Direct seawater electrolysis

February 20th, 2024

We conducted a literature review into the viability and environmental impact of electrolysis of seawater.

Project lead

Dr Bita Bayatsarmadi,

Lead researchers

Dr Yuyang Hou,


The ability to electrolyse seawater would be a game changer, removing worries about fresh water scarcity from the equation.

What we are doing

We conducted an in-depth literature review of direct seawater electrolysis for hydrogen production, encompassing a comprehensive assessment from technical, environmental, and techno-economic perspectives.

photo of a man and a woman reading documents

Yuyan Hou and Bita Bayatsarmadi

In the technical aspect, the research explores the pros and cons of both direct seawater electrolysis and conventional electrolysis coupled with desalination units. This includes a comprehensive review of devices, catalysts, membrane technologies, desalination, etc.

In this project, the environment impact of direct seawater electrolysis has been evaluated. This evaluation includes an examination of its carbon footprint, resources utilisation, and waste management. This project has also explored the techno-economic feasibility of seawater electrolysis technology. Factors such as investment, costs, operational expenses, energy production efficiency and market potential have been considered.

The aim of this work is to provide a comprehensive literature review on seawater electrolysis technology, offering insights into the latest developments and perspectives along with environmental impact.

Outcomes to date

To electrolyse seawater, the following challenges need to be resolved:

  1. Fouling of the system with sediment, algae, bacteria etc.
  2. Poisoning of the catalyst
  3. Membrane pore blockages
  4. Corrosion, due to the highly corrosive nature of salt water.

There are some positive and negative environmental impacts of saltwater electrolysis, compared to conventional electrolysis of seawater that has been pre-treated in a desalination plant.

On the positive side:

  • Saltwater electrolysis doesn’t require a desalination plant. That means that the facility has a smaller footprint and can be built in a smaller space, reducing disturbance to the local environment through land clearing.
  • Conventional seawater extraction methods (e.g. open or subsurface intake) can disrupt water circulation and harm organisms, reducing species populations. Desalination plants use a lot of seawater in the process, for cleaning etcetera. Thus direct seawater electrolysis has a lower impact on local marine ecosystems compared to desalination and conventional electrolysis.
  • A salt water electrolyser would use slightly less electricity than a conventional electrolyser plus desalination plant.

On the negative side, in direct seawater electrolysis, chloride is emitted which is harmful to certain aquatic species.

Project finish date

November 2023

HyResearch record

Direct seawater electrolysis – HyResearch (