Using the example of the Postsiedlung housing estate in Darmstadt, the researchers are developing a restructuring strategy that links the use of energy-efficient technologies and integrates renewable generation and storage concepts. The new strategy is ideally modular in order to be transferable to similar housing estate structures. Using a newly developed energy-plus module, it is intended to increase the density of the four existing buildings in the Darmstadt housing estate being investigated in the research project.
Buildings and their energy management are currently largely considered on an individual basis. Energy-plus houses are also mostly designed on an individual basis. Although they provide surplus energy in the annual balance, they make use of the public grids as a buffer, and can therefore contribute to their overloading. Energy-plus housing estates, on the other hand, attempt to ensure the energy balance throughout a group of buildings. However, so far they have been realised exclusively in selected development areas so as to minimise disruptive variables. The cumulative consideration of the generation and consumption of electrical energy creates aggregation effects that smooth out the overall consumption. This enables the stochastic proportion of the consumption to be reduced. This facilitates decentralised provision and at the same time reduces the transport losses and the need for compensation mechanisms at higher network levels. Bundling technologies at the housing estate level (for example, CHP plant, storage systems) creates additional benefits in terms of the investment and operating costs.
Systems with different characteristics are required to generate and store the energy. In order to minimise the costs, different energy technologies can be combined to form hybrid systems and constellations.
In the SWIVT research project, housing estate modules are being configured and refurbishment strategies and concepts developed at the district level. The research will focus on utilising technological innovations, linking different areas and players and developing modern methods for the monitoring and energy management.
As part of the research project, four existing buildings are being refurbished and linked together using a newly developed "energy-plus module" (heat and electricity produced using PV, solar thermal and possibly CHP). The aim is to increase the residential space. The project can be divided into three phases. Based on a high-resolution, energy-related analysis of the existing housing estate, the first phase will be concerned with developing an energy-positive module in conjunction with the developer Bauverein AG, the energy provider HSE AG and specialists for innovative energy components. Based on the determined load profiles, the second phase will involve the development of energy generation and storage systems at the component level in conjunction with AKASOL GmbH, the construction of prototypes and the design of a master control logic. The third phase includes the trial operation of the individual components as well as the validation of the control system using the linked subsystems. An ecological and economic evaluation of the systems will also be conducted in parallel.
District concept and urban development
The basic two- to three-storey residential buildings in the Postsiedlung housing estate in the Darmstadt district of Bessungen were constructed in 1949 by a housing association in order to create workers' dwellings. In order to increase the volume and density of the residential space, several rows of 1950s buildings outside the project’s section of the housing estate have already been increased in height by two storeys in recent years. Although the other buildings have not yet been renovated, there are also plans to refurbish them. To apply the "energy active" housing estate module, a smaller, two-storey building has been selected, which is planned to be fully renovated. The energy consumption (final energy) of the existing residential buildings corresponds to the un-renovated building standard of the period when they were constructed. They currently lie 3 to 4 times higher than current energy efficiency standards.
The existing building stock provides the critical mass in meeting energy policy targets in the next few decades. The efficient use of energy will become the focus in renovation projects. Strategies for generating and storing energy locally will also, however, play an increasing role. The aim of the SWIVT project is to develop a refurbishment strategy for the Postsiedlung housing estate in Darmstadt – combined with renewable generation and storage concepts using innovative energy technologies. The strategy being developed will ideally be modular to enable it to be transferred to similar housing estate structures. The approach envisages the densification of the existing buildings with an "energy positive" housing estate module. In addition to high quality residential space, the module consists of innovative components for generating, storing and connecting electricity and heat as well as a thermoelectric control concept. This makes it possible to considerably improve the energy balance of the housing estate in one step – with minimal intervention in the existing building stock. The housing estate module also acts as a generator for sustainable district development, for example by improving the acceptance of innovative technologies such as energy storage systems.
|Gross floor area, before||8.056 m²|
|Living area, total||8.056 m²|
|No. of residential units||79 WE|
|SOI (Site Occupancy Index)||0,16 SOI|
|FSI (Floor Space Index)||0,77 FSI|
|Utilisation type, State of construction and refurbishment, Age structure||Purely residential , Poor – requires considerable refurbishment, Built between 1949 and 1957 (5 buildings)|
|Ownership structure||Renting through municipal building society|
|Heating system||Building-based central heating (natural gas),3 x individual gas-fired central heating systems (natural gas)|