Solar energy powers Stockholm’s iconic Åhléns City department store with high-efficiency back contact technology from LONGi

On a busy corner of central Stockholm, Åhléns City has been part of everyday life for generations. The department store on Klarabergsgatan is a familiar meeting point for locals, a landmark for visitors, and an architectural symbol of Sweden’s post-war retail era. Today, this historic building is taking a visible step into the future by generating its own renewable energy.

A familiar landmark takes a step into the future

The property owner, Ramsbury Property, together with long-standing tenant Åhléns, has installed a rooftop solar system that now supplies the building with locally generated electricity. The installation uses LONGi’s latest Hi-MO X10 high-efficiency back contact modules and is expected to produce around 375,000 kWh of renewable electricity each year. That is roughly equivalent to the annual electricity consumption of up to 95 average Swedish households. The solar power is used directly on site, reducing CO₂ emissions while strengthening the building’s long-term sustainability profile. With this capacity, the project ranks among the largest rooftop photovoltaic installations within Stockholm city.

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Beyond the environmental impact, the project also makes economic sense. Producing electricity on site improves operational income while increasing the long-term value of the property, an increasingly important factor for urban buildings facing rising energy costs and sustainability expectations.

The system was developed and built by Luminos Energi, a long-standing partner of LONGi Solar with deep experience in Nordic rooftop projects. Christian von Koch, founder and CEO of Luminos Energi, explains why the choice of technology mattered. “Our decision to partner with LONGi Solar and deploy the Hi-MO X10 back contact modules was driven by their proven performance and durability under Northern European conditions. In a region where weather and light conditions can be challenging, we need technology that delivers reliable yield over decades. That confidence is essential for customers who expect consistently high performance.”

Precision and exceptional care - why installing solar on Åhléns City took more than a year of planning

Installing solar on Åhléns City was far from a standard rooftop project. The building’s distinctive copper roof and protected façade required tailor-made engineering solutions and careful planning. The design phase alone took more than a year, with close coordination to ensure safety, durability, and visual integration that respected the character of the historic structure. Only part of the building’s approximately 8,000 square meters of roof area could be used, making efficiency and system design even more critical.

LONGi’s Hi-MO X10 back contact modules were selected for their combination of high efficiency, reliability, and robust construction. The HPBC 2.0 back contact architecture, based on n-type TaiRay wafers and a zero-busbar design, helps reduce shading and hotspot risks while enhancing mechanical strength. These characteristics are particularly valuable for complex rooftops like Åhléns City, where performance and resilience must go hand in hand.

“This project shows what is possible when technical precision meets strong local partnership,” says Will Han, General Manager for LONGi Nordics (DG). “Installing a high-efficiency system on a heritage copper roof in the center of Stockholm required close collaboration and technology that performs reliably under Nordic light conditions. The Hi-MO X10 modules deliver that balance, allowing solar to integrate naturally into a complex urban environment.”

Built in the early 1960s and owned by Ramsbury since 2001, the property known as Gripen 12 reflects an important chapter in Stockholm’s urban development. By integrating on-site solar generation, Åhléns City is now adding a new chapter to its story, one that connects architectural heritage with modern sustainability.

As Sweden continues its transition toward national climate targets, projects like Åhléns City show how renewable energy can be thoughtfully integrated into existing cityscapes. For LONGi, the installation represents another milestone in supporting technically demanding rooftop projects across the Nordic region. For Stockholm, it is a reminder that even the most familiar buildings can evolve, quietly producing clean energy above the city streets while remaining true to their history.

Watch the project come to live here:

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