Research Paper Energy efficiency of pressurised irrigation networks managed on-demand and under a rotation schedule M.A. Moreno*, J.I. Co ´rcoles, J.M. Tarjuelo, J.F. Ortega Regional Center of Water Research, Universidad de Castilla La Mancha, Ctra. de las Pen ˜as, km 3,2, 02071, Albacete, Spain article info Article history: Received 3 June 2010 Received in revised form 7 September 2010 Accepted 29 September 2010 Collective irrigation networks are often sized to work on-demand. However, the high investment cost of this kind of infrastructure has lead to selection of scheduled rotational management, which reduces the investment cost. The objectives of this study were 1) to compare the operational costs of 4 irrigation networks using energy-based performance indicators, two managed to work on-demand and two under rotational management, and 2) to determine the most appropriate pumping station management using tools developed by the authors. The indicators used were calculated using data obtained in Spain during the 2007 and 2008 irrigation seasons. To obtain these indicators, hydraulic and energy simulation models were used. Results showed that the irrigation networks working under rotational management were more susceptible to inefficient use than on-demand irriga- tion networks. However, if the pumping stations in rotation scheduled irrigation networks were properly managed, greater energy efficiency can be obtained than in on-demand irrigation networks. Rotation schedule irrigation networks are more susceptible to ineffi- cient management because of the lack of available management tools to select the configurations of open hydrants and choose the proper pumping head for each of these configurations. In the case studies examined, using the tools developed by the authors, improvements in energy efficiency achieved were between 3.5 and 24.9%, with higher potentials for improving energy efficiency occurring with irrigation networks managed to operate under a rotation schedule. ª 2010 IAgrE. Published by Elsevier Ltd. All rights reserved. 1. Introduction On-demand irrigation networks are seen as the solution to the classic rotation schedule network problem, where water use efficiency is low because of the lack of flexibility in the schedule and the availability of water. Farmers tended to irrigate as much as possible when water is available, which leads to water being wasted and irrigation schedules not being followed. Theoretically, on-demand irrigation networks should make the exact quantity of water available at the correct time, since farmers can irrigate at will. Although on-demand irrigation represents a step forward in flexibility for water users, it can imply a significant expenditure in energy (Rodriguez Diaz, Lopez Luque, Carrillo Cobo, Montesinos, & Camacho Poyato, 2009). In addition, on-demand irrigation networks can result in inefficient water use if farmers do not perform adequate irrigation scheduling, particularly when they need the help of the irrigation advisory services (Ortega, De Juan, & Tarjuelo, 2005). * Corresponding author. Tel.: þ34 967599200x2586; fax: þ34 967599269. E-mail addresses: MiguelAngel.Moreno@uclm.es (M.A. Moreno), JuanIngnacio.Corcoles@uclm.es (J.I. Co ´ rcoles). Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/issn/15375110 biosystems engineering 107 (2010) 349 e363 1537-5110/$ e see front matter ª 2010 IAgrE. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.biosystemseng.2010.09.009