At Grazerfeld, the real innovation of the solar folding roof is not on the roof itself, but in its support structure. To span the circular tanks of the wastewater treatment plant in Wildon, dhp Technology developed a new axis solution that has never before been implemented in this form.
At the heart of the solution is the so-called Axis G. Its design enables a new approach to load transfer, creating the structural basis for spanning large areas of the existing infrastructure with the solar folding roof – without restricting the primary operation of the wastewater treatment plant.
Wastewater treatment plants offer large areas for solar power generation, but they also place high demands on structural design. Tanks, traffic routes, pipelines and other plant components must remain accessible, while ongoing operations must not be disrupted by the additional solar infrastructure.
At Grazerfeld, the geometry of the circular tanks presented a particular challenge for the structural design. Under these conditions, a conventional axis design could not be implemented effectively.
The answer was not to adapt the existing infrastructure to the solar folding roof. Instead, the support structure was adapted to the infrastructure.
For Grazerfeld, dhp Technology therefore developed a project-specific design. Axis G transfers loads via individual structural elements supported by compression struts. Inclined tension cables or tension rods transfer the resulting forces into the ground. Where required, the anchor points are supplemented by small foundations.
The result is a support structure designed specifically around the complex geometry of the wastewater treatment plant while meeting the structural requirements of the solar folding roof.
The design takes into account existing tank walls, external foundations, different connection conditions and the plant’s operational requirements. This makes it possible to use areas for solar power generation that would be difficult or impossible to access with conventional support structures.
Grazerfeld demonstrates another key strength of the solar folding roof: the system is not tied to a rigid grid. The support structure, spans and axes can be adapted to the existing infrastructure.
This flexibility is particularly important at wastewater treatment plants. The areas suitable for photovoltaics are already being used for technical processes. To unlock them for additional solar power generation, the solar infrastructure must adapt to the existing facility – not the other way around.
With the newly developed axis solution at Grazerfeld, dhp Technology is taking this principle a step further. The special design makes it possible to span the circular tanks and expands the potential applications of the solar folding roof on complex infrastructure sites.
The support structure will carry a solar folding roof with an installable capacity of approximately 1.85 MWp and a projected average annual solar power yield of around 1,873 MWh.
The project therefore combines two levels of innovation: the dual use of an already intensively used area for renewable energy generation and a newly developed support structure that makes this additional use possible in the first place.
Grazerfeld demonstrates what can be achieved when photovoltaics are not planned independently of existing infrastructure, but are structurally designed around it.