No abstract

Chile has set itself to achieve Greenhouse Gas emission neutrality, with at least 70% of electricity coming from renewable energy sources by 2050. To this end, institutional and regulatory frameworks have been improved, resulting in significant progress in medium and large-scale projects. However, solar energy production at residential level and its surplus injection to all distribution networks has been very limited. This paper analyzes the evolution of the regulatory energy policies in Chile in order to contrast it with an economic evaluation of residential projects. The analysis focuses on the city of Arica, one of the highest potential regions in terms of solar energy within the country. There, a particularly low penetration of residential solar energy usage has been observed. Based on the current situation, projections are made for Arica in 2050, through the identification of barriers and opportunities on a residential scale development. According to some recommendations, there is the need to design policies that take into account the particular characteristics of each region within the country.

The natural potential of Chile—solar energy and 8 km of coastline—make the implementation of small-scale reverse osmosis desalination plants (RODPs) in coastal areas energetically supported with photovoltaic systems (PVs) feasible. This work considers a survey of the plants in Chile. As a demonstration of a RODP, a technical/economic evaluation is carried out, analyzing four possible cases in which different energy configurations are proposed: electric grid, diesel generator, and photovoltaic systems, without or with batteries. Finally, the challenges and opportunities of these plants are presented. The results obtained indicate that there are 39 plants in operation, which produce an average permeate water flow of Qp 1715 m3d−1. Solar Explorer, and Homer Pro software are used for a plant that generates 8 m3day−1 of permeate water, resulting in the conclusion that Case 3 is the most economically viable, as it has a useful life of 20 years and will have an annual solar contribution of more than 65%. The levelized cost of water production is 0.56 USDm−3 (RODP/PV) and 0.02 USDkW−1h−1 was obtained for the LCOE. Finally, this case contributes to the mitigation of climate change.

In the region of Arica and Parinacota, Chile (South America), concerned about the environment, the use of brine from a reverse osmosis plant was considered as irrigation water, which is generally discharged into the sea, sewers, or nearby rivers. In this sense, the integrated management of this waste was studied under the 3 principles and 11 strategies of the circular economy, for which it will be used to produce halophilic fodder (Atriplex nummularia), supporting the sustainability of livestock farmers in the sector. As for the results, it was estimated that with 86,400 Lh-1 in 20 days of brine, 400 A. nummularia plants would be irrigated, with an energy consumption of 31,319 kWh per day, through a photovoltaic system. In addition, of the 11 strategies of the circular economy, this study complies with 9 of them. It is noteworthy that the combination of brackish water desalination technologies and solar energy to produce A. nummularia would avoid the production of 1.5 tons of CO2. Finally, this study opens potential opportunities for future research, for the implementation of this type of project in rural communities, considering an optimization in the management of saline waste and water.