An air raid bunker from the times of World War II in Hamburg, Germany, has found new life as a landmark renewable energy disseminator.
Till 2011, this unassuming structure stood like a silent sentinel in the midst of a burgeoning residential neighbourhood. In the midst of 21st century sensibilities, this building was a throwback to another era, a totem of a violent past.
The ‘Energy Bunker’, as it is known today, used to be a decrepit bunker built in 1943, during World War II, standing at Neuhöfer Strasse in the Hamburg-Wilhelmsburg quarter. The British Army tore down its insides in 1947, but thought it too dangerous for the surroundings to demolish it completely. So, it remained, a brooding concrete hunk waiting to be assigned a new life and purpose.
That came in the form of a project imagined under the Internationale Bauausstellung IBA Hamburg (International Building Exhibition), made possible together by IBA Hamburg and Hamburg Energie.
The year 2006 marked the germination of the idea and the initial conceptualisation; four years later, in the year 2010 to be precise, static tests were conducted. Work on its reform, and its safety, began in earnest only in 2011. European Regional Development Fund (ERDF) and the Hamburg Climate Protection Concept provided the valuable funding needed to realise this renovation project.
As remarkable as its back story is, The Energy Bunker’s future prospects promise to be a phenomenon made in energy-efficient heaven. The British Army’s raid had ensured the demolition of 6 of the 8 floors of the building, but had left the outer shell untouched. In its new avatar, the Energy Bunker has been built to provide clean heat energy to most of the Reiherstieg district, where it stands.
This scheme also includes the production of renewable power that will flow into the electricity grid. Its capacity of 22,500 megawatt hours of heat can provide for the needs of close to 3,000 homes, and the 3,000 megawatt hours of electricity can light up approximately 1,000 homes. This accounts for a saving of about 6,600 tonnes of carbon annually.
The fulcrum of the project is a large heat reservoir, with a monstrous capacity of 2 million litres. This reservoir is central to the bunker’s heat producing power. It acts as a massive heat buffer system, and is fed by a brilliant combination of fuel material.
The four-pronged fuel system here features a biomethane-fired thermal power plant; a wood burning unit; a solar thermal system on the roof; and waste heat generation from an industrial unit nearby.
In addition to its fantastic renewable energy credentials, the Energy Bunker’s renovation has ensured the attraction of tourists and enthusiasts, keen on absorbing the relic’s new form and substance.
As IBA director, Uli Hellweg, stated during the bunker’s opening ceremony and plaque-unveiling in October 2013, “Not only does it produce clean energy to supply the district, but also demonstrates how local resources can be used to produce and store heat. With its viewing platform, permanent exhibition, and café, the ‘Energy Bunker’ also makes an appealing visitor attraction. Almost 100,000 people have visited the ‘Energy Bunker’ so far.”
The Vju Café has been built at a height of 30 meters into one of the flak towers of the bunker, and has a beautiful cantilevered platform that runs around the building and offers panoramic views of Hamburg.
Built at a cost of €27 million, The Energy Bunker represents a conceptual landmark, and sets a valuable precedent in the controlled and practical use of hydraulic energy in providing for the needs of small and large townships. An exhibition on the bunker’s remarkable journey realised in collaboration with Geschichtswerkstatt Wilhelmsburg (Wilhelmsburg & Harbour History Workshop), helps visitors better understand the scale of, and effort pooled into, the project.
And what is also cherry on the cake is that The Energy Bunker stands in great company – its eastern neighbour is the Georgswerder Energy Hill, Hamburg’s largest open photovoltaic system. Talk about energy-efficient community spirit.
Text By Shruti Nambiar
Photographs Courtesy IBA Hamburg GmbH, Bernadette Grimmenstein, Martin Kunze