A ‘smart’ building facade equipped with movable solar panels could substantially improve the energy efficiency of urban apartment and office buildings.

Solar panels are being installed on a growing number of vertical surfaces, especially on the facades of tall, glass-clad urban buildings. But, in general, such installations cannot adjust to changing weather and light conditions.

Arno Schlueter at the Swiss Federal Institute of Technology Zurich and his colleagues designed a dynamic building envelope to make the best use of incoming sunlight. The system includes robotically driven solar panels on a vertical facade. An algorithm computes the panel orientation that will provide an optimal balance of electricity generation, passive heating, shading and daylight penetration.

A prototype installed on one of the institute’s buildings generated up to 50% more energy than a static system. Intelligent solar-energy building envelopes are likely to be most effective in temperate and dry climates, the authors say.