SolarDune

The starting point is freshwater.

Greening a desert ultimately runs into a simple constraint: water. SolarDune started from the question of whether seawater could be brought into a hyper-arid environment and converted into freshwater by making use of the abundant sunlight and heat available there.

As the idea developed, photovoltaic power and a data centre became part of the system. A data centre needs electricity and cooling, but it also produces a steady stream of low-grade waste heat. SolarDune explores whether those needs and outputs can be connected to seawater evaporation and condensation instead of being treated as separate systems.

In engineering terms, the reference concept combines photovoltaic electricity generation, data centre cooling and waste-heat recovery with a large-scale, low-pressure humidification–dehumidification (HDH) desalination cycle. Warm seawater is spread across enclosed evaporation decks; humid air moves through the structure; and a large condenser recovers part of that moisture as freshwater.

SolarDune integrates established physical processes into a single system for electricity generation, seawater evaporation and condensation, heat management and freshwater production.

Evaporate seawater, move the moisture, condense freshwater.

The SolarDune reference design treats electricity, water, air and heat as four linked flows. Changing one of them affects the others. The system is therefore closer to a regulated thermodynamic environment than to a conventional desalination plant with one fixed process line.

Three stacked evaporation decks create a large seawater surface inside the structure. The current concept uses broad, shallow channels and low-pressure airflow to bring warm humid air toward a condenser on the north side. The cooler desert night is intended to help reject heat and improve condensation.

The data centre provides an economic use for the photovoltaic electricity while supplying a continuous source of low-grade waste heat that can support freshwater production. By designing renewable electricity, computing, cooling and heat recovery as parts of the same system, freshwater becomes an additional output of infrastructure that serves several functions simultaneously. This integration is central to the economic logic of SolarDune.

Salt aerosol, corrosion, demisting, brine disposal, dust, pumps, fans and maintenance remain practical engineering problems to be solved during prototyping.

The aim is gradual desert greening.

Producing freshwater only matters if the water can be used sensibly. The current concept therefore links freshwater production to a gradual restoration strategy around the structure rather than to an immediate attempt to transform a large desert area.

A possible first stage would use nurseries or greenhouses, drip irrigation, pioneer vegetation, soil stabilisation and windbreaks. If vegetation survives and soil conditions improve, later stages could introduce more complex planting and, where appropriate, productive species suited to dry climates.

This part of SolarDune is particularly site-specific. Water demand, species selection, soil quality, salinity, evapotranspiration, wind exposure and establishment losses would all need local testing. Ecological restoration is therefore an intended use of the freshwater, not a guaranteed outcome of the current design.

Designed for harsh desert conditions.

SolarDune is intended for an environment where extreme heat, dust, saline water and remoteness make complex infrastructure difficult to maintain. The concept therefore relies on large, simple geometries, low-pressure flows and relatively low-complexity components that can be inspected, repaired or replaced without highly specialised equipment. Wherever possible, the design uses robust materials and natural processes such as convection, evaporation and day–night temperature cycles. Where pumps, fans or other mechanical equipment are required, the aim is to use conventional and readily replaceable technology. Maintainability and replaceability are treated as design requirements.

A preliminary 3D model.

An interactive 3D CAD model in Onshape shows the current SolarDune reference geometry. It is useful for understanding the scale and wedge shape of the structure and how the main spaces fit together.

The CAD model is a conceptual reference, not a construction drawing. Dimensions, internal layouts, materials and subsystem interfaces may change substantially after more detailed modelling and testing.

The calculations and assumptions are public.