Water distribution and heat networks use sensors for monitoring purposes. And these sensors need energy. In research conducted under the InDeal project to improve water network efficiency, Leti, a CEA Tech institute, designed and dimensioned a micro-hydro turbine capable of harvesting the energy from water running through pipes to power pressure and temperature sensors and flow meters, effectively making the devices self-powering. The technology could replace the batteries or electrical wiring currently required to power the devices, reducing maintenance costs in the process.

The researchers developed systems compatible with the dimensions and robustness (pressure, temperature, moisture) requirements of existing water distribution networks. They designed and modelled a micro turbine measuring several centimeters in diameter, carefully selecting the materials to be used. They then built a prototype whose size could then be adapted to the target requirements.

Testing was completed in the lab, and then in real-world conditions (on the Montpellier water distribution network) over a period of four months. The turbine proved reliable and numerous benefits were observed. First, the turbine generated enough electricity to power the sensors (10 mW to 100 mW), shutting down when flow rates fell too low and automatically restarting when flow rates permitted.

Leti will now test the turbine over a longer period and find partners for further development and industrial scale-up.