As a visible sign of the shift from fossil fuels to renewable energies, the former coal silo and heating plant of the machine factory Sulzer Burckhardt AG in the "Gundeldinger Feld" in Basel is covered with colored PV modules. As part of a research project this best practice building investigates new approaches for BIPV integration as cladding innovative materials and new energy storage strategies. As "Gundeldinger Feld" ensemble is under heritage protection, the remodelled building was required to match the style and colour scheme of the site and all the old industrial area has been reconverted in a new model energy district. The project is part of the "2000 Watt society - pilot region Basel". Solar Silo project that was rewarded in the "renovation" category with the 2015 Swiss Solar Prize.

BUILDING DESCRIPTION The building contained the coal silo and the heating plant for the industrial area named "Gundeldinger Feld". The coal silo "Kohlesilo" of the Sulzer and Burckhardt machine factory in Basel has been modernized and was completely converted into a multi-purpose building.

URBAN CONTEXT The former site of the Sulzer Burckhardt AG in the „Gundeldingen“ neighborhood in Basel has changed in the last 20 years from an industrial area into a vibrant place with a variety of uses. This transformation process of the „Gundeldinger Feld“ was accompanied by the establishment of cultural, social and commercial uses and has had a positive impact on the immediate environment and the neighborhood. The site is 40-80m x 160m in size and is located close to the center of town.

ELEMENTS WORTHY OF PRESERVATION The internal structure of the four coal silos was kept in the interiors, only internal doors were cut out of the concrete shafts. On the outside, the four shafts can be read by looking at the façade (four vertical sections in the façade).

CONDITIONS OF THE ENVELOPE After the connection to the heating network, the building containing the coal silo and the heating plant became free for other purposes. The nearly 20 meter high coal silo in the heart of the area was the only building that had not yet been repurposed, due to the economically unfavorable high envelope-to-floor ratio.

DESCRIPTION OF PRE-INTERVENTION BUILDING SERVICES The ground floor, the former heating plant, has been used for several years by a circus school for children.

RENEWABLE ENERGY SYSTEMS The building it heated with district heating.

PHOTOVOLTAIC Innovative coloured customized photovoltaic modules are used creating a particular visual design to be integrated in the ventilated roof and façade envelope of an industrial refurbished historical building.

As the „Gundeldinger Feld“ as an ensemble is under heritage protection, the remodeled building was required to match the style and color scheme of the site.

The cladding (facades south / north) consists of colored frameless photovoltaic modules and fiber cement panels. The entire roof is covered with colored and conventional PV modules. The modules are ventilated and serve as the water-bearing stratum.