Development of novel variable building skin with solar concentrating technology for obtaining energy benefits and optimizing indoor daylighting

Variable building skin, as an interface for human-environment interaction and communication, can adjust the state of the building skin according to the user's needs to optimize the indoor environment. However, many current variable building skin prototypes predominantly draw inspiration from the natural environment (bionics) or material properties, with limited consideration given to integrating solar energy resources, resulting in variable building skins lacking energy production performance. Simultaneously, this development mode also results in most current variable skins controlling the indoor light environment through reflection or shading, failing to maximize solar resource use, and even reducing indoor daylighting comfort. Therefore, it is necessary to explore the additional benefits of variable skins and develop novel energy production skins, which are driven by the goals of decarbonization and comfortable indoor daylighting environments. This study develops a novel variable building skin utilizing solar concentrating technology, with the aim of generating additional energy benefits and optimizing indoor daylighting. Additionally, we perform comprehensive simulations and comparative experiments on the newly developed energy production variable building skin to assess their performance and viability regarding energy production (additional benefits) and optimization of indoor daylighting (fundamental role). The simulation results show that the developed energy production building skin can optimize indoor daylighting and generate energy benefits. Compared to common skin and no skin, the energy production skin can generate a maximum of 5.73 kWh and a minimum of 0.84 kWh in a single day. Additionally, compared to no skin, it can increase the useful daylight illuminance (UDI) by a maximum of 9.36% and reduce the daylight glare probability (DGP) at the second viewpoint by a maximum of 16.71%. The energy production variable building skin maximizes using the sun's resources while balancing aesthetics and application. It can provide design inspirations and methods for transitioning variable building skins toward energy production skins.