Towards a climate neutral water cycle

Waternet, the first water cycle company in the Netherlands, is responsible for drinking water treatment and distribution, wastewater collection and treatment, and water system management and control in and around Amsterdam. Waternet has the ambition to become climate neutral in 2020. To realise this ambition, measures are required to compensate for the emission of 53,000 t CO₂-eq/year. Energy recovery from the water cycle looks very promising. From wastewater, ground water, surface water and drinking water, all elements of the water cycle, renewable energy can be recovered. This can be thermal energy and chemical energy. First calculations reveal that energy recovery from the water cycle in and around Amsterdam can contribute to a total reduction in greenhouse gas emissions up to 74,900 t CO₂-eq/year. The challenge for the coming years is to choose robust combinations of all the possibilities to fulfil the energy demand at any time. Only then can the use of fossil fuel be abandoned and the target of becoming climate neutral in 2020 be reached.