Retrofitting and refurbishment
From a portent to a power station: the inner structure of this air raid bunker, dating from 1942−43 and located in a working-class area within the Reiherstieg district, was destroyed by controlled detonations after World War II, and the giant edifice, with its concrete walls up to three metres thick, sank into a sixty-five-year slumber.
Following lavish redevelopment, the “Energy Bunker” now serves as a model for intelligent, decentralised energy supply – as a power station, it provides electricity and heat for the neighbouring “Global Neighbourhood”, and other places within the district, and, as a viewing platform, presents panoramas from the Elbe Islands to Hamburg city centre.
The café and an exhibition on the history of the structure, installed above, have made it a popular day trip destination; around 60,000 people alone visited in 2013, the IBA Presentation Year. The photovoltaic modules mounted on the south façade and the solar thermal collectors on the roof proclaim afar the building’s new purpose.
The interior, about twenty-seven metres high and lined with columns, is a sort of inner sanctum, with more energy generation and storage units, including various combined heat and power (CHP) plants and a 2,000-cubic-metre heat storage reservoir filled with water. The “Energy Bunker” is also setting the standard for local heat grids worldwide. Its iconic status for the IBA Hamburg and the Elbe Islands encourages a change of perspective within Hamburg and far beyond.
The total cost of the project comes to around € 27 million, of which approximately € 11.7 million was spent on the technology and the heat grid (excluding the solar casing). This money was boosted by the European Union, with around € 3.1 million from the ERDF (European Regional Development Fund). The solar casing was also supported by funds from the Hamburg Climate Protection Concept.