For the new development area "Weiberdell-Teilbereich II" Nastätten, an ecological and sustainable heat supply in the form of a supply contracting system (heat contracting) is to be realized. The heat generation must be 100% renewable.

a. Principles of the procedure

For the new development area "Weiberdell - Subarea II" Nastätten, an ecological and sustainable heat supply is to be realized. As part of a feasibility study on the energy supply of the planned new development area, the essential parameters for energy consumption have already been defined and the investigation of various energy supply variants has been completed. The city of Nastätten would like to implement a cold local heating supply. In the feasibility study, a geothermal probe field as a heat source for the passive, cold local heating network is economically better than a combination of an ice energy storage system with an energy fence and a geothermal probe field. The cold local heating is to be used as an energy-efficient heat source for the heat pumps in the connected buildings. The heat pumps are to be supplied by the operator/installer. On-site construction by private builders is not planned, not even as an option. For the implementation of the cold local heating solution in the construction area, the city of Nastätten is looking for an investor and operator. The client is the city of Nastätten. The duration of the contract is to be 10 years with the option of an extension of 5 years.

b. Description of procurement

The feasibility study together with the functional specification is attached to the tender documents.

Scope of services: The investor and operator implements a passive, cold local heating network with a geothermal probe field. It is permitted in the procedure that the technical components of the cold local heating supply are to be used as an ancillary offer in combination with ice energy storage, if necessary with an energy fence. The specific planning and the specific plant design in the Contractor's area of responsibility can be found in the service description under Chapter 3. The performance data given below as well as the parameters described must be checked by the bidder in any case. As part of the investment and operational measures, the contractor undertakes:

• Complete planning, obtaining permits, financing and acquisition of subsidies as well as delivery.

• Construction, operation, maintenance and servicing of the geothermal probe field, if necessary an ice energy storage system

• Construction, operation, maintenance and servicing of the cold local heating network

• Measurements as well as remote monitoring (at least according to the requirements of the permit)

c. Interfaces and billing

After construction, the ownership boundaries are: The bidder owns the following: • Geothermal probe field

• Cold local heating network: The technical interface of the heat supply is located behind the shut-off valve (ball valve) after the entry of the house connection into the buildings. For billing the heat source provided for the decentralised heat pumps in the new buildings, either quantitative billing or a flat rate is possible. The billing method must be defined in the price information

The purpose of the feasibility study is only to assess the economic advantage of the proposed project.

d. Schedule

The entire project of a cold local heating supply for the new development area in Nastätten is shown in the schedule. The operator of the passive, cold local heating network is responsible for further planning, applying for subsidies, implementing and contracting the cold local heating system. A major milestone is that the daycare center in the new development area will require a heat supply in the first quarter of 2024, which may have to be temporarily solved.