Water, hydrogen and the energy revolution

As hydrogen emerges as a growing component in the energy transition, managing the sector's water footprint is becoming increasingly important. The production of blue and green hydrogen, important parts of the move to cleaner energy, both need large amounts of water. With hydrogen set to play a crucial role in the future energy mix, sourcing, treating, and recycling water will underpin sustainable production.

Here, Xylem's Kishor Nayar Director of Business Vertical - Chemicals Industry, and Alex McDonald Director of Business Development - Heavy Industry, explore the sustainable water management strategies the sector can deploy to balance water consumption with hydrogen production. With the right technology and approaches, the sector can reduce environmental impacts and ensure consistent supplies to minimize risk and maximize growth.

Xylem's Kishor Nayar and Alex McDonald

What role does water play in hydrogen production and "clean" energy, particularly blue and green hydrogen?

All hydrogen production requires water as a fundamental input, particularly when it comes to green and blue hydrogen - the two main sustainable production methods.

Green hydrogen, which is produced by splitting water into oxygen and hydrogen through electrolysis, is showing real promise as an efficient "clean" energy source. As it utilizes renewable energy such as solar or wind, its carbon footprint is lower when compared to conventional hydrogen, however, the water demand is significantly higher.

Blue hydrogen is produced by reforming natural gas, where the carbon emissions are captured and stored. While blue hydrogen has a lower carbon footprint than conventional hydrogen, its carbon footprint is higher than green hydrogen. This is due to the carbon footprint inherent in natural gas production and transportation. However, in our experience, the water demand on blue hydrogen projects is lower than green hydrogen on a per kg hydrogen produced basis.

How important is sustainable water management in hydrogen generation?

The water and hydrogen energy sectors are deeply intertwined, and a joint management approach is necessary to identify potential tradeoffs and mitigate future risks. While green hydrogen is a sustainable production method, the sheer volume of water needed, coupled with the treatment and purification processes that precede electrolysis, contributes to greater water consumption and energy expenditure.

As hydrogen emerges as an important decarbonization pathway for heavy industries, with $570 billion in global green hydrogen projects already announced, water management strategies need to stay in step for it to live up to its promise as a truly sustainable energy source.

With production set to accelerate at a transformative pace, so too will water consumption. Estimates by IRENA and Bluerisk show that about 2.2 billion m³ of freshwater is withdrawn for global hydrogen production every year, about 0.6% of the energy sector's total freshwater withdrawal.

Current estimates show that withdrawals for global hydrogen production could triple by 2040 and increase six-fold by 2050. With 35% of planned green and blue hydrogen projects in areas under high water stress, these sites are vulnerable to water shocks and carry a risk to local water sources if they are not well managed.

As the sector grows, how can companies make the most of water to minimize risk and maximize growth?

The water sector's involvement in hydrogen production is not just about providing the necessary resources, but also about innovating to make processes more efficient and less harmful to the environment.

The fragmented market for alternative fuels requires a mix of technologies to assemble solutions for process water, wastewater treatment, and recovery and recycling. These technologies are essential, as they help to manage the water resources used in the production and cleaning process.

While the hydrogen revolution presents fresh challenges and opportunities for innovation, tried and tested approaches to moving and treating water and managing discharge remain the bedrock of good water management.

From UV systems for water treatment to advanced electro-deionization (EDI) technology for water polishing, there are sustainable solutions that enhance efficiency and minimize environmental impact.

What steps should companies take to ensure a sustainable approach to balancing water consumption in hydrogen generation?

Companies can draw on experience from other sectors, such as the semiconductor industry, and look at how leaning on partners to develop a holistic approach to fully designing, building, and operating water systems can help make the economics of sustainability make sense.

The first step for companies is to assess the availability and quality of water in the area where the hydrogen production facility will be built.

Freshwater may offer the best business case for green hydrogen generation because it minimizes the need for purification treatments, but this might not be possible if the plant is in a water-stressed area. Some companies may need to turn to desalination or even purified wastewater.

They will also need to deploy the right portfolio of water treatment technologies, which will largely depend on the quality of the water available. Water for green hydrogen will require both treatment technology, such as reverse osmosis, and polishing, and technology such as electrodeionization, to reach the purity levels needed.

The water then needs to be separated using a combination of coated anodes and cathodes to generate hydrogen, which also generates wastewater streams that can be expensive to manage and dispose of.

Water treatment technologies can help to reduce the cost and environmental impact of managing these streams, while also opening options to recover and reuse water resources.

For instance, electrolysis process water is only one element of the system's overall water needs, with cooling water usually a larger overall requirement. However, with the right technology, process water can be recirculated and used for cooling, making the operation significantly less water intensive.

Are there any benefits to co-locating hydrogen production and municipal wastewater treatment facilities?

Co-location between hydrogen facilities and wastewater treatment plants can be extremely beneficial in terms of leveraging synergies for greater efficiency and sustainability. The reuse of wastewater in the process reduces overall water consumption. Utilities can also explore opportunities to utilize excess oxygen generated during hydrogen production for aeration in wastewater treatment. It's a win-win scenario that optimizes resource utilization across the board.

What role can digital play in enabling sustainable water management strategies for hydrogen production?

Like everything else, the durability and reliability of equipment are crucial to hydrogen production processes, and this can be improved significantly with digital technology. Remote monitoring and predictive data analytics ensure that feed and effluent water quality passes muster. Data can also be continuously analyzed using machine learning to identify and resolve issues before they become problems. This allows for predictive maintenance to keep the system running smoothly and minimize the risk of failure.

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