Sustainable, circular economy hydrogen production by valorisation of electrolyser waste heat for the purpose of direct seawater desalination

To reach net zero and achieve world-leading emissions reductions, the UK Government is targeting low-carbon hydrogen production of 10GW by 2030 (~2 million tonnes/year). There are similar ambitious international strategies, such as in Taiwan with estimated need for around 4.35 million tonnes of hydrogen per year by 2050\. Mutual challenges to achieve these goals include difficulty connecting renewable energy to grid, or variable power supply, resulting in poor hydrogen electrolyser performance.

On the opposite side, many hydrogen production sites have abundant renewable energy resources but do not have sufficient on-site water supply or place unprecedented demands on local water supplies.

Water supply deficits of 4,000MLD in UK are projected by 2050, whilst Taiwan are facing a shortfall of 680MLD by 2036\. In the UK, there have already been enquires for extra 60MLD of water for hydrogen production sites, as the country tackles climate change effects of drought and water scarcity, abstraction reductions, and increasing water demand from population and economic growth.

Desalination is a viable, sustainable solution, but both the UK and Taiwan recognise that current technologies used for large scale desalination are costly, energy intensive and lead to significant greenhouse gas emissions.

Waterwhelm, based in Edinburgh, Scotland, will undertake a 2-year collaboration project with Hephas, based in Hsinchu, Taiwan, to develop a disruptive, circular-economy prototype for sustainable hydrogen production. This UK-Taiwan project, inspired by mutual challenges of ambitious hydrogen targets and the increasing value and scarcity of water, will develop a new hydrogen production prototype that uses its own very low grade (otherwise unutilised) waste heat to desalinate seawater.

This will be achieved through application of a novel separation method with support from Heriot-Watt University.

Waterwhelm will lead the industrial research in the UK to develop the new very low-grade heat system. In Taiwan, Hephas will develop a heat recovery system for their electrolyser that will provide the heat needed. The two new systems will then be integrated.

This circular-economy approach to hydrogen production, through valorisation of the electrolyser waste heat stream, is a new, synergistic innovation for highly efficient hydrogen production. It will result in a disruptive green energy technology that will have significant impact and economic benefits to both the UK and Taiwan.