This former Nazi bunker is big enough to hold 80 single-family homes, TreeHugger reports. While its original purpose was as a stronghold for up to 30,000 people, after post-WWII unsure the building is now set to become Europe's largest solar power plant.
The plant is expected to serve 3,000 households with heat -- 1,000 of which will also get electricity. TreeHugger has more on the refurbishing of the building located in the Wilhelmsburg district of Hamburg:
The nine story structure (called a Flaktürme in German) will boast a 110 kWh rooftop photovoltaic system and a south-facing 0.6 GWh solar-thermal unit come 2012. The building's interior is being reserved for even further expansion. By 2013 the structure will house a 10.5 GWh woodchip combined heat and power plant (CHP), and a 3.7 GWh biomethane plant powered by a nearby industrial plant, for example. Waste heat will also be stored.
Re-tooling of the bunker is being orchestrated by the IBA Hamburg Gmbh. IBA, which had its inaugural year back in 2007, stands for Internationale Bauausstellung (International Building Exhibition in English).
The Flaktürme will get a new name when it's fully transformed into the renewable energy plant in 2013: Energiebunker.
Spiegel Online International provides the local perspective of the project from earlier this year:
By homing in on the Hamburg district of Wilhelmsburg, the IBA team wants to provide a small-scale showcase to demonstrate what a sustainable cityscape could look like.
"We are doing something new, bringing energy production into the center of the urban environment." Karsten Wessel, coordinator of the IBA's Cities and Climate Change project, told SPIEGEL ONLINE. "In Germany we already have settlements which are 100 percent self sufficient when it comes to energy, but they are mostly rural."
Still, the bunker project has met with a mixed reaction from locals. Margaret Mackert who is creating a documentation center about the flak tower, said the site is significant and its history must be preserved. "For older people who were children during the war, the bunker is mostly seen in a good light, as offering protection. Younger people see it as an ugly and threatening memorial -- but they know it is important that it stays."
In addition to being a power plant, the building will also feature a cafe and museum about the building and the local area, TreeHugger reports.