The Nexus approach highlights the interrelationships between water, land use and food production, and energy, considered as fundamental elements for human development and well-being, from the point of view of sustainable development.
Each of the Nexus elements presents a broad problem-setting in itself, involving the participation of diverse actors at both the public and private levels, and generating interrelationships that are necessary to identify, both from the point of view of the dependence of one resource on another, as well as the impacts generated between each sector. In this context, the Nexus approach offers an opportunity for regional and national dialogue on public policies for the management of the interconnections between water, energy and food.
Within this framework, the present study describes the priority Nexus interrelationships that identified in Chile, with a special focus on the development and promotion of Solar Powered Irrigation Systems (SPIS).
In Chile, since 2008 the energy and agriculture sectors have encouraged the installation and promotion of photovoltaic pumping systems for irrigation. The metric that has been used to evaluate sectoral progress in these areas is the amount of irrigation surface area that is equipped year after year with these systems, from an agricultural point of view, and the installed power from the energetic perspective.
In recent years (2014 to date) there has been close work between the institutions involved in the promotion of SPIS, which are the Renewable Energy Division of the Ministry of Energy, the Agricultural Development Institute (INDAP), and the National Irrigation Commission (CNR).
With regard to water resources, in Chile water use rights are granted by the body in charge, the General Water Directorate (DGA) of the State, which carries out a registry management, mainly with the purpose of identifying extractions, but also for providing the necessary documentation that allows users to apply for competitive funds for irrigation projects. Some improvements in information flows have been identified, which are recommended to be put into practice in order to guarantee the sustainability of water resources.
Most photovoltaic pumping systems are associated with small-scale agriculture, which presents an integral challenge, demanding for the equal consideration of water use and availability and cost of energy being part of the same issue and both finally contributing to productivity. Most of the SPIS installed in Chile have been implemented with partial or total financing from public funds. Thus, different governmental programs considered SPIS in their types of solutions, mainly as a contribution to the productive development of certain areas or as an instrument of encouragement to improve the profitability of productive units, where the energy cost represents a significant factor within the total production costs.
The scenarios and projections of lower water availability, especially for irrigation, impose a need for intersectoral work, especially of the DGA, INDAP and CNR to advance towards a management platform that ensures the sustainability of resources, especially water, with a country view on the relationship between water, energy and food production. By not sharing information on the different programs, projects and plans of each of the sectors, the sustainability of the pumping and irrigation systems is weakened, and in some cases they are placed in an evident operational risk, given the changes that can occur in the levels of the aquifers, with respect to the conditions under which they were designed. Installing a large number of photovoltaic systems achieved its goal in terms of expanding the solutions with solar energy, but because of being focused only on the installation of equipment, in some cases this did not offer solutions to the real need of farmers. This is the reason for why the objective and
implementation of some programs should be reviewed, especially those that have a productive target and in practice are used as social aid.
The water resource presents the greatest challenges from the point of view of its availability, as well as the knowledge of the dynamics in local systems, so its study and characterization should be deepened, along with the promotion and installation of measurement systems, such as monitoring and follow-up of water levels in wells.
Training in the design, installation, operation and maintenance of SPIS and PV technology for irrigation managers, consultants, companies and equipment suppliers, as well as users, is a fundamental element that should be considered as part of a program of sustained work over time. The market today offers a great variety of technological solutions in the subject of solar pumping and irrigation, off-grid applications and grid-connected solar systems, which makes it necessary to deepen the levels of knowledge of the different actors.
Elaborate and present adequate strategies that allow the adaptability of production systems, reducing areas or replacing crops with less water intensive ones, in case of drought, are already elements that some farmers apply, as could be seen during the field visit to the Coquimbo Region. However, it is highly recommended to deepen these issues among all actors involved (Ministry of Agriculture, INDAP, INIA among others).