Energy-based optimisation of the Hamburg Water Cycle in the Jenfelder Au urban neighbourhood
|Location of local community||Hamburg, 22045 , Hamburg|
|Settlement in figures||Surface area: 755.3 km² ; Inhabitants: 1,786 million|
|Developer, organizer||Development: Wandsbek district authority and HAMBURG WASSER|
|Settlement||770 accommodation units, of which 630 are in new-build schemes, predominately 2-4-storey town houses, multi-storey apartment buildings up to 6 storeys|
|Settlement area||35 ha|
|Heating system||Approx. 200 accommodation units will be supplied with CHP heating generated from black water produced in neighbourhood; planned generation of heat in geo- and solar thermal plants for entire neighbourhood with distribution in a district heating network|
|Ownership structure||Site owner and site marketing: Finanzbehörde Hamburg|
The new Jenfelder Au urban neighbourhood is being developed on the site of a former army barracks in the Hamburg district of Wandsbek. It will provide a total of 770 accommodation units for around 2,000 residents, of which 630 will be in new buildings. The intention is to create affordable accommodation for families in the city by providing detached, semi-detached and terraced housing (predominately 2-4 storey townhouses) and multi-storey apartment buildings (up to six storeys) along with the accompanying social, cultural and commercial infrastructure.
In addition to state-of-the-art thermal insulation standards, it is intended to implement an innovative, holistic wastewater and energy recycling concept as a demonstration and research project. The “HAMBURG WATER Cycle” technical concept from Hamburg’s municipal water company, Hamburg Wasser, envisages a separate collection of wastewater from toilets (black water) and other domestic wastewater (grey water). The black water will be concentrated using vacuum technology and, together with organic waste, converted into biogas in a biogas plant. This in turn will be transformed into electricity and heat in a CHP plant. The generation of renewable energy shall be supported using geothermal and solar thermal heat in order to supply CO2-neutral heating through a local heating network. In addition, the residue from the biogas plant shall be used in the long term to produce high quality products for improving and fertilising the soil. Priority shall be given to using both the energy-related and material products in the Jenfelder Au urban neighbourhood. Grey water will be fed into an energy saving, decentralised wastewater treatment system and the residue from the treatment shall also be used as a co-substrate for the fermentation.
In the new model urban district of Jenfelder Au it is intended to combine neighbourhood-related environmental protection with a high urban design quality by adopting new approaches to housing wastewater management and local heating supplies: the energy-related potential of the wastewater is utilised and synergies are created between the infrastructure systems.
In the project, various versions of the HAMBURG WATER Cycle (HWC) concept will be compared in energy and economic terms for the new-build sector, ranging from homes to the wastewater disposal and the heating provision. For the purpose of recycling the fermentation residues from the biogas plant, practical, legal and organisational aspects are being examined with the aim of recycling materials in agriculture, while experiments to treat the fermentation residues are also being conducted. The different recycling possibilities are being assessed in economic and energy terms.
The various possibilities for treating the grey water are being compared by evaluating literature in regard to the practical underlying conditions in the Jenfelder Au urban district and, in particular, assessed in terms of the energy consumption. Practical aspects such as possibilities for using the grey water thermally, permits required under water legislation and the possibilities for recycling grey water are also being investigated. In addition, various concepts for the security system for the vacuum network are being compared and assessed in terms of their susceptibility to faults, operating costs and energy efficiency.
The HAMBURG WATER Cycle concept is being further developed with the aim of optimising the energy use. In regards to the separate black water collection, the implementation of the HAMBURG WATER Cycle in Jenfelder Au is based on using vacuum toilets and a vacuum sewage system. This has the advantage that it concerns already proven components that can now be accordingly adapted for use in Jenfelder Au. Possible alternatives for collecting black water are provided by newly developed toilet systems. Prototypes shall be used to investigate new kinds of alternative toilet systems and their impact on the technical design of the HWC. This investigation shall range from the domestic installations and the transport in the public sector to the recycling of the black water.
These concepts will be compared in energy and economic terms and investigated with a view to transferring the concepts to other urban districts.
The activities as part of EnEff:Stadt supplement the work funded by the German Federal Ministry of Education and Research as part of its FONA programme and are intended to promote the implementation and further development of the HAMBURG WATER Cycle in Jenfelder Au and at other sites.