Notable for its monumental 42 metre concrete façade, the former flak bunker dating back to World War Two is now a characteristic feature of the urban image of Hamburg-Wilhelmsburg. Elaborately renovated and converted as part of the International Building Exhibition, IBA, today's power plant using renewable forms of energy supplies the surrounding residential district with clean energy and green heat. The Energy Bunker also offers a café and exhibition zones inviting visitors on a tour of discovery. ERCO lighting solutions create a stunning impression of depth in the rough-textured interior with its massive water tank used as a heat store. Neutral white light effectively illuminates the concrete façade allowing it to stand out in the dark. Grasshopper luminaires are used to produce the optimum long-distance effect responding with sensitivity to the historic heritage of the war monument using discreet lighting from below.