Water Energy Matters

Issues related to the water-energy nexus


The need for a change in understanding

Last year, Texas experienced the worst single-year drought in recorded history. Ken Saathoff, an official with the state electric grid operator, said “we will be very concerned” if  it does not rain by spring. This seems odd at first. Why would someone who works in the electricity sector care so much about rainfall and drought?

Examples of interdependency between the water and carbon cycles. (Image courtesy of National Conference of State Legislatures)

Saathoff’s concern highlights the important relationship between two resources that has been gaining much attention (and concern) in recent years. Water and energy were once thought of and treated as separate issues. Growing population demands and resource shortages, however, underscores how much these two resources are interlinked.

Energy means a lot of things. We usually say we need to eat so we have the energy to do work. And that is what energy is fundamentally: the ability to do work. In this particular post, we’ll be talking about a specific kind of energy: electric energy. Electric energy plays an important role in almost every aspect of our lives: it lights stores, makes factories work, keeps the refrigerator cold, and powers our electronic devices.

What may not be as apparent is that electric energy also helps bring the water we use. The intersection of water and energy issues is known as the “water-energy nexus.” It points to how much energy is needed to pump, process, transfer, store, and dispose water. It also shows how much water is used to extract, generate, and transmit energy.

An overview of the process of extracting, generating, and transmitting electrical energy, and some of water’s role in the process. (Video courtesy of Energy Now!)

Most sources (including Sandia National LaboratoriesNational Conference of State Legislatures, and Circle of Blue) say that about 4% of national electricity use goes to moving and treating water. In some regions, this percentage is much higher. For example, the California Energy Commission reports water-related energy use constitute 19% of the state’s electricity and 32% of its natural gas. A large part of the issue is that where water is needed is not always where it is most abundant, requiring large amounts of energy to move water over distances.

California Aqueduct

Large, long-distance water aqueducts transport water to Southern California, requiring much energy along the way. (Photo courtesy of Wikimedia Commons.)

Generating and distributing energy also require large amounts of water. The Network for Energy Choices says that U.S. power plants use more fresh water than irrigation while Sandia National Laboratories says that agricultural water use is still the highest. Despite arguments in ranking, most organizations (including Network for Energy Choices, Sandia National Laboratories, and National Renewable Energy Lab) agree that U.S. power production requires 140 to 200 billion gallons of water daily. That’s 200,000,000,000 gallons! This accounts for almost 50% of all national freshwater withdrawals.

This means that in times of drought, when rivers or reservoirs dry up, power plants in hard-hit areas may not have enough water to operate. Water is also crucial for other parts of energy production, including energy extraction, refining and processing, and transportation. For extraction, drawing oil and natural gas from the ground with hydraulic fracturing techniques requires copious amounts of water. For refining and processing, water is needed for refining oil and gas, as well as for growing and refining biofuels. For transportation, water is needed for hydrostatic testing of energy pipelines.

Given water’s tremendous role in energy production, it is no wonder that Saathoff was closely watching the Texas skies for rainfall last September. If drought conditions continued into spring, it would have major impacts on the state electric grid.

Director of the Stockholm International Water Institute Jakob Granit says that given the scarcity of water resources, stronger regional cooperation will be important in making sure power plants are located in the best places. The implication is that power plants should be located near abundant water sources so that 1) they are not as susceptible to climate change, and 2) less energy will be used to transport water over long distances.

Granit’s sentiments also point to an increasing trend of local and regional planners who realize the importance of examining water and energy issues together. The next blog post will look at what efforts are happening at the regional, state, and federal levels to address this critical and dynamic relationship. Stay tuned!