SCIENTIFIC FOUNDATIONS

Modern research into interfacial solar evaporation showed that heat can be concentrated close to the water surface rather than heating the entire body of water. Published work also demonstrated approaches for combining thermal localisation with passive salt management.

SALINA builds on these scientific principles and focuses on translating them into a practical floating desalination system.

EVAPORATOR DEVELOPMENT | 2024-2026

Developing the Floating Evaporator

From published principles to a practical, scalable architecture.

SALINA’s evaporator development focused on the engineering challenges that determine whether thermally localised solar evaporation can move beyond laboratory demonstrations: precise buoyancy, thermal localisation, passive salt management and construction methods suitable for low-cost deployment.

Controlled Buoyancy

Thermal Localisation

Passive Salt Management

The evaporator must sit at a precise position relative to the water surface while remaining connected to the surrounding saline water. SALINA developed a practical buoyancy approach that can be adjusted accurately without relying on specialist fabrication.

Solar energy must be concentrated close to the evaporating surface while minimising heat loss to the underlying water. Experimental testing in both lab and field conditions, as well as new modelling approaches were used to refine the evaporator geometry and operating conditions.

Continuous evaporation concentrates salt. The floating architecture maintains hydraulic connection with the larger saline body so water can replenish the evaporator while excess salt is returned to the surrounding water.

Scalable Construction

Laboratory concepts must translate into hardware that can be manufactured, assembled and deployed using accessible materials and simple processes. SALINA progressively refined the evaporator architecture with scalability, affordability and practical deployment in mind.

CONDENSER DEVELOPMENT | 2025–2026

Turning Vapour into Freshwater

Once the evaporator was performing efficiently, the next challenge was recovering the generated vapour as liquid water. SALINA’s condenser research focused on understanding how vapour transport, surface positioning and additional secondary condensation systems influence freshwater collection.

Vapour Transport

Condensation Surfaces

Secondary Condensation

The condenser must guide humid air and vapour toward surfaces where condensation can occur efficiently, while minimising losses within the enclosure.

Laboratory experiments examined how surface placement and thermal conditions influence droplet formation, drainage and overall freshwater recovery.

Additional condenser surfaces and ducted configurations increased freshwater production in laboratory tests, but also showed that greater condensation does not automatically translate into easily recoverable water.

System Integration

Improved condensation is only useful if vapour reaches the condenser, heat can be rejected effectively, and the resulting liquid water can be drained and collected. The work showed that these mechanisms must be designed together rather than optimised independently.

INTEGRATED OUTDOOR PROTOTYPE | JULY - AUGUST 2026

From laboratory research to an integrated system.

SALINA’s first integrated outdoor prototype was tested in Malta over the summer of 2026 under conditions designed to simulate operation above a larger saline water body.

The system combined the floating evaporator, controlled buoyancy, vapour enclosure, condenser and freshwater collection into one working prototype.

0.37 m²
Active evaporator area

~1 L/m²/hr
Evaporation rate without condenser

~0.1 L/m²/hr
Fresh water collection with condenser

Next steps: improve the condenser design & latent heat recovery

Recover the heat. Use it again.

CURRENT RESEARCH

The next stage of SALINA focuses on latent heat recovery.

When vapour condenses into freshwater, it releases substantial thermal energy. Current work is exploring how this energy can be captured and reused to drive additional evaporation rather than being lost to the environment.

The next stage will be to integrate latent heat recovery into the full SALINA system and then progress toward controlled marine validation. Continued outdoor testing will assess material sealing, structural integrity, freshwater collection yield and long-term performance under sustained environmental exposure. Future progress will depend on continued research, engineering development and project funding.