Dynamic photovoltaic building envelopes for adaptive energy and comfort management

Current efforts to improve building envelopes mostly focus on reducing energy demand by static measures such as insulation, selective glazing and shading. The resulting envelopes are limited in adapting to weather conditions or occupants’ needs and leave vast potentials for energy savings, onsite energy generation and improvement of occupant comfort untapped. In this work, we report on a dynamic building envelope that utilizes lightweight modules based on a hybrid hard/soft-material actuator to actively modulate solar radiation for local energy generation, passive heating, shading and daylight penetration. We describe two envelope prototypes and demonstrate autonomous solar tracking in real weather conditions. The dynamic photovoltaic envelope achieves an increase of up to 50% in electricity gains as compared to a static photovoltaic envelope. We assess energy savings potentials for three locations, six construction periods and two building use types. The envelope is most effective in temperate and arid climates, in which, for the cases analyzed, it can provide up to 115% of the net energy demand of an office room. Improvements in building envelope performance and onsite power generation are key to enabling zero-energy buildings. Here, Svetozarevic et al. present an adaptive solar facade driven by soft robotic solar trackers that allow both the modulation of daylight penetration and energy generation.