Use of PV can reduce diesel consumption in energy-intensive cultivation in southern Europe, writes Pilar Sánchez Molina from PV Magazine.
Italian, Spanish and Portuguese scientists have published a study about energy consumption and the environmental footprint of the use of solar-hybrid irrigation systems in olive plantations in Portugal and Morocco.
A research article by Italian, Spanish and Portuguese scientists, published in the magazine Elsevier and entitled “Energy and environmental performances of hybrid photovoltaic irrigation systems in Mediterranean intensive and super-intensive olive orchards”, analyzes the energy and environmental expenditure of two hybrid photovoltaic irrigation systems large-scale commercial power plants (HPVIS) installed in intensive and super-intensive Mediterranean olive groves.
In the last decades, intensive or super-intensive olive plantations have seen spectacular growth. Although it is a traditionally rain fed crop, maintained in the plantations where the most valued oil in the world is produced by the EVOOWR (the World Ranking of Extra Virgin Olive Oils), there are places where, due to the price increase of the oil produced with rain-fed olives, around 18% of the total area is devoted to irrigated olive cultivation.
This conversion increases the production of olives considerably, as well as that of the energy that is needed for this cultivation.
The data of the hybrid photovoltaic solutions are compared the electrical grid and with diesel generators, while a comparison of the environmental benefits of HPVIS with conventional energy sources is also established.
Energy consumption and the environmental footprint were evaluated through the recovery times of energy and carbon (EPBT and CPBT). The results show EPBT of 1.98 and 4.58 years in Morocco and a CPBT of 1.86 and 9.16 years for HPVIS in Portugal. In addition, HPVIS achieved low emission rates, corresponding to 48 and 103 g of CO2e per kWh generated.
The consumption of grid electricity and diesel fuel was also analyzed, before and after the implementation of the HPVIS systems. The results obtained show a saving of fossil energy of 67% for the Moroccan farm and 41% for the Portuguese.
According to the paper, hybridization is the only cost-effective alternative for photovoltaic applications when a plantation requires irrigation in hours when the sun does not shine. Therefore, analyzing and comparing the environmental impact of photovoltaic and diesel hybridization can be very useful for the design and improvement of this type of plantations. Finally, the application of HPVIS to olive groves and the comparison of environmental benefits with other conventional energy sources and irrigation techniques also represents a new valuable contribution to the existing literature in the field.
Irrigation with solar is widespread in Latin American countries. In an international forum held in Rome in April, the Food and Agriculture Organization of the United Nations presented a World Report in which it encouraged the adoption of solar irrigation systems. “The rapid expansion of increasingly affordable solar energy irrigation offers viable solutions that span the links between water, energy and food, offering a great opportunity for small-scale farmers to improve their livelihoods, economic prosperity and security”said Deputy Director General of FAO, Helena Semedo.
FAO also presented online tools on solar-powered irrigation systems, developed jointly with the German International Cooperation Agency (GIZ) and designed to provide practical guidance to end users, policy makers and donors.
Pilar Sánchez Molina
Pilar worked as managing editor for an international solar magazine, in addition to editing books, primarily in the fields of literature and art.
She joined pv magazine in May 2017, where she manages the Spanish newsletter and website and helps write and edit articles for the daily news section in Latin America.
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