Solutions to optimize the use of solar energy in irrigation communities

Solutions to optimize the use of solar energy in irrigation communities
by Hugo Ritmico
Madrid, Spain (SPX) Jul 08, 2024

Irrigation communities are striving to make their activities more sustainable both environmentally and economically. Energy self-sufficiency is emerging as a promising solution for the future of agriculture. In 2019, the Lower Guadalquivir Valley Irrigation Community, which spans nearly 19,000 hectares and serves over 2,000 irrigators, began using solar energy with a 6-megawatt photovoltaic plant-the largest of its kind among Spanish irrigation systems. This initiative has positioned the community as a pioneer and research hub for transitioning to a sustainable irrigation model.

Recently, the community has partnered with the Maria de Maeztu Unit of Excellence's Hydraulics and Irrigation research group and the University of Cordoba's Department of Agronomy (DAUCO). Together, they have proposed strategies to maximize the use of solar energy, prevent energy waste, and reduce reliance on external power sources.

"The researchers responsible for the study, Maaike van de Loo, Emilio Camacho and Juan Antonio Rodriguez, explain that more solar energy is currently produced than is used, generating a surplus of around 50%, while a secondary source is necessary to meet energy needs when solar energy is not being produced; at night, for example." Their study, published in the journal Renewable Energy, explores two solutions to optimize energy use and minimize waste.

The first solution involves changing irrigation schedules to align with daylight hours when solar energy is available, moving away from nighttime irrigation. Traditionally, the Lower Valley Community favored nighttime irrigation due to lower energy costs and reduced water evaporation. However, the cost reduction from the photovoltaic plant and the efficiency of drip irrigation, which cuts water use by up to 60%, provide compelling reasons for irrigators to adapt.

The proposed strategy shifts from 24-hour on-demand irrigation to an 8-12 hour window during sunlight hours, significantly increasing the utilization of solar energy to over 90%. Although an additional energy source would still be required to supplement solar power, especially given weather variability, the ample sunshine in Andalusia-over 3,000 hours annually-would substantially decrease dependence on external energy, enhancing both economic and environmental sustainability.

The second solution focuses on the economic aspect: selling surplus energy, a practice already in place in the Lower Valley Community. However, increased solar energy production at the national and European levels has driven prices down, impacting profitability.

The study concludes that while there is no perfect solution for fully exploiting solar energy, it remains a valuable resource. The researchers believe that ongoing research and the experience of the Lower Valley Irrigation Community will guide the future of irrigation, balancing environmental protection with economic viability by leveraging the region's solar potential.

Research Report:Defining the optimization strategy for solar energy use in large water distribution networks: A case study from the Valle Inferior irrigation system, Spain