Schiesser's solar strategy: Sustainable energy generation in everyday business

Published on: June 4, 2025 / Updated on: June 4, 2025 – Author: Konrad Wolfenstein

Underwear company Schiesser's solar strategy: Sustainable energy generation in everyday business – Image: Xpert.Digital

Schiesser increases sustainability with solar energy and district heating

Traditional brand Schiesser drives green innovations forward

The long-established underwear manufacturer Schiesser has consistently developed its sustainability strategy and now operates three photovoltaic systems at its Radolfzell site. These systems generate a combined total of over 1,100 megawatt hours of electricity annually, covering a significant portion of the company's energy needs. Furthermore, Schiesser has opted for the innovative district heating project "Zeller Wärme am Klärwerk" (Zeller Heat at the Wastewater Treatment Plant), which is scheduled to go into operation by the end of 2026. These measures are being implemented against the backdrop of new legal frameworks, particularly the Solar Peak Act, which came into force in March 2025 and brings about significant changes for photovoltaic system operators.

Schiesser's photovoltaic offensive

Schiesser's decision to increasingly rely on solar energy is part of the company's broader sustainability strategy. With three photovoltaic systems at one location, the company demonstrates how industrial roof surfaces can be optimally used for energy generation. This gradual expansion of solar capacity reflects a long-term and well-considered approach to renewable energy planning.

Andreas Lindemann, CEO of the Schiesser Group, emphasizes: “Sustainability has been part of SCHIESSER’s DNA since 1875. The various solar projects align very well with our corporate values.” This statement underscores that the current environmental protection measures are not merely short-term reactions to regulatory requirements, but rather a consistent continuation of traditional corporate values in a contemporary form.

Detailed analysis of the photovoltaic systems at Schiesser

First facility: Sales building (March 2020)

The first photovoltaic system was installed on the roof of the sales building in March 2020, marking the beginning of Schiesser's comprehensive solar strategy. With an area of over 600 square meters, this system played a key pioneering role, demonstrating the technical feasibility and economic viability of solar energy at the Radolfzell site. While the annual CO₂ savings of approximately 40 tons may seem moderate compared to subsequent installations, they formed the basis for scaling up solar activities.

Second facility: Shipping building (November 2021)

The second and, to date, largest photovoltaic system went into operation in November 2021 and significantly surpasses the first system in both area and output. Covering over 3,700 square meters, it occupies approximately two-thirds of the available roof area of the shipping building and covers 45 percent of the building's electricity needs. The annual CO₂ savings of around 103 tons underscore the considerable environmental protection potential of large-scale solar installations on industrial buildings.

This system demonstrates the scaling effects of modern photovoltaic technology, as it achieves a disproportionate increase in energy yield and CO₂ savings despite a more than sixfold increase in solar surface area compared to the first system. The strategic use of the large, often unused roof areas of industrial buildings proves to be particularly efficient for decentralized energy generation.

Third facility: Administration building (August 2023)

The newest and third photovoltaic system was installed on the roof of the new administration building in August 2023. With over 450 panels covering approximately 900 square meters, it represents an impressive example of the optimal use of available roof space. Particularly noteworthy is the high self-consumption rate of 60 percent of the administration building's electricity needs, which underscores the efficiency of modern building-integrated solar systems.

The annual CO₂ savings of around 20 tons may seem lower at first glance than those of the second system, but reflects the typically lower energy consumption of administrative buildings compared to production and shipping facilities. The high self-consumption rate indicates that the system is optimally sized according to actual energy demand.

Overall balance and environmental impacts

Schiesser's three photovoltaic systems together achieve a remarkable annual electricity production of approximately 1,103 megawatt hours and CO₂ savings of around 163 tons. These figures illustrate the considerable potential of industrial companies to make substantial contributions to climate protection through the consistent use of renewable energies. The total area of over 5,200 square meters corresponds to about three-quarters of a football field and demonstrates the considerable unused roof space available for solar energy in industry.

The economic advantages of solar power systems extend beyond mere cost savings in electricity procurement. By feeding surplus energy into the public grid, Schiesser contributes to the regional energy supply and may benefit from corresponding feed-in tariffs. This dual role as both an energy consumer and producer positions the company strategically in a changing energy market.

New district heating project “Zeller Wärme am Klärwerk”

Schiesser's solar activities are part of a broader sustainability strategy that is also reflected in other collaborations. Of particular note is the partnership with the Radolfzell municipal utility company on the "Zeller Wärme am Klärwerk" (Zell Heat at the Wastewater Treatment Plant) project. This innovative initiative utilizes the wastewater temperature from the neighboring treatment plant to generate heat and is scheduled to be operational by the end of 2026.

The project operates via a wastewater heat recovery system that uses three heat exchangers to extract heat from the water and transfer it to a large heat pump. The heat pump is powered by regionally sourced green electricity, further increasing the system's environmental friendliness. A buffer storage tank ensures a reliable supply during periods of high heat demand.

Schiesser's decision to participate in this district heating project underscores the company's commitment to using climate-friendly alternatives not only for electricity generation but also for heat supply. Andreas Lindemann emphasizes that this project represents "a further step forward for us in the area of sustainability.".

Impact of the Solar Peak Act 2025

The Solar Peak Act, which came into force in March 2025, brings significant changes for operators of photovoltaic systems. The most important changes are:

No feed-in tariffs when electricity prices are negative: In the future, new PV systems will no longer receive feed-in tariffs if the electricity price on the exchange falls into negative territory. This regulation is intended to prevent overproduction and promote self-consumption as well as the flexible use of electricity storage systems.
Mandatory smart metering systems: All new PV systems with a capacity of 7 kWp or more must be equipped with a smart meter and a control box. Systems without this technology may only feed a maximum of 60% of their nominal capacity into the grid until installation.
Adjustment of feed-in tariffs: The feed-in tariff for newly installed photovoltaic systems has been slightly reduced. For systems up to 10 kWp, the tariff is 7.96 cents/kWh (partial feed-in) and 12.60 cents/kWh (full feed-in).

These changes do not directly affect Schiesser, as the existing systems are grandfathered in. However, should the company plan further photovoltaic systems, these new regulations would have to be taken into account. The focus on high self-consumption, as already practiced with the third system, already aligns with the intention of the new law.

Further sustainability initiatives at Schiesser

In addition to investments in renewable energies, Schiesser also focuses on sustainability in other areas:

Sustainable product development

The “SCHIESSER SUSTAINABLE” label identifies products that consist of at least 70% sustainable materials and are manufactured in certified facilities committed to adhering to corporate social responsibility standards. Approximately two-thirds of Schiesser's products already bear this label.

Circular economy

Since July 2024, Schiesser has been using recycled clothes hangers, produced in cooperation with its Cologne-based partner company Willpütz. These hangers consist of 60 percent ECO PS, which is obtained from the recycled material of old refrigerators. The remaining 40 percent also comes from recycled materials, primarily from returned clothes hangers.

Sustainable Collection

Schiesser's Spring/Summer 2024 collection draws its visual and tactile inspiration from nature. Many materials are sustainable and adhere to the SCHIESSER SUSTAINABLE label. In addition to organic cotton, viscose and linen are also used.

Significance for the regional energy transition

Schiesser's photovoltaic initiatives have an important signaling effect beyond the company itself, impacting the regional energy transition in the Lake Constance region. The close collaboration with the Radolfzell municipal utility on both the solar power plants and the district heating project demonstrates how local energy suppliers and industrial companies can contribute synergistically to decarbonization.

Joachim Kania, sales manager of the Radolfzell municipal utility company, emphasizes that the partnership with long-established companies like Schiesser provides "additional impetus" for the energy transition in Radolfzell. This type of public-private cooperation could serve as a model for other regions facing similar challenges in the transformation to sustainable energy systems.

The Radolfzell municipal utility company offers various models for promoting photovoltaic systems, including investment projects, leasing models, contracting models, and tenant electricity models. This variety of options makes it easier for companies like Schiesser to find the form of solar energy use that best suits their needs.

Energy of the future: Schiesser shows how companies can act sustainably

The commissioning of Schiesser's third photovoltaic system in August 2023 marks an important milestone in the long-established company's sustainability strategy and impressively demonstrates the potential of industrial solar energy. With a total output of over 1,100 megawatt hours annually and CO₂ savings of 163 tons per year, the company is making a substantial contribution to the regional energy transition.

The gradual expansion of solar capacity from 2020 to 2023 demonstrates not only technical innovation but also strategic foresight in energy planning. The combination of high self-consumption rates and grid feed-in optimally positions Schiesser in the evolving energy market and creates both ecological and economic added value.

With its commitment to the district heating project “Zeller Wärme am Klärwerk” (Zeller Heat at the Wastewater Treatment Plant), Schiesser is taking the next step towards holistic sustainability. Given the new regulations introduced by the Solar Peak Energy Act 2025, the company is already well-positioned with its strategy of maximizing self-consumption.

The successful implementation of this solar strategy, complemented by further sustainability initiatives such as the district heating project and the use of sustainable materials, establishes Schiesser as a pioneer of sustainable industrial practices in the region and could inspire other companies to follow similar paths. The close cooperation with local energy suppliers also demonstrates how public-private partnerships can effectively advance the energy transition.

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