The water-energy nexus

By Monica Frassoni, President, European Alliance to Save Energy (EU-ASE), (pictured)
Spring 2023

Connecting water saving, energy efficiency and the reduction of emissions.

Monica Frassoni, President, European Alliance to Save Energy (EU-ASE)Water requires energy. Each time we abstract, move, clean, heat and cool water we need energy. And when we generate energy, we need water. Water and energy are probably two of the most essential, interlinked, and precious resources in our daily lives. In our current climate and energy crisis unleashing the potential of the water-energy nexus will drive substantial water and energy savings, reducing emissions and increase the competitiveness of European industry. The great thing is that we already have the technologies and solutions to simultaneously save water and energy.

We can, for example, reduce the energy needs and optimise the consumption of wastewater treatment plants deploying digital tools such as artificial intelligence, cloud solutions, advanced software and connected sensors. Data transparency and advanced data analytics allow for a holistic management of wastewater collection and treatment systems resulting in improved treatment effectiveness, reduced failure of infrastructure and leakages, limited overflows of the sewer system and reduced capital investment requirements into unnecessary new infrastructure development and energy consumption.

Climate change is the cause of more and more extreme precipitations. Impervious surfaces in urban areas reduces water infiltration putting enormous pressure on the urban wastewater infrastructure and increasing energy consumption of treatment facilities. In this context, nature-based solutions for decentralised stormwater management such as green roofs and green spaces in urban areas promote natural water retention and detention reducing runoff, sewage overflow and the energy cost related to the treatment of increasingly big quantity of rainwater. These are mature and proven technologies that deliver energy savings.

Other areas where the nexus holds the potential to generate large-scale energy and water savings is manufacturing, energy and agriculture sector. Water is critical to industrial production. There are major economic sectors ranging from beverage and food processing to automotive, farming, chemical and energy production in which water is indispensable. With existing technologies, we can address the pressing issue of water scarcity promoting water reuse techniques. Again, digitalisation plays an important role to ensure that water and energy efficiencies help production processes and increase competitiveness thanks to costs reductions while help mitigating climate change.

A strong policy framework is needed to incentivise water and energy efficiency and enable the deployment at scale of these solutions. The water-energy nexus should be better reflected in legislation, and lawmakers should fully consider the benefits stemming from water efficiency as a key driver to delivering energy savings. At the European Alliance to Save Energy we have pioneered the policy debate around this topic and several policy developments are currently underway.

The revision of the EU's Energy Efficiency Directive, currently in its last phase of negotiations, will hopefully acknowledge the water-energy nexus and encourage industry to monitor water and energy consumption and assess water efficiency opportunities as part of their energy audits. The legislators could have been much more ambitious but the Directive is a step in the right direction.

The revision of the Urban Waste Water Treatment directive is following its ordinary legislative process. The European Commission proposal has addressed the issue. More will have to be done to ensure that the application of the ‘Energy Efficiency First' principle is the first step on the path to energy neutrality of waste water treatment plants by 2040. Increased energy efficiency can drastically reduce the facilities’ energy needs and accelerating the integration of renewable energy sources. Moreover, treated wastewater carries a valuable source of renewable energy in the form of waste heat that can be recovered. The proposal introduces also the obligation to establish locally integrated urban wastewater management plans to tackle urban runoff and storm water overflow suggesting prioritising preventive measures promoting natural water retention, and measures increasing green spaces over the creation of new infrastructures. There are certainly synergies to exploit with the recent proposal of a Nature Restoration law that proposes mandatory urban green targets for European cities.

The revision of the Industrial Emission Directive is also ongoing, and several inputs received from stakeholders call for the legislator to systematically consider water and energy savings as a key driver for emission reductions.

Technological solutions already exist, they are tried and tested and can make a profound difference to solve water and energy challenges and to make long-lasting impacts. We need to seize this moment to promote dialogue and reflection around the water-energy nexus. It is time for Europe to have a more systemic and holistic approach and design a long waited European Water Strategy that aggregates stakeholders and set goals and direction for the next years.