Sustainable HQ Achieves Energy Neutral Future

Sempergreen HQ to Operate Entirely on Solar Energy!

Sempergreen’s headquarters in Odijk, Netherlands faced a challenge: despite having a large number of solar panels on the flat roof, there remained a shortfall of 10,000 kWh per year to fully cover the office’s energy consumption with renewable solar energy. The question was clear: how could this energy gap be closed without exceeding the roof’s load capacity? The innovative Over Easy Solar system provided the solution – enabling Sempergreen HQ to operate entirely on solar energy!

How to generate more energy without exceeding maximum roof load bearing capacity?

The challenge was that the roof of Sempergreen HQ already had a green roof weighing 90 lbs/ft². The roof’s load-bearing capacity is limited to 132 lbs/ft², leaving no room to install additional solar panels without risking overload. So it was essential to find a solution that on the one hand allowed for the additional energy generation and on the other would not exceed the maximum roof load.

Solar panels while preserving the green roof

The aim was to maximize solar energy production without compromising the existing green cover. A solution was needed that both retained the benefits of the green roof and could provide the additional solar energy needed. And all this had to be accomplished with minimal impact on the existing green roof.

Over Easy Solar solution for lightweight green roof

At Sempergreen HQ, this challenge was solved with partners by using the Over Easy Solar system. This innovative system consists of lightweight, vertical PV units that weigh only 24 lbs/ft². This was well within the load-bearing capacity of the roof, providing the ideal solution. In close cooperation with installation partner SamenStromen, responsible for installing the solar panels and optimizing the system, the solution was implemented seamlessly. Although a small portion of the green cover had to be removed to accommodate real-time monitoring of the yield, all the Sedum roof’s ecological benefits remained fully intact.

“I find working with Sempergreen to be an absolute pleasure”

Richard Duckers | OTG.Energy part of Samenstromen

Green Effect:
30% more energy yield with Over Easy Solar system

One of the most striking aspects of this project is the use of the lightweight Over Easy Solar system, which in combination with the green roof provides a 30% increase in energy generation through the so-called Green Effect. The plants reflect sunlight to the solar panels (albedo effect) and provide cooling on the roof. Since the panels are vertically mounted, a large part of the green roof remains uncovered. This vertical design allows many more sun rays to hit the green surface, which then reflect to the solar panels. This significantly increases the amount of available light radiation on the panels and thus the energy output of this PV solution. Combining green roofs with solar panels in this way is a unique and highly effective approach, merging sustainability with high-performance energy production. In addition, installation is quick and easy, without the risk of overloading the roof. The Plug & Play units are 10 times faster to install than conventional Solar systems.

At Sempergreen, we are committed to integrating innovative and sustainable solutions into all our projects.

Aldo Tognini | CEO Sempergreen

A green building powered by renewable energy

Thanks to the installation of the lightweight solar panels, Sempergreen HQ now generates 9,360 kWh per year, virtually equivalent to the office’s entire energy consumption. The green roof remains intact, so the office now enjoys the benefits of both sustainable energy generation and a healthy, green building. The integration of Over Easy Solar with the Sempergreen green roof completely resolved the energy challenge.

How does installer OTG Energy reflect on this pioneering project?

Richard Duckers from OTG Energy was closely involved in the installation of the Solar Green Roof with Over Easy Solar. How does he look back on this innovative project?

Richard: “The installation of the Over Easy units is exceptionally simple and requires no ballast, making them ideal for roofs with low load-bearing capacity. Moreover, the installation process is more than twice as fast compared to conventional solar energy solutions!”

“What truly makes this system innovative is not just the solar panel technology itself, but the synergy with a thriving green roof. Thanks to the vertical setup, the Sedum receives enough sunlight and water to flourish while the roof simultaneously generates solar energy. Additionally, roof space is used to its full potential: because of the vertical panel design, there is no need to leave clearance near the roof edges, increasing the usable surface area. Maintenance is also easy—you can simply walk between the panels.”

“To further investigate the benefits of Over Easy Solar on a green roof, we have set up a test installation with both Over Easy units on Sedum and on bitumen roofing. This allows us to measure the differences in energy generation and the impact of the albedo effect. The results show that the reflective capacity of greenery is significantly higher than that of black bitumen. Combined with the cooling effect of the plants, the green roof has an extremely positive impact on the performance of the solar panels.“

Explore

Solargreen Roofs

Explore

Green roofs

Start your green project today

Ready to make a difference? At Sempergreen, we believe in building a greener future, one step at a time. Our innovative solutions are designed to help you decrease your footprint and contribute to a more sustainable world. Join us in replanting the planet!