Located in Polynesia in the Pacific Ocean, Easter Island is one of Chile’s greatest tourist attractions. Thanks to its pristine soft sandy beaches and turquoise waters, majestic dormant volcanoes, some with incredible lagoons, and the enigmatic Moai statues scattered across the island, tens of thousands of visitors arrive each year looking forward to experiencing these and many other wonders.

The tourists mainly come in the summer, at the same time as the lack of rain and high temperatures, apart from igniting the religious celebrations; a shortage in irrigation water for crops is produced. Thus, the island is forced to transport 52% of the fruits and vegetables consumed annually from the mainland.

"Given the reduced availability of water resources, farmers in the area must decrease production or use potable water for irrigation during these months, greatly increasing the price of their products and making them less competitive compared to the offerings from the continental mainland" explains Carolina Cuevas, head of the Fundación Chile Sustainability project which, with the support of local stakeholders, seeks to generate irrigation water using solar-powered technologies.

The expert notes that the first phase of the project was a success; they managed to validate the operation of a small seawater desalination plant designed by the foundation according to the specific conditions of the island. This, despite the fact that the coasts of Rapa Nui have a higher level of salinity than the continent in general and that, after the rains, a significant amount of sediment had concentrated thanks to dirt movement, which also implied the development of specific operating protocols.

Launch

It was in late 2013 when Cuevas, who was delivering a presentation on the progress of other desalination projects that Fundación Chile is running in the north of the country to generate potable and irrigation water for isolated communities, was contacted by a secretary of the island’s Clean Production Council to let her know the problems being faced and interest her in developing a similar project on Easter Island.

This quickly resulted in the formation of a team that started collecting information to develop a proposal to allow them to start looking for partners and leverage funding, which eventually came from the Regional Government of Valparaiso’s Innovation Fund for Competitiveness, which is responsible for Easter Island. In addition, the Chilean National Forestry Corporation (CONAF) provided them with one of the nurseries dedicated to repopulating native species, which houses about 4 thousand specimens, including some endemic species such as Sophora Toromiro, for this test.

They installed a small desalination plant prototype at the nursery, capable of producing one cubic metre of water per hour of operation and which uses photovoltaic panels to power 70% of its 4kWp consumption with energy from the sun. This gave them their first glass of irrigation-quality desalinated water in May this year, so the last few months have been devoted to study its performance.

"Today the islands fuel their power generation needs with diesel; therefore everything you can generate from renewable sources helps replace this highly polluting fuel, contributing to the sustainability of the territory," emphasises Cuevas, noting that, although the plant still needs to power 30% of its operations via fuelled network, the solar system continues to work and feed the system when it is turned off, so depending on how much radiation there is on a certain day, it is possible to power it 100% using solar energy.

Initiating the second phase

The project leader notes that the CONAF nursery, where the first tests were performed is a small one, so the second phase in which technology will be directly implemented on a farmer’s estate will be a challenge. Furthermore, the large producers are far removed from the power grid, so they will have to evaluate a 100% solar plant, or another alternative using the same type of source, to treat water of poorer quality. However, Cuevas notes that there are several smaller producers near to the village that could operate similar systems to the one currently used at the nursery, but the ambition is to reach everyone.

"We are now evaluating what is most feasible and creating a project to move to the second phase; this is all due to the major opportunity niche that was opened with the results of the first phase. For the moment there are no funds available, so until then we will continue moving in this direction," says the Fundación Chile expert.

@AleMaturanaB

For more information, visit: http://www.fch.cl/

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