The nexus of water and energy, two vital resources, is becoming critical in cities due to demographic movements, economic growth and an inexorable increase in demand. Water scarcity and the need for low-carbon solutions make it a challenge to deliver urban water services without increasing their impact on the environment.
Ahead of World Cities Day on 31 October, whose theme this year is 'Changing the world: innovations and better life for future generations', we take a look at a pioneering LIFE project looking to use urban water networks as a source of renewable energy. LIFE NEXUS wants to show the potential of micro-hydropower systems for recovering untapped energy, deriving from abundant pressure (water head) or kinetic energy (water flow), in European water networks.
The project will install a prototype at the Porma drinking water treatment plant in the Spanish city of León, integrating Pump-as-Turbine (PaT) technology with energy storage. When fully operational next year, this will supply the plant’s total annual energy demand. Another prototype, an intelligent monitoring and management platform, will control the PaT’s operation and how the energy generated is used. The pilot should be ready to launch by the end of 2020.
No systematic assessment exists of hydropower’s potential to produce ‘green’ electricity in Europe. LIFE NEXUS is bridging this data gap with the first European inventory of existing and potential locations for energy recovery. This already contains 75 locations in 10 different European countries, with the information georeferenced and available through a web platform.
The project is building a broad community of stakeholders linked to water services to help identify new locations for its inventory, via a simple online survey. The inventory will feature industrial locations and irrigation areas, as well as urban sites, to promote the project’s transfer.
LIFE NEXUS brings together partners from Spain, Poland and Lithuania, a valuable cross-border network. “Urban water management is highly energy intensive. Harnessing the potential energy within these systems is of great importance,” says Raquel López of CARTIF, the Spanish research and technology centre coordinating the project.
“Evaluating this potential at European level, something never done before, is ambitious. Our partners in Lithuania and Poland are crucial due to their previous experience with the STREAM MAP project, which focused on the methodologies and tools for better water and hydropower planning, applied to European rivers,” she adds.
“Immediately afterwards, our Lithuanian partner was involved in the RESTOR Hydro project, which produced a GIS map with locations of historic water mills and small weirs where restoration or initiation of small hydro activity could be considered. Quite similar methodology is applied now when documenting the findings of the LIFE NEXUS project.”
Spreading the word
Data obtained from the LIFE NEXUS pilot plant’s operation will be integrated with the project’s inventory to provide a clear picture of the potential for energy recovery in European cities, and the technical and economic feasibility of new mini-hydraulic projects assessed. LIFE NEXUS will produce replication studies for a number of stakeholders contributing to the inventory, to ensure maximum replicability and transfer of its results.
Image: "Water" by The-World-According-To-Pleiades is licensed under CC0 1.0