*Article* **Energy Recovery in Existing Water Networks: Towards Greater Sustainability**

### **Modesto Pérez-Sánchez 1, Francisco Javier Sánchez-Romero 2, Helena M. Ramos 3 and P. Amparo López-Jiménez 1,\***


**\*** Correspondence: palopez@upv.es; Tel.: +34-96-387700 (ext. 86106)

### Academic Editor: Arjen Y. Hoekstra Received:24October2016;Accepted: 3 February2017;Published:8February

**Abstract:** Analyses of possible synergies between energy recovery and water managemen<sup>t</sup> are essential for achieving sustainable improvements in the performance of irrigation water networks. Improving the energy efficiency of water systems by hydraulic energy recovery is becoming an inevitable trend for energy conservation, emissions reduction, and the increase of profit margins as well as for environmental requirements. This paper presents the state of the art of hydraulic energy generation in drinking and irrigation water networks through an extensive review and by analyzing the types of machinery installed, economic and environmental implications of large and small hydropower systems, and how hydropower can be applied in water distribution networks (drinking and irrigation) where energy recovery is not the main objective. Several proposed solutions of energy recovery by using hydraulic machines increase the added value of irrigation water networks, which is an open field that needs to be explored in the near future.

 2017

**Keywords:** irrigation water networks; water-energy nexus; renewable energy; sustainability and efficiency; hydropower solutions; water managemen<sup>t</sup>
