Modular Energy
Our power plant site in Kehl, Germany, shows how we’re expanding our energy mix at Koehler. With a photovoltaic system on the roof of its biomass storage building, the site has been producing its own solar power since 2025: a pilot project that hints at what is to come elsewhere.
Since 2022, the challenges in the energy industry, together with steep increases in electricity prices, have led to countless questions. A key one: How can you save electricity – or even generate it yourself to cover your own use? The Koehler Renewable Energy Technology and Operations Team did not look to paper for the answer, but rather to the roofs of our power plant sites. Project Manager Leon Bechmann explains: “The idea was to install photovoltaic systems at our sites in order to lower our energy costs while simultaneously contributing to achieving our sustainability objectives.”
The Technology and Operations Team supervises Koehler Renewable Energy’s power plant sites, and started by checking where using PV systems would be possible and cost-effective. It quickly became apparent that our Kehl site had enormous potential: a large biomass storage building with a suitable roof and proximity to our headquarters – perfect for a pilot project.
PV modules on the roof convert sunlight into electricity.
Technology That Fits Right In
However: The building was from 2002, and there had been no plans to accommodate a PV system originally. This meant that structural analyses had to be found, reviewed, and re-analyzed. Ultimately, the team decided to use a particularly lightweight rail system that would distribute the load evenly. And regulations also played a role: Clearances at the edge of the roof had to be maintained due to wind and snow loads. Meanwhile, the TSO checked whether the system would be compatible with the local grid – a process that took additional time.
The power flows into our system, so we need less energy from the public grid.
The power flows into our system, so we need less energy from the public grid.
Project Manager at
Koehler Renewable Energy
A Collaborative Project Through and Through
In January 2025, after the project development stage was done and only four months after the team had sent in the contract, the PV system went online. Bechmann was impressed by how quickly the whole thing was installed and put together. “I was on the roof one morning and there was barely anything there. Four hours later, bam! Just endless modules,” he recounts.
For the actual planning and construction, Koehler Renewable Energy worked with WiSo Solar, from the German city of Wiesbaden, after a Germany-wide request for bids in which the team looked for relevant certifications and experience in the industrial sector. “There’s a huge difference between installing small residential solar and large-scale projects,” Bechmann says. The work went smoothly and continued beyond the project both in terms of PV system maintenance and for potential subsequent projects.
Energy at the Kehl Site: Two biomass combined heat and power plants supply power and process steam for paper production. The PV system supplies additional self-generated energy.
Electrifying Success
The final system comprises 607 PV modules, and the power it generates is used directly on site. With a peak output of around 267 KW, it covers around 9% of the electricity that the power plant site normally purchases from third parties. “The power flows into our system, so we need less energy from the public grid,” Bechmann explains.
The results have surpassed expectations: The system will pay for itself faster than planned and is making an important contribution to our energy mix. “It’s a great feeling when a project exceeds your own estimates,” Bechmann proudly adds.
With PV on the roof and biomass inside, the storage building serves a double purpose at our power plant site.
A Pilot Project With a Future
PV systems continue to be a relatively small building block in our company’s energy mix, but not for long. In fact, the system in Kehl was intended as a pilot project for our other power plant sites. Bechmann considers the project to be a special milestone.
He had originally signed up to be in charge out of an interest in new technologies. “I love to tackle stuff that I didn’t know about before,” he says. And Kehl shows how this motivation turned into concrete results: Solar power that now flows directly into our production operations.
A Brief Chat:
Birgit Hagebölling,
Corporate Director Technology & Operations at
Koehler Renewable Energy
What kind of role does sustainable energy play in the Koehler Group’s strategy?
Sustainability plays a vital role in the Koehler Group’s strategy. The Koehler Group has made a promise: By 2030, we want to generate, on an annual basis, more energy from renewable sources than is needed for our paper production operations. This is a promise we’re delivering on with the “A Visionary Approach to Climate Action” Area of Action of our sustainability strategy.
Is there potential for more energy efficiency somewhere?
Koehler Renewable Energy is pursuing a variety of projects in the area of energy efficiency that we’re supporting with feasibility and potential studies. We’re finding that it’s more important than ever to handle resources sustainably, promote circular economy practices, and improve efficiency. Improvement processes are our steadfast companion there.
