a graphic showing the lifecycle of urban water

Water is the earth’s greatest natural resource, yet 2 billion people globally lack reliable access to clean water. As we explore how the Department of Energy’s Industrial Efficiency and Decarbonization Office (IEDO) is working to confront this pressing challenge, we need to start at the place where water and energy systems meet—the energy-water nexus.

Water is used in all phases of energy production, from helping to generate electricity by keeping power plants cool to enabling the reliable use of clean energy sources like hydropower, geothermal, and bioenergy. Water is also a key component of many economically essential industrial processes. Conversely, we use a lot of energy to extract, pump, and deliver clean water to American communities and to treat wastewater so it can be safely returned to the environment.

The interdependence between our water and energy systems is incredibly important, and this delicate relationship is becoming increasingly strained by population growth and the climate crisis. IEDO is working to protect the energy-water nexus by accelerating the innovation we need to efficiently deliver fresh drinking water to American communities and decarbonize the wastewater treatment processes.

"The combination of climate change and population growth will exacerbate the problem of water scarcity in the coming decades. There is a need to develop energy-efficient technologies and systems to utilize non-traditional sources of water, such as various wastewaters and brackish ground water to bridge the upcoming supply gaps."

Technology Manager, IEDO

In the U.S., our water system relies substantially on surface and groundwater for most water needs regardless of purpose, creating a heavy strain on a finite resource. Even so, surface and groundwater are just one part of the water resource puzzle, leaving many other water sources untapped. To meet the growing  demand while conserving energy resources, we must introduce more fit-for-purpose water—water treated to the level needed for a specific purpose—from more sources into the water cycle.

We can bring more water into the cycle by using new technology to efficiently turn wastewater and salty water into fit-for-purpose water—and we can do so with fewer greenhouse gas emissions.

Water treatment systems have been a crucial part of the water cycle; however, they often emit high levels of greenhouse gas emissions, creating an unscalable long-term solution for securing more water. To mitigate the effects of climate change on the water cycle, IEDO is working with the National Alliance for Water Innovation (NAWI) and other partners across industry, government, and academia to invest in technologies to:

"We need to change the D buzzword in the water space from drought to decarbonization, and rethink how we use water, how we produce food, and what the interconnected impacts are. Regionally aligning our resource usage with our country’s natural geographic climate patterns is as important as using this climate data to increase the energy resiliency of our national grid infrastructure."

ORISE Science Technology and Policy Fellow, IEDO

  • Desalinate water from sources such as brackish groundwater to create more fit-for-purpose water while reducing greenhouse gas emissions and energy consumption; and
  • Treat wastewater to meet existing and anticipated environmental standards—and create more fit-for-purpose water—while reducing greenhouse gas emissions.

Desalinating Water:

Desalination is the process of removing excess salts from water to make the water fit for human use. Desalination—especially of brackish (salty) groundwater—could significantly improve the water resilience of water-stressed communities across the United States. The amount of brackish groundwater available in the U.S. is nearly 800 times the total amount of groundwater currently withdrawn nationwide. Opening these brackish water sources can radically impact water resilience in communities across the United States.

Currently, desalination consumes large amounts of energy. However, new innovations in the technology and operation of membrane-based desalination promises to significantly decrease the environmental footprint of desalination processes.

DOE and NAWI recently announced $9 million for projects that will improve the energy efficiency of desalination and waster reuse technologies across the country. Learn more about these projects here.

"As we transition to alternative energy sources, we must recognize that energy and water are inherently connected. We don’t want to do the right thing in the wrong way. We want to make sure that as we transition to alternative energy that we are aware not to further stress or pollute our water."

AAAS Science Technology and Policy Fellow, Energy-Water Science & Energy Program Manager

Treating wastewater:

Wastewater is generated when we use water in our homes and businesses for cooking, washing, and flushing toilets. Nearly all industrial and agricultural processes also create contaminated water as a waste product.

In most municipalities, wastewater from residences, businesses, and some manufacturing facilities routes through a series of sewers to a centralized wastewater treatment plant. Once treated, water is recycled back into the system or released into a local waterway.

Traditional treatment plants follow a multi-step process for water treatment, which uses a combination of biological, chemical, and physical treatments to remove a variety of pollutants.

"We need to think about our ‘waste’ water as a resource, not just something that can be flushed away down our toilets and out of sight…
 There’s so much untapped opportunity to capture and reuse some of this energy potential onsite, and to extract valuable resources like nitrogen and phosphorus that can reduce our need for artificial fertilizer."

AAAS Science Technology and Policy Fellow, IEDO

Many of these steps create extremely high emissions levels, especially in processing biosolids and removing excess nutrients (e.g. nitrogen). Large amounts of energy are also consumed to pump oxygen into the water to facilitate the biological break-down of organic matter. IEDO is advancing technologies that will reduce emissions and energy consumption for wastewater treatment. These technologies will also expand wastewater as a non-traditional water source—and a source of other valuable commodities like fertilizer and biogas.

In December 2022, IEDO issued a $23 million funding opportunity to decarbonize the entire life cycle of Water Resource Recovery Facilities.

Combating water insecurity crucial to a clean energy future that benefits all Americans. IEDO is commitment to advancing water technology and protecting the delicate balance between our water and energy systems.