After lunch we made our way to the Freiburg Solar Information Center. This building was a real estate development project intended to create a business incubator space for companies specializing in renewable energy and energy efficiency. Roughly 40 companies occupy this space, with businesses offering products and services to support the German energy transition, and to share this technology with the rest of the world. One of the larger tenants included a research unit of the Fraunhofer Institute (which provided some foreshadowing for one of tomorrow’s site visits). The Solar Info Center building is LEED platinum certified, and features a geothermal system, building integrated photovoltaics, solar thermal energy and a natural cooling and ventilation system.
We also visited the Bugginger Strasse 50 affordable housing development. This building was initially constructed in the post-war years, with a very inefficient energy consumption footprint of nearly 70 kWh/square meter. The city community development agency undertook an effort to retrofit the building and improve it to German Passive Haus standards of < 15 kWh/square meter. This included a total overhaul of the building envelope. Former balconies were enclosed and converted into conditioned space as part of the apartment interior. Twenty cm of ridged foam insulation was added to the exterior, which was also upgraded with new triple glazed windows. The building was connected to a new district heat system powered with a natural gas combined heat and power installation run by the local energy provider, Badenova. We finished our visit with a tour of the building’s rooftop mechanical room, which included a massive air-to-air heat exchange ventilation system. The room impressed us all with its spot free cleanliness. And thanks to the daylighting panels in the roof, this was also an aesthetically pleasing and brilliantly illuminated mechanical room, unlike any that we had ever seen.
We concluded a long day with dinner and conversation with Professor Eduard Heindl of Furtwangen University of Applied Sciences. Dr. Heindl shared with us information on his patented system for gravitational energy storage, and the efforts of his startup company to implement a field demonstration of a solar + storage system in the middle east. We also talked about his early work in the renewable energy sector, and his creation of the SolarServer website which became the largest such internet portal in Germany, during the .com technology boom of the 1990s.