SIAAP is embarking on an ambitious trajectory towards energy neutrality for its sanitation activities. This approach combines energy sobriety, optimization of industrial processes, and valorization of resources from wastewater, thereby contributing to the public service's energy sovereignty and carbon footprint control.
This strategy aligns with the objectives of the new European Directive on Urban Wastewater Treatment (DERU2), which sets an energy neutrality target for sanitation by 2045. SIAAP, a pioneer in green energy production since 1940, is maintaining its course with its methanation units.
Currently, 46% of SIAAP's energy needs are met by energy produced at its plants, a level already compliant with European objectives for 2035. The organization consumes approximately 1.1 TWh per year and produces nearly 590 GWh of valorized biogas, equivalent to the annual electricity consumption of about 270,000 inhabitants, such as the city of Bordeaux.
The sites of Seine Aval, Seine Valenton, and Seine Centre have been certified ISO 50001 since 2024, 2022, and 2026 respectively. SIAAP plans for a global certification in the medium term.
Energy performance relies on two levers: controlling consumption, which accounts for 15% of operating costs (600 GWh/year), and valorizing energy resources. Improving equipment efficiency, modernizing facilities, particularly at Seine Aval, and recovering heat from incineration furnaces and wastewater are priority areas.
In total, 355 GWh per year of additional energy resources are mobilizable, notably through the evolution of the Dehydrated Sludge Production Unit (UPBD) at the Seine Aval plant. Planned investments will progressively raise the energy neutrality level to over 56%, and then to 70% by 2040-2045.
Wastewater treatment plants are becoming transformation hubs serving the decarbonization of territories. SIAAP already contributes to this dynamic by injecting its surplus biogas into the GRDF network. Projects for sharing excess heat are also emerging in Clichy and Colombes to supply urban heating networks with green energy.
With energy neutrality already close to 50% and a credible trajectory towards the DERU2 objectives, SIAAP confirms its commitment to making energy a lever for environmental performance and economic resilience for the Île-de-France territories.
