In September 2022, the sewerage association Schwarzachgruppe launched its energy-intelligent wastewater treatment plant in Schwarzenbruck, Germany. The wastewater-treatment plant is an environmental-innovation showcase project, which automatically balances energy-consumption and production so that an external power supply is required only rarely or when needed. Thanks to this energy-intelligent concept, it is estimated that the plant can save about 300 tons CO₂ per year, per
ABB, which notes that its energy-management/optimization solution OPTIMAX is at the heart of this innovative project, enabling energy efficiency potentials to be exploited and existing energy-generation/storage options to be networked, controlled and optimized.
These include a hydroelectric power plant in the wastewater-treatment plant outlet, photovoltaic solar panels, two combined heat and power plants using sewage gas, electricity storage in batteries, sewage-gas storage, heat storage (hot-water storage) and the coupling of the various storage units for the continuous provision of energy (thermal or electrical as required).
In addition, the wastewater-treatment plant operates in a grid-serving manner. This means that some assets at the wastewater treatment plant can be controlled via the OPTIMAX energy-management system, according to ABB. In the event of an oversupply of electricity, for example, the battery-storage system is charged for use during low production. The solution is able to calculate the optimum usage of the storages based on load and production forecasts.
To be able to monitor, control, regulate and optimize such a complex energy system in an energy-efficient way requires an intelligent energy-management and optimization system such as OPTIMAX, according to ABB, which claims an energy saving of 100% of the previous electricity consumption required from the grid.
The integration of the wastewater-treatment plant into the grid-serving operation is an essential part of the project, per the partners.