The IBA Energy Bunker was officially launched on 14 October with the unveiling of the European Regional Development Fund's plaque. The former air raid bunker is located in Hamburg's district of Wilhelmsburg and has been transformed into an Energy Bunker as part of the 2013 International Building Exhibition Hamburg (IBA). This massive building, which had been derelict for several decades, now hosts a regenerative power plant supplying the surrounding area with green energy. The project is part of the ‘Renewable Wilhelmsburg’ climate protection scheme, which aims to provide the 50,000 residents of Wilhelmsburg with CO2-neutral electricity by 2025 and with climate-neutral heating by 2050.
During the official opening ceremony, Uli Hellweg, managing director of the International Building Exhibition, stated: "After more than 60 years of lying vacant, and following a project development and construction phase of seven years, this war memorial now symbolises our journey into a climate-friendly future. This Energy Bunker does not only generate clean energy for the surrounding residential quarter, it also demonstrates how local resources can be utilised for producing and storing heat. But the Energy Bunker also invites you to visit the viewing platform, its permanent exhibition and its café. To date, the Energy Bunker has had almost 100,000 visitors."
The household energy for the surrounding neighbourhood is generated by an efficient combination of energy sources: besides solar energy and biogas, the bunker also uses wood chips and waste heat from a nearby industrial plant, supplying heating energy to local households. The project's most innovative feature is its large-scale buffer storage facility with its 2 million litre capacity. The buffer storage facility integrates different eco-friendly heat and power units that are part of the Energy Bunker.
But the Energy Bunker also feeds the renewable power generated by its solar panels into Hamburg's electricity grid. In this way, the Energy Bunker has been supplying local households with electricity and heat for more than one year to date. Once fully completed, the bunker will generate approximately 22,500 megawatt hours of heat and almost 3,000 megawatt hours of electricity, thereby meeting the heating requirements of approximately 3,000 households and the electricity requirements of around 1,000 households. This will lead to CO2 savings of 95 percent, the equivalent of approximately 6,600 tonnes of CO2 per year.
Erected in 1943 as an air raid bunker, the original building protected thousands of people from Allied air raids. Four years later, the British Army destroyed the interior of the bunker by means of a controlled detonation. All that was left was the outer shell with its almost 3m-thick walls and its nearly 4m-high ceilings. For almost 60 years, the building served as a war memorial and any further utilisation of the premises was restricted to a few adjacent areas. In the context of the International Building Exhibition, the inside of the bunker was finally gutted, and a regenerative power plant with a large-scale heat reservoir was installed. The construction process was based on the concept of uncovering the building's original façade to ensure that the bunker retains its quality as a war memorial.