**5. Conclusions**

In this research, a methodology for quantifying the potential recovered energy for an average year in an irrigation network has been presented. Even nowadays, some irrigation networks do not have flowmeters. In these cases, a flow estimation method must be implemented: the flow is assigned to pipes along time depending on registered volumes, irrigation trends, and consumption patterns.

Once flows are known, the EPANET toolkit is used for estimating pressures in different scenarios along the year in order to determine pressure and energy balance for each point. Hence, it is possible to discriminate the energy needed for irrigation, friction head losses, non-recoverable energy, and potentially recoverable energy in any line or hydrant in a network.

The method was demonstrated as applied to a real case. Considering consumption records from 2003 to 2014, an irrigation network in Valencia (Spain) has been analyzed in order to determine the dissipated and recoverable energy, observing that the energy footprint achieves maximum values of 2.85 kWh/m3, being 79.7% of time under 0.3 kWh/m3. The potential recoverable energy, instant power, recovering coefficients relating total with recoverable energy and frequency histogram of power are studied for any irrigation point, hydrant or line.

The maximum estimated potential recoverable energy sums to 188.23 MWh/year considering all the consumption points, and 178.1 MWh/year considering all the hydrants. If only one turbine were to be installed, the more convenient location is line 38, with a potential recovery of 89.99 MWh/year.

Future works should be undertaken to analyze the performance of real turbines in lines in order to propose a method to optimize the selection of turbines and the technical and economic involvements of such installations in different irrigation networks.

**Acknowledgments:** This paper has been possible with the free collaboration of the "Comunidad de Regantes Virgen de Gracia". No additional funds have been received for this research. Authors thank the reviewers for their valuable comments, which have greatly contributed in the improvement of the document.

**Author Contributions:** All the authors have participated in any step of this research. Particularly a brief description is attached: The author Helena M. Ramos has contributed supervising the state of the art description, flow assignation and energy implications of the present study. The author Francisco Javier Sánchez-Romero has been involved in the conception of the methodology for flow assignation and computational programming for EPANET Toolkit. The author Modesto Pérez-Sánchez has analyzed the flow data for proposing the final flow distribution, has implemented the data for EPANET Toolkit and analyzed the results for energy determination. The author P. Amparo López-Jiménez has supervised the whole research and document and has been involved in final energy analysis of results and conclusions.

**Conflicts of Interest:** The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.
