When it comes to producing clean water, Australian utilities are world leaders. Now, they are required to consider how they can effectively deploy clean energy too, and that presents a whole new raft of challenges.
As the water sector transitions to net zero, there are plenty of gaps to fill when it comes to effectively using and producing renewables within the sector, including how to tackle the issue of variability and storage.
Given the global energy footprint involved in treating and distributing water is significant, the water sector has a key role to play in leading and informing transitional strategies.
“We’re in the middle of an energy transformation, the scale and speed of which we haven’t seen since the industrial revolution,” Kelly Charlesworth said, Associate Principal for Energy Transition at Arup. “Coal fired power stations are quickly being retired and replaced by renewable energy zones and pumped hydro storage.”
As we move toward a net zero economy, Charlesworth said regional areas in particular will see an economic transition.
“Water use, inherently together with energy, are the key enablers of this transition, and increasing water scarcity and competition for water are challenges we can’t ignore,” she said.
Regional areas looking to support new industries and forms of manufacturing – such as renewable energy, advanced agriculture, critical minerals and clean energy and fuels, such as hydrogen or biofuels – will find that these opportunities are underpinned by sustainable, reliable power and water supplies.
“From a utility infrastructure perspective, industrial development in Australia is usually on the back of the availability of water and power,” Charlesworth said.
“Selecting the best location for these assets to support new industry is a strategic planning exercise, and as a nation we've never done anything on that scale, with so many moving parts at once. Given the enormity of the task and the various factors involved, we need to fast track that planning process now.”
Given that the scale of renewable energy development is beyond anything that's been seen before, water will continue to play an integral role.
At the same time, there is increasing uncertainty and risks associated with the changing climate, so energy and water supply resilience and security are becoming more critical.
Charlesworth said the sector also needs to consider what a ‘just transition’ looks like in practice. “The definition of what is ‘just’ is evolving because of our growing understanding of the impact on people, communities, and environments including our First Nations people,” she said.
While the need to transition to renewables to help achieve sustainability goals is clear, the infrastructure required to get there requires careful planning.
“The energy-water nexus is getting more intertwined with pumped hydro energy, which requires new dams, as well as new fuels like hydrogen, which requires sustainable water supplies,” Charlesworth said.
“One difficulty we face with hydrogen is that we don't want every proponent to come in and build a new desalination plant. It’s not always going to be the best option for budget and for the environment, so we need to have other options on the board. Recycled wastewater, for example, is an important consideration for the green hydrogen industry.”
Even in planning, climate change modelling becomes critical as natural resources are subject to variation. New Zealand, which has an abundance of hydroelectric power, is seeing more frequent dry winters, which can impact electricity supply through lack of water. Closer to home, the national discussion around developing a green hydrogen market in Australia is progressively becoming more aware of the water risks associated with the industry's development on the driest continent on earth.
AECOM Water Leader in Australia and New Zealand Laura Fluck warns that the intermittency of renewable energy sources, particularly for the municipal part of the sector, remains a key challenge.
“Utilities have to work through how to meet the reliability and operational requirements of their assets with intermittent renewables such as wind and solar,” she said.
Investing in storage such as battery and pumped hydro generation systems is one solution, but Fluck cautions overloading on infrastructure. “There needs to be a balance between the capital – not just cost, but the carbon element of creating more infrastructure – and the energy usage itself,” she said.
Hydrogen power is extremely water intensive, both as feedstock and also for its cooling mechanisms. “Typically, if seawater is utilised, the amount is in the range of 150-170 litres per kilogram of hydrogen produced,” Fluck said. “However, high-quality water doesn’t always have to be utilised in the cooling area.”
Fluck points to SA Water’s Zero Cost Energy Future (ZCEF) program as an example of a transformational project.
Undertaken between 2019 and 2022, its aims included getting the utility to net zero emissions by 2030, base load requirements operating on 100% renewable energy by 2030, and net zero waste by 2040.
“The program looked at seven key initiatives including demand scheduling, energy efficiency, energy storage, 154MW of new solar and 34MW of battery energy storage, as well as energy market levers to drive a zero-cost energy system,” she said.
In the race to build systems and infrastructure to get to net zero, Fluck said a key area of consideration for the water sector is Scope 3 embodied carbon emissions linked to capital expenditure – that is, emissions that result from assets not owned or controlled by a utility, but that the utility is indirectly responsible for along its value chain.
“We talk a lot about operations, such as how utilities can minimise energy demand and make their assets more energy efficient,” she said.
“But when it comes to capital projects, we need to think about what materials we are using, and push the industry to explore, create and adopt newer, lower carbon materials.”
Fluck suggests that, in some cases, the water sector can consider nature-based solutions instead of concrete, such as creating naturalised stream environments compared to traditional concrete lined drains, which have the added bonus of co-benefits flowing to local communities.
“If concrete were a country, it would be the third highest carbon emitter on earth,” Fluck said.
“Steel making and cement production are the two highest emitting industrial sectors, and looking at the approach to decarbonising these sectors is key to the overall equation.”
This article was originally published in the 2024 edition of Current, the Australian Water Association’s annual magazine.