Is recycled water the key to growing a sustainable hydrogen economy?
This story was sponsored by Jacobs.
There is a growing awareness that recycled water will help ensure Australia’s water security. But the resource could also help power the development of a sustainable form of energy storage: hydrogen.
Australia’s Chief Scientist has described hydrogen as “a fuel for the 21st century”. Like natural gas, it can be used for heating and cooking, and it can replace diesel and petrol to power electric trucks, trains and cars.
If it was produced using low- or zero-emissions energy sources, hydrogen could also help decarbonise some of Australia’s domestic industries and create a new export industry.
But most of the hydrogen produced today for industry is made from fossil fuels. Although the electrolysis-based production model is often considered a green alternative, applying this model in Australia today would still create greenhouse gas emissions. This is because the model relies on energy purchased from the electricity grid to split freshwater into hydrogen and oxygen and the nation’s electricity grid is still mostly made up of coal-fired power.
The other challenge of producing hydrogen sustainably is that it requires high-quality water, and lots of it. In fact, to produce enough hydrogen to replace the 39 million tonnes of imported diesel and petrol fuel used by some of Australia’s industries each year would require an additional 99 GL of water. That’s equivalent to an extra 1.7 million people living in our cities.
With these challenges in mind, a team of specialists at Jacobs recently put together a white paper looking at the potential for the development of a sustainable hydrogen economy in Australia.
They found that if Australia is to become a global leader in hydrogen production, the water sector will need to be a bigger part of the conversation.
What role does the water industry have?
Population growth and climate change are already putting pressure on the country’s water resources. This makes using potable water to produce hydrogen an unpalatable idea.
But rethinking the supply chain – shifting from grid-purchased electricity and drinking water to renewable energy and recycled water – could help create a sustainable industry.
In fact, the Jacobs team found that changing the source of water for hydrogen production from potable to recycled water without altering any other variables would result in savings of about $29 million over a 40-year period.
“The economic outcomes would be further enhanced if the monetised benefits of reducing environmental discharges from wastewater treatment plants were included in the modelling,” Jacobs’ Regional Solutions Director for Drinking Water and Reuse John Poon said.
Using recycled water would also avoid the risk of potable water for industrial use being rescinded in times of drought, as has happened in the past.
A new revenue stream
According to the white paper, using recycled water for hydrogen production could also prove lucrative for water authorities, which have a regulatory imperative to keep costs down for customers.
Many wastewater treatment plants already have the facilities to produce recycled water. Instead of discharging this into waterways, the water could be used to produce hydrogen gas, which could be sold for a variety of applications.
“Given wastewater treatment plants tend to be located in close proximity to towns and cities, distribution costs could be minimised, potentially attracting a large number of different buyers for the hydrogen,” Jacobs’ Regional Technical Director for Energy Markets Walter Gerardi said.
The pure oxygen that is created during hydrogen production could also provide a financial benefit for utilities by making the digestion process more efficient. This would reduce capital and operating costs of tanks and blowers, while decreasing the energy needed to operate them.
Finally, any unused oxygen could be sold for use in ozone generation for water treatment, for use in industrial furnaces, or for anaesthesia and oxygen therapy.
Cross-sector collaboration needed
The white paper concludes by highlighting that collaboration across sectors will be vital to create a truly sustainable hydrogen economy in Australia.
This would need to take into account the environmental and economic challenges of hydrogen production, and recognise the role water could play in the establishment of this emerging energy storage solution.
“There is a need for a cross-sector approach to effectively leverage any future benefits of a large-scale hydrogen economy,” Poon said.
“As with any emerging technology nearing commercial deployment, it is vital that a holistic view is applied in early phases of development to identify risks and maximise potential.”
For any media enquiries, please contact Nayyar.Ehsan@jacobs.com.