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MPhil in Engineering for Sustainable Development

global challenges, engineering solutions

Studying at Cambridge

Matias Hanel

Sustainability Assessment of Desaliation Plants Powered with Renewable Energy: A Case Study of the Antofagasta Region in Chile.

Of all the globally available water only 2.5% is fresh and only 1.2% of it is on the surface to be easily used. Regionally, there are also significant variations in water availability from one location to another. Water is a local resource and it is difficult and costly to move. The Antofagasta region in northern Chile contains the driest desert in the world, but it is also a key part of the Chilean economy because it is rich in copper, nitrate, lithium and other minerals that require large amounts of water to be exploited. The country also relies on imported fossil fuels but is rich in unexploited renewable energies. The Antofagasta region is especially interesting for solar and wind power.

The region has more than 500kms of coast and is already using reverse osmosis desalination plants to provide fresh water. However, desalinated water requires energy which is primarily provided by fossil fuels. This raises the question of whether desalination can be more sustainable by using renewable energies to provide for the future water demand in the Antofagasta region.

This dissertation’s aim is to estimate the required installed capacity of renewable energy that would be able to generate the yearly energy to produce and distribute the Antofagasta Region’s water deficit with desalination by 2030. The future water demand by sector and basin is described, and then compared to the water availability to establish the deficit. With this regional deficit a desalination system masterplan is developed to estimate the energy demand implications. Then the different renewable energies (e.g., solar, wind, geothermal) and their potential in the region is studied to pair them with the required energy.

Results show that wind and solar technologies could independently provide all the required energy for desalinating seawater for the Antofagasta region. This raises new questions on the practical implications on implementation. Recommended further work is to determine how the variable energy generated by renewables could be better coupled to demand, and how the other impacts associated with desalination, such as brine disposition and land use, be mitigated.