The large desalination plants produce fresh (drinking) water in many areas where this resource is scarce, but they do not always, at least up to now, work efficiently (low consumption of energy generated with fossil fuels) nor do they guarantee the reduction of the environmental impact that It can lead to the spillage of brine or the occupation of land on the seafront.
An alternative for specific cases is the construction of small desalination plants with new technologies that make it possible to take advantage of renewable energy in the water production process with reverse osmosis filters.
One of the most innovative initiatives in this new sector are the floating desalination plants developed by the Canadian company Oneka Technologies, one of whose pilot plants was installed this year on the coast of Algarrobo, on the central coast of Chile, with the help of the Agreement between Canada and Chile on Environmental Cooperation and a financial contribution of almost five million dollars.
The basic device consists of a floating platform anchored to the seabed and with a pipe that transports fresh water to the shore. The initial device, dubbed the Iceberg class, harnesses wave energy to inject pressurized water into a reverse osmosis desalination system, which is the most widespread technology among desalination plants and the most sustainable. Passing through a membrane system, salt is removed and up to fifty cubic meters of water are produced per day. This amount is enough to cover the needs of one hundred families of four people.
The system has been designed in a modular and scalable way. On the one hand, several units can be installed side by side, and on the other, there are units of different sizes. Along with the current basic model, there are two smaller ones. The smallest has been proposed as an easy-to-install platform that allows for the immediate generation of fresh water in the event of humanitarian catastrophes in coastal areas.
The design of the pilot plant allows operation when the waves reach a minimum height of one meter and the seabed is between thirteen and thirty meters deep for the system to work optimally. Regarding its dimensions, the Iceberg class machines measure eight meters long by five meters wide and weigh eleven thousand kilos.
The new floating desalination plants have been conceived from the outset as a technology based on the circular economy. In addition to using wave energy to pump the water and taking advantage of solar energy to control on-board sensors, they are made mostly of recycled plastic. Specifically, the basic model recycles up to 170,000 plastic bottles, highlight the promoters of the project.
Also in their defense, the promoters assure that each unit has a useful life of between fifteen and twenty years, and that they only require between three and seven annual visits for maintenance tasks. For now, the amount of fresh water produced is limited and work is underway to develop industrial-scale floating desalination plants. These first units could enter the testing phase throughout 2023.
