The Lübeck Utilities Energy GmbH (SWL) has been developing a transformation plan since November 2023 with service providers according to the Federal Funding for Efficient Heating Networks (BEW) for the district heating networks Vorwerk and St. Lorenz, which are to be connected in the future. The current status of the transformer plan indicates the use of wastewater heat from the Central Treatment Plant Lübeck (ZKW) as a central heat source for the connected district heating network. To utilize the wastewater heat in the connected district heating network, a part stream will be drawn from the treated wastewater flow of the ZKW and fed into a heat pump installation. The cooled water will be returned to the outlet of the Central Treatment Plant before being discharged into the Trave.

LOT-0001
Planning Wastewater Heat Pump Central Treatment Plant.
Lot 1: Between February 2026 and September 2026, the HOAI planning phases 1 - 4 for the wastewater heat pump, including connection to the wastewater stream, are to be carried out. Lot 2: Between July 2026 and December 2026, the HOAI planning phases 1 - 4 for the object and external site planning, including foundation lines, as well as the structural planning of the building and the foundation of the buffer tank, are to be conducted. Bids for one or both lots are permitted. If a bidder submits a bid for both lots, a combination advantage of 10 points will be granted to the overall evaluation. The bonus serves to consider efficiency gains, project coordination, and interface reduction.

LOT-0002
Object and External Site Planning as well as Structural Planning for the Building of the Wastewater Heat Pump.
Lot 1: Between February 2026 and September 2026, the HOAI planning phases 1 - 4 for the wastewater heat pump, including connection to the wastewater stream, are to be carried out. Lot 2: Between July 2026 and December 2026, the HOAI planning phases 1 - 4 for the object and external site planning, including foundation lines, as well as the structural planning of the building and the foundation of the buffer tank, are to be conducted. Bids for one or both lots are permitted. If a bidder submits a bid for both lots, a combination advantage of 10 points will be granted to the overall evaluation. The bonus serves to consider efficiency gains, project coordination, and interface reduction.