As power networks increasingly depend on renewable energy sources such as wind and solar, it becomes more difficult to maintain a balance between energy supply and consumer demand. A recent analysis indicates that water systems, including desalination plants and wastewater treatment facilities, may play a crucial role in stabilizing the grid and creating additional revenue opportunities.
Recent research led by Stanford highlights how water infrastructure, from desalination to wastewater facilities, can make renewable energy more cost-effective and reliable. This study, published on September 27 in Nature Water, outlines a framework for evaluating how water systems can modulate their energy consumption to assist in balancing the power grid’s supply and demand.
“To achieve net zero emissions, we must consider demand-side energy solutions, and water systems are a largely underutilized resource,” stated Akshay Rao, the primary author of the study and a PhD student in environmental engineering at Stanford. “Our method allows water operators and energy managers to make improved decisions on how to coordinate these systems to satisfy both our decarbonization and water reliability objectives.”
As energy grids increasingly rely on renewable sources like wind and solar power, ensuring that supply meets demand becomes trickier. Usually, technologies like batteries provide a means for energy storage, but they come at a high cost. An alternative approach encourages demand-side flexibility among significant energy users such as water transportation and treatment facilities. Water systems, which account for up to 5% of the country’s electricity usage, could provide benefits similar to batteries by changing operations in response to immediate energy requirements, as per Rao and his colleagues.
A framework for flexibility
To tap into this potential, the researchers created a framework to evaluate the benefits of energy flexibility offered by water systems, focusing on both electric power grid operators and water operators. This framework enables comparisons of these benefits against other large-scale energy storage solutions, such as lithium-ion batteries, which store energy when demand is low and release it during peak times. The framework also considers various factors, such as reliability risks, compliance challenges, and the costs associated with upgrading infrastructure to provide energy flexibility.
The researchers applied their method to a seawater desalination facility, a water distribution network, and a wastewater treatment plant, while also examining the influence of different electricity pricing structures in California, Texas, Florida, and New York.
They discovered that these systems could shift up to 30% of their energy usage during peak periods, resulting in substantial cost savings and reduced strain on the power grid. Among these systems, desalination plants exhibited the most promise for energy flexibility, adjusting the amount of water they process or halting certain operations when electricity costs are elevated.
This framework can assist grid operators in evaluating energy flexibility options across various water systems, allowing comparisons with other energy flexibility and storage solutions, as well as enabling adjustments in energy pricing, according to the researchers. Furthermore, it can provide water utility operators with better financial insights for designing and managing their facilities amid the rapidly evolving electricity landscape.
The study underscores the significance of electricity pricing in leveraging flexibility. Water systems subject to varying energy rates throughout the day stand to gain the most. Facilities may even have the opportunity to earn additional revenue by decreasing energy use during peak grid stress, participating in energy conservation programs from utilities.
“Our research equips water and energy managers with a tool to make more informed decisions,” Rao remarked. “With appropriate investments and policies, water systems can significantly contribute to a smoother and more cost-effective transition to renewable energy.”
Meagan Mauter, an associate professor at SLAC National Accelerator Laboratory’s Photon Science Directorate, serves as the senior author of this study. She is also a senior fellow at both the Stanford Woods Institute for the Environment and the Precourt Institute for Energy and holds a courtesy appointment as an associate professor of chemical engineering.
Additional co-authors include Jose Bolorinos and Erin Musabandesu, postdoctoral researchers in civil and environmental engineering, and Fletcher Chapin, a PhD student in environmental engineering during the research.
This research received funding from the National Alliance for Water Innovation and the U.S. Department of Energy.
