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Ready-made energy centers with heat pumps: decarbonizing the heat supply in existing homes

Decarbonizing the heat supply of existing multi-family homes has played a major role in the success of the energy transition. However, the renovation rate is still lagging drastically behind the requirements and would have to be doubled in order to have a climate-neutral building stock by 2050. New approaches are needed to accelerate and improve the carbon footprint. One effective solution is prefabricated energy centers. These can replace fossil fuels with renewable energies while minimizing the impact on residents.

Breaking with fossil fuels

Decarbonizing the heating sector is one of the biggest challenges on the road to a climate-neutral future. Many existing buildings in particular need to be renovated to improve their energy efficiency because they are equipped with outdated, fossil-fuelled heating systems. Of course, the effectiveness of the refurbishment measures is important, but so is the speed with which they can be implemented. It is also important for homeowners to minimize the impact on existing tenants. One promising solution is prefabricated energy centers, which enable a quick and efficient conversion to renewable energies.

goodmen energy's renovation strategy for the decarbonization of existing buildings

Our renovation strategy follows a standardized approach to efficiently replace existing fossil fuel heating systems with climate-friendly solutions.

A structured approach


The development of the refurbishment strategy begins with a specific use case. During the analysis phase, the technical requirements and individual challenges of the property in question are precisely determined. Based on this, we develop tailor-made solutions that are tested for effectiveness and further optimized in pilot projects. By documenting the results, the aim is to create a repeatable and scalable method that can be used as a best-practice solution for broad application. Analogous to the Energy Sprong principle in the construction industry, we are attempting to find standardized procedures for certain building classes and local conditions that also take into account the cost/benefit factors and the value creation potential for the customer, for example housing associations. These are documented.

The multiplier effect


To accelerate the heating transition, we rely on multipliers. This means that our standard solutions can be quickly disseminated and implemented via partners and networks. This enables us to accelerate the roll-out of climate-friendly technologies and drive forward the energy transition across the board.

In our NETZ-WERK REGENERATIV, we can draw on bundled expert knowledge and holistic approaches to heat generation. The solutions we develop in the network are sustainable, robust and adaptable to different types of buildings. This strategy enables us to make the decarbonization of existing buildings cost-efficient and reliable in terms of planning.

Rapid refurbishment through scalable energy centers

Why do we see prefabricated solutions as a key to success?

  • Time factor - conversion in existing buildings with minimal disruption to residents
  • Cost factor - cheaper (pre-)production thanks to standardized procedures and building blocks
  • Avoid errors on the construction site
  • Reduce work on the construction site
  • Counteract shortage of tradesmen
  • Attractive offer for homeowners → more orders → accelerate the heating transition

We offer prefabricated solutions for detached or semi-detached houses with our source packages, for apartment buildings with the prefabricated energy centers, and - with the ComPons floating energy centers - for districts.

In apartment buildings, renovating the heating supply is often costly and involves longer construction times. This affects tenants through noise, dirt and heating and hot water failures, leading not only to increased expenditure but also to reduced income for property owners and housing associations.
Prefabricated energy centers offer an opportunity to carry out a refurbishment with minimal and justifiable disruption for tenants and at the same time enjoy the benefits of heat from renewable energies. The completely prefabricated energy centers are supplied in pre-installed modules so that installation and commissioning can take place within a very short time.
The standardized modules can be individually adapted and are fully equipped with heat pumps, buffer storage tanks and system controls. Some energy centers are installed above ground, others are buried in the ground - both offer the advantage that the former boiler room in the basement is freed up for other uses (or remains as a back-up).

Advantages of prefabricated energy centers

  • Time saving: Pre-installed (above-ground) energy centers can be installed very quickly, meaning that the heating for tenants is down for a maximum of two days. The complete installation usually only takes a week.
  • Preliminary work such as concreting the floor slab or house connections can be completed before delivery.
  • Cost efficiency: Serial production reduces production costs and the modular design means that energy centers are scalable and can be easily adapted and expanded to meet specific requirements. They arrive on site completely pre-assembled and only need to be connected.
  • Space saving: As the energy centers do not have to be housed in the basement, valuable space is retained for other purposes. Apart from the entrance, underground energy centers are virtually “invisible” and the area above can be used as a lawn, etc.
  • The façades of the energy centers can be individually designed and the roofs can be greened.
  • Maintenance of the system without access to the building. 
  • Flexibility: The modules are scalable and can be adapted to local conditions. This means that both individual buildings and larger neighborhoods can be efficiently supplied with renewable energy.
  • No noise disturbance in the house
  • Simpler, more cost-effective fire protection
  • Security benefits, protection against vandalism and unauthorized access
  • Increased value of the property
  • Future-oriented technology

Current projects in realisation

Pilot project in Marburg: 


A housing association from Marburg wants to convert its portfolio to a renewable heat supply. The pilot project comprises three blocks of flats, each with twelve residential units. The buildings, which were previously supplied by a gas heating system with a central boiler and a small heating network, will now be equipped with air source heat pumps. For this purpose, we are placing an above-ground energy center on a concrete foundation behind each building. To ensure trouble-free air intake, the area around the energy centers must be cleared of bushes within a radius of three meters. The six pre-installed heat pumps draw in the air via fins and supply each block with 60 kW of power. In doing so, we reduce the flow temperature from 85°C to 55°C without changing the house pipes. This change increases energy efficiency, reduces CO2 emissions by 76 tons per year and increases the value of the property.
Now that the pilot project has been successfully completed, a total of 260 residential units belonging to the housing association in two streets are to be newly supplied using this principle. The installation of the prefabricated energy centers takes one week, whereby the heating outage is usually limited to just two days.

Floating energy centers on the Vltava River in Prague


In Prague, an innovative concept has been developed in which floating energy centers are installed on pontoons in the Vltava River. These mobile units are particularly suitable for urban districts and new development areas where a fixed installation is not possible due to lack of space or monument protection regulations. The energy centers can produce outputs of up to 15 MW and offer a flexible and fast way to decarbonize urban areas. All prefabrication takes place in shipyards and the floating units are transported directly to the site by water. The time frame from order to commissioning is only 12 to 18 months.

These projects illustrate how versatile the possible applications of prefabricated energy centers are - from supplying urban apartment blocks to listed old towns and industrial applications. Thanks to the scalability and flexibility of this technology, both smaller apartment buildings and large-scale industrial plants and residential areas can be supplied with energy efficiently and sustainably.

Prospects

A key issue when renovating existing buildings is the often limited space available for installing new technologies. Prefabricated energy centers offer an ideal solution here, as they can be installed flexibly above or below ground without taking up valuable space in the building. What's more, the prefabricated standard modules not only do not require planning permission, they are also quick and easy to install, which speeds up the renovation process considerably.
The decarbonization of the heat supply in existing multi-family houses can be significantly accelerated with prefabricated energy centers. The combination of quick installation, cost efficiency and high flexibility makes this solution particularly attractive for owners and housing associations who want and need to reduce the CO₂ emissions of their buildings while cutting energy costs. By using renewable energies and intelligent system controls, prefabricated energy centers offer a future-proof and scalable solution that makes a significant contribution to the energy transition.
Since 2021, the Bafa (Federal Office of Economics and Export Control) has paid out over ten billion euros in subsidies for energy-efficient refurbishment. 1.55 million applications have been submitted.