Is it time for desalination to set sail? Aquatech Online looks at how viable floating nuclear-powered desalination plants could augment existing water supplies.
The nuclear solution
Imagine heading to the beach one day to look out on the horizon. What do you see? Perhaps swimmers, paddleboarders and boats sailing.
Now instead imagine container ships. Not just any container ships but special nuclear-powered floating desalination plants converting seawater into potable freshwater.
You might not have to imagine for long as this is an idea currently being explored by Core Power, the private UK-based maritime and technology innovation company, who has conducted a report on the future of water.
In the report, Core Power looks at the current water crisis, highlighting that as countries increasingly need to find alternative sources of fresh water for agriculture and domestic use, the need for desalination is growing.
“Modelling calculates that these facilities could create fresh water at a cost of $0.70/m3.”
It stated that in 2020 the total global desalination production capacity reached 112 million m3/day.
The proposes nuclear powered, floating vessels, which could travel to islands or areas affected by drought to deliver clean water.
The BBC quoted Core Power chief executive, Mikal Bøe, as saying: “You could have them moving around on an intermittent basis, filling up tanks.”
Compared to traditional thermal or membrane-based desalination methods, the nuclear alternative works using molten salt reactors (MSR) and heat pipe reactors (HPR) both of which are low-pressure systems that reduce the risks of contact with radioactive material.
The organisation says that its modelling calculates that these facilities could create fresh water at a cost of $0.70/m3, a “23 per cent reduction on current costs”.
Core Power is considering two sizes of deployment:
- An MSR producing 80 MW of electricity to provide a maximum of 450,000 m3d/day of drinkable water, in a Panamax size hull (cargo tanker).
- A smaller HPR producing 10 MW could produce up to 60,000 m3/day in a feeder-type hull (small tanker).
Addressing the question of “why nuclear”, report author Rory Megginson, director of analytics at Core Power, said: “The current proposals for floating desalination rely on either onboard fossil fuel generators or pairing these systems with specifically co-sited or so-called stranded renewables.
“While these can offer a cheap production cost of electricity, they suffer from uncertain reliability dependent on increasingly erratic weather patterns.”
A growing sub-sector
Floating desalination is not a new idea, with Saudi Arabia taking delivery of the first of three desalination barges, the largest ever built.
Meanwhile, other notable innovations include taking desalination deep underwater.
Aquatech Online recently investigated Norwegian start-up Waterise and its novel approach to operating a modular desalination system, 400m underwater on the seabed.
“Each subsea plant module is expected to produce 13 million gallons of fresh water per day.”
Engineering and fabrication company Rosenberg Worley was awarded the contract to develop a cost-efficient solution for the plant's modularisation, installation and operation.
Each subsea plant module is expected to produce 13 million gallons of fresh water per day (59,000 m3/day) – said to be enough to support a mid-to-large city.
At the time, Borja Blanco, CEO of consultancy Aqua Advise and chief commercial officer at Waterise, told Aquatech Online that the organisation is "getting pretty close to a real project opportunity" but did not elaborate further.
Similarly, Oisann Engineering, which has developed a system called Waterfountain has also entered the fray.
The company has various ship desalination designs, from large ships to small buoys, but they all work on the same principle of subsea desalination.
Overcoming potential challenges
Like any concept, it remains to be seen whether floating nuclear-powered desalination will make it from theory to reality.
It would provide a low-cost high yields volume of fresh water without the need to build large plants near the oceans to reduce piping networks.
“By marrying this technology to the cost-competitive electricity produced by floating advanced nuclear reactors, it will be possible to produce reliably priced dispatchable water and power for water-stressed nations,” concluded Megginson.
Potential challenges to overcome include pumping desalinated water ashore and finding a workforce with both offshore and desalination expertise.
Core Power's idea of using nuclear-powered desalination plants will need to undergo research and further study to assess just how viable it is in practice.
- Partnerships to by-pass chemical treatment for 'greener' desalination
- Saudi claims the world's largest (ro) desalination plant title
- Subsea desalination moves forward following waterise partnership