Section through the Forestal Building and the applied Sun Wall.

Partial views of the Sun Wall in stationary and randomly moving positions.

Photovoltaic panels are applied to an array of 52 vertical trusses. Each truss is connected to the wall by an independent hinge. The tops of the trusses are free to move, stabilized by a counterweight, guide track and damping shocks. As the southern wind blows and applies pressure to the face of the wall, the trusses and their planes of photovoltaic panels gradually lean back. When the wind pauses, each assembly returns to a vertical position by the force of a counterweight and gravity. The 52 units act individually, allowing random variation in the movement and composition of the photovoltaic array.

The total photovoltaic area measures 64' high x 260' long, or 16,640 square feet. Using 16W/square foot as an approximation of the energy output for commercially produced photovoltaic panels, the sun wall acts as a 266kW system. Unused and off-peak energy production is passed directly to the utility grid and issued as a monetary credit to the building. Maintenance of the array is available at the front and rear of the panels. A locking device allows safe access and also serves to fix the panels during severe weather conditions.