Playful PV in Rome
The rhythm of the photovoltaic modules in the roof alternating with special low-reflecting glass panels is made to coordinate with the roof structure. The resulting bands of daylight illuminate the beauty of the original cast iron structural elements.
The museum's program did not originally call for photovoltaics, but once the designers introduced the idea, its fit with the museum's educational and environmental goals gave the technology a central role in the design.
In addition to its educational value, the roof improves the quality of natural light in the exhibit space and decreases the energy load of the building. More widely, the project serves to encourage the retrofit application of photovoltaic systems as a strategy in the restructuring and maintenance of other old industrial buildings.
The innovative power-grid-connected photovoltaic plant, located on the south-pitched roof of the main building, is expected to generate 18,000 kilowatt-hours per year. This energy will be used by the museum directly and is expected to save $2,200 per year in operating costs.
The photovoltaic design also integrates passive cooling and heating strategies which are expected to reduce the building's cooling load by 52.8 percent, and heating by 11.3 percent, yielding additional savings of about $4,000 per year.
The photovoltaic installation will reduce greenhouse emissions by 10 tons (9.3 tonnes) per year, compared to the conventional production of the same amount of electricity.
Assembling the PV Systems
The photovoltaic installation consists of two industrialized systems, with skylights and shading devices, to become an integral part of the pavilion. An 8.2-kilowatt photovoltaic system replaces sections of the old roof tiles with skylights, while a 7-kilowatt photovoltaic canopy system works with alternating fixed and movable canopies to shade the skin of the south facade, and allow controlled levels of daylight into the exhibit area.
The new canopies are supported on added, specially designed structural posts. These vertical telescope-shaped elements stand beside the existing cast iron columns, and echo the light "spider web" design of Polenceau's original roof structure.
The roof installation uses double-glass modules measuring 45 by 45 inches (1145 by 1145 millimeters), and covers a total surface of 1500 square feet (142 square meters).
The 7-kilowatt photovoltaic canopy system uses modules of standard glass and polyvinyl fluoride (PVF) film measuring 22 by 48 inches (555 by 1215 millimeters), covering a total surface area of 800 square feet (76 square meters).
To control costs, all modules were selected from Eurosolare's standard catalog. The motors and mechanical parts of the photovoltaic components were designed to simplify the mounting technology, reduce production, assembly, installation, and maintenance costs, and introduce a playful configuration for a friendly introduction to photovoltaic technology.
Financial assistance for the installation of the Children's Museum photovoltaic system, which is part of a larger European Union "THERMIE" program, came from Danish partner CENERGIA and Dutch partner ECOFYS.
The project complies with the Alborg Charter and other conventions on climatic change as formulated in the Twenty-first Agenda of Rome for sustainable development and outlined in the 1992 Rio de Janeiro Conference.
For children playing in the sunlight that illuminates the exhibit hall, a story of a sustainable future is there, in the exposed junction boxes and bright wires above them, vividly illustrated, and ready to engage curious young minds.