Managing the water-energy nexus

Today, wastewater collection and treatment account for a quarter of the water sector’s total electricity consumption. According to IEA, this demand is expected to rise by more than 60 percent by 2040 as more wastewater is being collected and treated. However, the organic content in the wastewater can also be used to produce energy and thereby contribute to covering both the water sector’s and the rest of the society’s energy needs.

In order to reduce its dependency on traditional sources of energy, water utilities need to be highly energy efficient throughout the water cycle, utilise synergies with sustainable energy sources like solar and wind and recover energy from wastewater treatment plants. In Denmark, water utilities are required to benchmark their performance, which makes it possible to establish specific targets for energy consumption, energy efficiency and energy recovery.

In Denmark – as in many other countries – wastewater treatment plants are moving from being heavy consumers of energy to becoming energy and resource recovery facilities. By utilising the biogas potential – along with energy saving technology – several plants are now producing more energy than they consume. This has led the most ambitious Danish water utilities to set goals of achieving a carbon-neutral water sector across the entire water cycle within a few years. The Danish water sector as a whole has the ambition of becoming energy and climate neutral by 2030.

Connect with us: Tanya Gottlieb Jacobsen, Deputy Director and Head of Water & Climate Change Adaptation, tja@stateofgreen.com