Solar and green are a good fit for a roof

Solar and green are a good fit for a roof

In today’s world, the sensible and extensive use of flat roofs is indispensable from a socio-ecological perspective and from the point of view of sustainability. For example, the greening or landscaping of flat roofs brings enormous benefits in many respects and can make a significant contribution to combating climate change. At the same time, from an ecological perspective, the promotion of renewable energies such as the use of PV panels is an important component of a future-oriented sustainable energy policy. With the right system, significant synergy effects are achieved when combining both.

Green roofs offer a wide range of benefits. They enhance thermal insulation and protect the waterproofing, they preserve biodiversity by offering a natural habitat for plants and animals and they retain stormwater which helps in heavy rain events. In addition, they can improve the microclimate by reducing the urban heat island effect, and they create important garden and recreational areas thus satisfying the human need for vibrant green surroundings. ZinCo does not only provide the right system for any sort of green and landscaped roof but with the ZinCo SolarVert® build-up system adds a significant new benefit: the integration of solar energy use into the green roof build-up.

Today’s solar systems are perfectly designed for minimum installation effort and maximum yield from operation. It is for this very reason that photovoltaic systems, in particular, are increasingly used in combination with green roofs, as the latter produce considerable synergy effects thanks to their superimposed load and low ambient temperature.

One important synergy effect shows at the construction stage. The ZinCo solar build-up consists of a protection and drainage layer, Solar Bases plates and Solar Base Frames. The Solar Base plates are covered with a prescribed amount of growing medium and the desired vegetation is then planted. The combined weight of the growing media and plants provides the calculated ballast required by the solar energy system to deal with wind loads. Thanks to this ballast principle, roof membrane penetrations that would normally be necessary for anchoring standard solar energy systems are not required. This principle provides an even load distribution and avoids point loads.

The lower ambient temperature of a green roof provides further synergy effects. While a gravel roof will heat up quickly in the middle of summer, vegetation will help to create a comparably moderate ambient temperature of only 30° to 35 °C. As the efficiency of PV modules decreases by up to 0.5 % for every Kelvin depending on the product used, a green roof demonstrably increases the yield from the system. With its SolarVert® system build-up and a wide range of related accessories, ZinCo provides a high level of flexibility and, as a result, an attractive solution for each solar energy project.

As a base layer the ZinCo SolarVert® system uses the drainage and water storage element Fixodrain® XD 20 with its pre-attached filter sheet. This is installed across the entire area allowing for the Solar Bases applied on top to be positioned as required in line with installer instructions. The Solar Base Frames supporting the solar panels are fitted next. They are followed by the system substrate “Sedum Carpet” and the appropriate Sedum vegetation providing the load required to protect the system against wind uplift. The height of the Solar Base frames creates enough distance between the substrate layer and the solar panels, providing the plants with enough sunlight and rainwater and enabling appropriate maintenance.

The “SolarVert” build-up has first been designed for the classical southern exposure with a maximal energy yield during the midday period. Meanwhile, ZinCo systems with an east-west orientation aiming at a more evenly distributed yield during the day and avoiding excessive power peaks are available as an option. In addition, their yield is greater given that a larger module area can be created.

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