The Zollverein Foundation intends to commission the development of a feasibility study UNESCO World Heritage Zollverein - Climate Neutral 2030.

The UNESCO World Heritage Site Zollverein in Essen is a landmark of the Ruhr area, a monument to industrial culture and a symbol of the transformation of what was once the world's largest coal mine into an attractive location for culture and leisure, education and business. Today, Zollverein stands for an identity-creating culture of remembrance in the Ruhr area and at the same time for forward-looking location development.

The site of the UNESCO World Heritage Site Zollverein covers around 100 hectares. Since the closure of the mine in 1986 and the coking plant in 1993, the buildings and facilities have been successively renovated and prepared for new uses.

The buildings are used as museums, exhibition and event halls, depots, offices and studios. The individual buildings have to meet very different requirements.

As the owner of the properties, the foundation would like to begin in 2023 to identify the options for action that would enable the climate-neutral operation of the UNESCO World Heritage Site Zeche Zollverein. Zollverein as a future location with tradition would thus represent the structural change in the Rhine-Ruhr region as a lighthouse and thereby build on the tradition as an energy location by identifying and tapping the entire above- and underground energy potentials.

In view of the rising mine water level (in the period up to 2030) at the Zollverein site to -630 m above sea level in the long term and the conversion of the Zollverein 2 and 12 shafts (Fig. 1) to safety wells, there are potential mine water utilisation scenarios (28 - 35 °C). As part of the planned investigation, it must be determined to what extent the mine water can be used for a regenerative energy supply of the entire site.

Another potential is the existing roof and parking areas, which offer space for photovoltaic and solar thermal systems.

In order to achieve the ambitious goal of being able to operate a historic, listed ensemble in a climate-neutral manner, a feasibility study should first be carried out, not least to estimate which investments will be caused by the identified renovation scenario. On the one hand, the energy system must be decarbonized, on the other hand, it is necessary to significantly reduce the primary energy demand of the site.

Required services:

a) Use of mine water and solar energy

As part of the planned heating and, if necessary, cooling supply on the grounds of the Zeche und Kokerei Zollverein it is planned to use mine water as a geothermal energy source. The focus of the feasibility study is the development of scenarios for the provision of heating and cooling or storage, the use of photovoltaics and solar thermal energy. It is also necessary to examine the extent to which a neighbourhood solution is possible beyond the World Heritage.

For the use of photovoltaics and solar thermal energy, an overall concept for the location must be created, which not only clarifies the technical and legal concerns, but also ensures in particular the architectural, design and coordination with the monument authorities.

b) Inventory, analysis, energy efficiency and concept of measures

As a basis for the development of the supply concept, the existing buildings and the existing supply infrastructure must be recorded and energetically evaluated.

The concrete need for action is to be examined and demonstrated. The structural and energetic weak points of the buildings and their technical equipment are to be documented and an assessment of the structural urgency is to be made. Taking into account synergy effects and cost-reducing aspects, suitable packages of measures are to be put together and the savings potential is to be identified.

Here, the further development of the location in coordination with the foundation must also be identified and included.

Subsequently, an energy balance must be drawn up and the annual energy costs must be determined. Finally, a concept of measures with cost calculation must be drawn up.

c) Legal eligibility for approval

Geothermal energy generation or heat storage in former mines is subject to mining and water law. The framework conditions for the mining and water permit planning with regard to the limitation of the area of influence are to be developed.

Likewise, for the further necessary interventions in the World Heritage based on the developed energy, building and usage concepts, the coordination with the monument authorities must be conducted.

(d) Cost-effectiveness

For the overall concept, a detailed cost calculation and a financing concept must be developed in coordination with the foundation.

(e) Monitoringkonzept

Part of the feasibility study should also be a monitoring concept that can be used after the implementation of the measures or partial measures to document the success of the measures.

f) Project and scheduling

Finally, a time and project planning should be made for the project.

The content and goal of the award is the development of a feasibility study, which ultimately shows after the development, review and evaluation of scenarios, a concept how the Zollverein World Heritage Site can become climate-neutral, shows and coordinates the necessary measures, determines the costs and specifies a process and schedule.

The aim is to develop the solutions in such a way that they meet the requirements of a UNESCO World Heritage Site.

The preparation of the feasibility study must be carried out in close coordination with the client, the Zollverein Foundation. This is intended to ensure a strong feedback between the ideas of the contractor and the ideas of the client. For this purpose, regular reports (interim/work reports) and recorded coordination dates (as required, approximately every 2 to 4 weeks) must be kept.