Its commissioning creates the conditions for the decommissioning of Unit 1 of the Stöcken coal-fired power plant and paves the way for an early coal phase-out in Hanover. This week, the biomass-fired CHP plant fed green energy into the district heating network for the first time; the technical commissioning process is a multi-stage procedure.
The new power plant is Germany's first waste wood combustion plant to be operated with a large-scale heat pump using flue gas condensation. This combination enables nearly 100% fuel utilization – a technological milestone for climate-friendly heat supply.
In the future, the combined heat and power plant will supply up to 500,000 megawatt hours (MWh) of heat annually to Hanover and the neighboring Volkswagen Commercial Vehicles site. This will also benefit Hanover as a business location. The heat will be distributed via the state-of-the-art heat distribution hub also built on site. Compared to the coal-fired power plant, the biomass-fired combined heat and power plant will reduce CO₂ emissions by approximately 300,000 tons per year.
“Enercity stands for holistic solutions when it comes to the energy and heat transition. The biomass-fired combined heat and power plant is an excellent example of a green heat transition and integrated collaboration – it was planned and built with the combined expertise of the enercity Group together with our subsidiary Danpower. That's what makes enercity special – we offer everything from a single source, from planning to implementation. This is how we drive the energy and heat transition forward,” says Enercity CEO Aurélie Alemany .
The biomass power plant uses exclusively non-recyclable waste wood. This means that this wood can only be used for thermal energy recovery. The waste wood comes from the surrounding area within a radius of approximately 150 kilometers. In this way, enercity strengthens regional supply chains and contributes to the circular economy. With the commissioning of the biomass power plant, the share of climate-neutral district heating in Hanover will then rise to up to 50 percent. This will make the heat supply increasingly independent of fossil fuel imports and more price-stable in the long term.
Enercity is investing around €195 million in the new combined heat and power plant. It is part of a comprehensive investment program by enercity to gradually and consistently decarbonize district heating in Hanover. Enercity is deliberately foregoing the interim solution of natural gas.
This will result in a total of 14 new climate-neutral generation facilities – including large-scale heat pumps, geothermal energy, and biomethane projects. To ensure that as many people as possible can benefit from district heating, the pipeline network will be expanded from its current length of approximately 360 kilometers to around 550 kilometers. In the target scenario, the number of buildings supplied will increase to around 18,000 – five times the current number. By 2040, enercity will have invested around €1.5 billion in network expansion and replacement facilities for Hanover's green district heating.
The heart of the new power plant is a grate boiler that dries, ignites, and completely combusts the waste wood in several stages. A multi-stage flue gas cleaning system ensures that emission limits are significantly undercut. The integrated large-scale heat pump utilizes the waste heat from the flue gas, raises its temperature to district heating levels, and thus increases the overall efficiency of the plant.
PHOTO: Belit Onay, Mayor of Hanover, Aurélie Alemany, CEO of Enercity, Christian Meyer, Lower Saxony Minister for Environment, Energy and Climate Protection and Steffen Reiche, Member of the Board for VW Commerical Vehicles for Production and Logistics.
