Solar Desalination Success in Tonga

Drought-resilient clean water solution installed

Solar-Powered Reverse Osmosis System Brings Clean Water to Tonga Island

Facing Water Scarcity in the Pacific

Tonga, like many Pacific Island nations, faces increasing challenges due to drought and limited freshwater availability. Climate-resilient solutions are urgently needed.

Project Snapshot

Location: Tonga
Partners: Australian National University (ANU), Institute for Climate, Energy and Disaster Solutions (ICEDS), Tongan Ministry of Agriculture, Food and Forests (MAFF), Sustainable Water Systems, Solar Water Solutions, Local communities
Installation Date: 2025
Technology: SolarRO reverse osmosis desalination unit for off-grid water treatment

Overview: Clean Water Through Solar Innovation

In response to increasing water scarcity and climate vulnerability in the Pacific, we succesfully installed a solar-powered reverse osmosis system in Tonga as part of a pilot project under the SciTech4Climate initiative. This marks a critical step in deploying sustainable, low-emission technologies to support water and food security in remote island communities.

Project Goals

Provide a clean, reliable source of potable water powered entirely by solar energy
Evaluate the feasibility of solar desalination for agricultural use, especially in drought-prone rural areas
Build local technical capacity through community involvement and training
Contribute to long-term climate adaptation strategies in the region

Implementation and Technology

The installation was carried out in collaboration with local contractors, ANU researchers, and ministry staff. The containerized SolarRO unit was paired with a dedicated solar array and water storage infrastructure, enabling fully off-grid operation. The solar desalination system achieves up to 99% salt rejection, making seawater or brackish sources safe for irrigation and human use. The installation in Tonga features our containerized SW18 model, a compact and energy-efficient solar reverse osmosis unit. Designed for remote and off-grid use, the SW18 unit’s energy consumption is 4,9 kWh and it requirs minimal maintenance. This solution is powered entirely by solar energy — with no need for fuel or grid connection.

Early Impact and Community Response

While operational data is still being collected, early feedback from stakeholders has been positive. Local teams have been trained in operation and maintenance, and crop trials for salt-sensitive species such as taro and yam are underway. The project is already demonstrating the potential for sustainable desalination to enhance water resilience in vulnerable island communities.