In addition to the secured regional sewage sludge utilisation, the high overall energy efficiency of the sew-age sludge incineration and the energy self-sufficient operation in Hanover-Lahe is an important project objective. By 2030, the energy service provider enercity wants to cover 80 percent of Hanover's heat supply with renewable energy. An important building block here is the construction of the Lahe waste incineration plant. The available heat from the mono-incineration of municipal sewage sludge will be fed into the district heating network of enercity AG and will thus be available to end consumers as climate-friendly and sustainable heat in Hanover. Once the plant is commissioned, 5,000 households will benefit from the heat generated by the sewage sludge incineration plant in the future.
The capacity of the state-of-the-art thermal sewage sludge utilisation plant is 30,000 t DS per year. This corresponds to a sewage sludge quantity of approx.130,000 t/a. The project is currently in the execution phase with the construction of the shell. The first step at the future site of the Lahe waste incineration plant was the concreting of the clean layer for the operating building and boiler house as well as the sludge reception bunker. Parallel to the preparatory construction work on site, the detailed engineering of the incineration plant was finalised as far as possible in close consultation with the planners of the structural engineering. This meant that the first installation parts for the plant steel structure and the anchor cage for the chimney could already be delivered to the construction site at the beginning of 2021. In the first quarter of 2021, the first concreting work for the floor slab and the base for the structural steel supports of the boiler house began. Prior to this, the tie-in of the column inserts and the anchor cage into the reinforcement bars was carried out. In the further course of the construction work, the stair tower and the mixing bunker for the delivered sewage sludge will be slipform concreted. The construction site is being prepared and set up in parallel for the upcoming (pre-)assembly work.
The production of the boiler, flue gas cleaning and turbine components will start in February 2021. Due to the limited clearance height to the construction site, not all plant components can be delivered to the construction site prefabricated. The pre-assembly of the large parts, such as the fluidised bed furnace (S2E fluidiser), will take place on site towards the end of the second quarter of 2021. In parallel, the assembly of the boiler house's plant steel structure is to start in coordination with the rough assembly of the plant technology. Finally, the construction measures are to be successfully completed by mid-2022. Subsequently, the commissioning of the sewage sludge mono-incineration plant in Hanover-Lahe will take place, so that the start of continuous regular operation will be at the beginning of 2023.