Main Light by ttal is a self-sufficient lighting installation developed along the Main riverfront in Frankfurt, Germany, by Munich-based studio ttal in collaboration with Italian lighting manufacturer ewo. Presented as part of the World Design Capital 2026 initiative, the project explores how renewable energy infrastructure can become an integrated and visible component of public space through autonomous solar-powered lighting systems.
The installation introduces a new generation of off-grid streetlights that generate renewable energy directly at the point of use through translucent organic photovoltaic (OPV) solar foils. Developed in response to increasing urban energy demands, light pollution, and the environmental impact of conventional public lighting systems, the project rethinks street infrastructure through the concept of ‘prosumers,’ systems that both consume and produce energy.
Unlike traditional urban lighting, which depends on underground electrical networks and extensive site intervention, Main Light operates through lightweight autonomous structures that require no wiring or permanent ground excavation. The modular system allows for flexible installation with reduced material use while supporting lighting solutions for both urban environments and underserved public spaces.
Main Light rises next to the Main river, transforming Frankfurt’s skyline | all images courtesy of ttal
The project also addresses the ecological effects of artificial illumination on humans, plants, and nocturnal ecosystems. Lighting systems are designed using full cut-off technology, intelligent demand-based controls, and a warm-spectrum light source intended to reduce ecological disturbance while maintaining visibility and orientation within public space.
During daytime conditions, the translucent solar surfaces function as visible energy-generating elements within the cityscape. Their colored panels cast changing shadows and filtered light patterns across the riverside, creating shaded gathering areas and reinforcing the installation’s presence as an urban spatial device rather than concealed infrastructure. At night, the structures emit controlled low-impact illumination that balances public accessibility with environmental sensitivity. Through this dual role as both energy generator and lighting system, Main Light positions renewable infrastructure as an active architectural and public element within the urban environment.
The first pilot installation by ttal’s designers Tobias Trübenbacher and Andreas Lang transforms a section of Frankfurt’s riverfront into a testing ground for autonomous public infrastructure that combines renewable energy production, lighting design, and spatial activation. The project was realized in collaboration with ewo GmbH for lighting and control technology, ASCA GmbH & Co. KG for organic photovoltaic systems, Schake GmbH for steel construction and reversible concrete foundations, and merz kley partner GmbH for structural engineering.
Main Light operates off-grid on reversible foundations that also function as urban furniture
Studio ttal refined the installation’s form and proportions through a series of physical scale models
Main Light is entirely self-sufficient, requiring no complex electrical infrastructure
translucent OPV solar sails create dynamic shifting patterns of light and shadow across the structure
shielding elements and warm, insect-friendly light spectrum reduce light pollution and ecological disturbance
daylight transforms the solar surfaces into colorful canopies
colored OPV panels turn renewable energy generation into a visible and playful public-space element
the design of the luminaires is configured to optimally align the OPV foils with the position of the sun
intelligent demand-based lighting control system by ewo activates illumination only when needed
project info:
name: Main Light
designer: ttal – Tobias Trübenbacher | @tobias.truebenbacher, Andreas Lang | @andreas_lang____
lighting and control technology: ewo GmbH
innovative OPV technology: ASCA GmbH & Co. KG
steel construction and reversible concrete foundations: Schake GmbH
static calculations: merz kley partner GmbH
location: Frankfurt, Germany
designboom has received this project from our DIY submissions feature, where we welcome our readers to submit their own work for publication. see more project submissions from our readers here.
edited by: christina vergopoulou | designboom
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