Assessing the potential of solar energy in pressurized irrigation networks. The case of Bembézar MI irrigation district (Spain)

Abstract

IntroductionIn the interest of sustainable development and the minimization of climate change impacts, national and international policies are prioritizing the improvement in the use of the natural resources. Water is an essential and limiting resource for private use, industry and agriculture that requires large amounts of energy for AbstractThe high energy requirements and the rising costs highlight the need to reduce the energy dependence of the irrigation sector. Alternative management strategies have been developed to reduce the energy consumption of the irrigated areas and to improve the efficiency in the water and energy use. In addition, the renewable energy sources are starting to be considered as an alternative to reduce energy costs with smaller environmental impacts. In this work, a new methodology, that combines sectoring as energy saving measure and solar energy, is developed. Thus, it reduces the energy requirements and the dependence on conventional energy resources. This methodology is applied to the irrigation district of Bembézar Margen Izquierda (Córdoba, Spain). The results show that organizing the network in two irrigation sectors, annual potential energy savings of 30.8% were achieved. Therefore, this measure reduces the annual energy bill in 30.4% without major investments. Then, a 2.1 MW photovoltaic would supply energy to the sector with higher energy consumption. However, conventional energy would be required (with an annual cost of € 33.6 ha -1 ) when solar energy is not available or it is not enough to supply the demanded flows. Both measures together would reduce the energy costs in 71.7% and the greenhouse gases emissions in 70.5%. The total investment would be Me 2.8 but with a payback period of 8 years. At present, solar energy is a technically and economically viable alternative, which offers both economic and environmental benefits.Additional key words: water management; renewable energy; solar PV; greenhouse gas emissions.* Corresponding author: g22carco@uco.es Received: 20-11-13. Accepted: 20-06-14.Abbreviations used: AC (alternating current); BMI (Bembézar Margen Izquierda); DC (direct current); GHG (greenhouse gases); IPS (intelligent power system), IRR (internal rate of return); MPPT (maximum power point tracker); NPV (net present value); OHPM (open hydrant probability matrix); PV (photovoltaic); RIS (annual relative irrigation supply); S1 (Sector 1); S2 (Sector 2); WEBSO (water and energy based sectoring operation). Glossary: E [daily energy demanded by the pumping station in the peak demand month (kWh)]; EF [emissions conversion factor (kg CO 2 eq kWh -1 )]; E mjl X P [energy demand at the pumping station in month (m), management scenario (j) and operating sector (l) (kWh)]; E T [annual energy consumption in the pumping station (kWh)]; G [global irradiation on the PV array plane for the peak energy demand day (kWh m

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“…However, optimal management of irrigation networks does not avoid the dependence of irrigation agriculture on fluctuations in energy prices. Therefore, in recent years, the reduction of electricity production costs from renewable energy sources (wind, solar photovoltaic and micro hydropower) is facilitating their incorporation into the irrigation sector [64,95,96]. Since the generation of energy depends on suitable weather conditions (sufficient wind or solar radiation for pumping), irrigation must be scheduled around the availability of renewably sourced energy [64].…”

Sensitivity of Agricultural Development to Water-Related Drivers: The Case of Andalusia (Spain)

“…On-farm-energy solar generation has proven to be a suitable alternative to reduce energy costs in irrigation. For instance, Carrillo-Cobo et al [89] estimated a reduction in energy costs of 60% in the Bembézar MI irrigation district (Andalusia) driven by the implementation of photovoltaic energy. Additionally, the recent change in energy legislation (i.e., the Royal Decree 244/2019, 5 April, that specifies the arrangements for administrative, technical and economic conditions for electric energy self-consumption), which eliminates taxes to electric energy self-consumption in Spain, might boost the expansion of solar energy in agriculture, with implications for irrigation costs that will need to be further assessed under tailored water cost scenarios.…”

A Review on Renewable Energy Systems for Irrigation in Arid and Semi-Arid Regions

“…Carrillo-Cobo et al [55] evaluating the potential of solar energy in pressurized irrigation, with a case study in the district of Bembézar MI (Spain), developed a new methodology that combined sectorization as a measure of energy and solar energy saving, thus reducing energy requirements and dependence on conventional energy resources. The results showed that this measure could reduce the annual energy bill by 30.4% without large investments.…”