of sustainability, however, the construction of the car wash was not just about using rainwater. Rather, a photovoltaic system was also installed on the roof. The combination of green roof and photovoltaics does not represent a conflict of objectives but is the ideal symbiosis for a sustainable development.

Thus, the roof area of the car wash not only offers space for the expansion of renewable energies. Rather, the combination of green roof and solar roof increases the economic and ecological functionality of the building. This is because the efficiency of energy generation from solar modules decreases with increasing temperatures. The green roof, however, increases the efficiency because the temperature of the modules rises more slowly due to the evaporative cooling of the vegetation.

The electricity, which is generated in a resource-saving way, can be stored on site by six storage units so that it can be used as needed or fed into the electricity grid. For example, the temporarily stored electricity can be used by customers at the e-charging station while they are vacuuming. This is an innovative solution for solar green roofs.

The Optigrün-Solar WRB system used on the roof of the car wash is a load-bearing solar elevation that is fixed in place by the green roof structure to prevent wind suction. Thus, no penetration of the roof is necessary, which in turn avoids damage to the roof cladding. The Optigrün-System Solar WRB consists of an aluminium base plate on which the water retention box is placed. Brackets used as module supports are inserted and screwed into the supports of the base plate. The individual elements are connected with the help of quick-assembly module rails. The solar elevation is then ballasted with substrate.

The clear advantage of ballasted solar elevations is that the roof cladding does not have to be penetrated. Damage to the roof cladding and consequent repair work or leaks are thus ruled out.

For care and maintenance work, the Optigrün- Optisafe ALS, a rope-guided restraint system, was used as fall protection. Up to two people with their protective equipment can be suspended here at the same time.

The washing park in Ochtrup shows in an impressive way that with good planning and the right system the effects of climate change can be mitigated.

More details:

Owner: Wischemann Group

Planning: Dorin-Immo GmbH & Co. KG

Execution of Greenroof: Marcel Nadorf GmbH

Supply of solar green roof and planning support: Optigrün international AG.

© Optigrün international AG

© Optigrün international AG

© Optigrün international AG

© Optigrün international AG

Car Wash

Year: 2021

City: Ochtrup

Location: Germany



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