The water-energy nexus is the interdependency of water and energy: energy is needed for abstracting, storing, treating or disposing water but also for moving, heating and cooling water across industrial cycles, while water is also heavily used for the generation and transmission of energy. The nexus holds the potential to generate large-scale energy and water savings across sectors and reduce greenhouse gas emissions.
The energy use by water and wastewater infrastructure amounts to about 4% global electricity consumption and 3,5% in the European Union (IEA, 2016).
Water utilities can become energy neutral and even energy positive with existing technologies and low costs of investments.
The revision of the EU Urban Wastewater Treatment Directive (UWWTD) represents a key opportunity to deliver the transition in the sector. A good way forward would be introducing an energy efficiency target for wastewater treatment plants of a certain size, for example bigger than 10,000 in population equivalent (p.e.). Mandatory energy audits for wastewater treatment operators which include measuring water efficiency could also help advance the energy efficiency of the sector.
This would reinforce and echo new provisions on water and the energy savings obligations for public bodies, currently being negotiated by co-legislators in the Energy Efficiency Directive (EED) recast.
Digitalisation in the water sector is an important enabler towards energy neutrality. In wastewater treatment, existing digital solutions can achieve significant energy savings with limited investment needs (no civil engineering or hardware costs) within a short period of time. Intelligent pumps for wastewater management, for example, can save up to 70% energy per utility with 80% inventory reduction, thus lowering costs for utilities.
Saving water, saves energy and saving energy saves water. It is now time to advance energy efficiency and “RePower” the EU through the water-energy nexus!
by Tania Pentcheva
Senior Manager Government and Industry Relations
Xylem Inc.