Daniel J. Sherman is the Luce-Funded Professor of Environmental Policy and Decision Making and Director of the Sound Policy Institute at the University of Puget Sound. He studies the roles individuals and groups play in environmental politics, policy, and sustainability. In addition to his undergraduate text,  Environmental Science and Sustainability, Sherman published Not Here, Not There, Not Anywhere: Politics, Social Movements, and the Disposal of Low-Level Radioactive Waste with Resources for the Future Press. He is an award-winning teacher who seeks to engage his students directly in environmental decision-making contexts. 

Of all the topics related to environmental science and sustainability, I’ve found that energy is the most abstract for my students. They have an instant interest in the pros and cons of various food choices. They can easily grasp the relationship they have with water use or waste reduction and recycling. But energy is less visible and tangible, even though students know shifting our energy resources and use is essential to decarbonization and addressing climate change. This semester I’ve used five questions to launch lectures and engage students in discussion. These questions help my students see themselves as part of the U.S. energy system—from energy resources to energy services—and anticipate how this system will change as we attempt the fastest energy transition in human history! 

How Much Energy Are We Consuming Anyway?   

Like all animals, we humans get our energy from the food we consume (measured in calories), which we use to breathe, move, and stay alive. In this way humans generate power on average at a rate of about 100 watts.  While 100 watts may power your body, it’s just a fraction of the total energy you use in a day.  Humans have figured out ways to draw on sources well beyond what our bodies can produce—this is our superpower. I often have students brainstorm our energy consumption in the classroom. Direct uses come to mind first with lights, heat, computers, and phones as obvious examples, while indirect uses—the energy required to produce the goods we are using—usually take an extra prompt. Then I point them to author and physicist Richard Wolfson’s depiction of U.S. per capita energy consumption in terms of a fictional quantity of “energy workers” required to meet this demand. If we had to rely solely on human power for our consumption, the average person in the U.S. would be drawing on the power of 100 energy workers. I like to visualize each of us plugged in to a train of 100 people pedaling steadily on exercise bikes, each generating 100 watts. With this metaphor, we can think about the environmental impacts of the actual things providing us with this power and how we might get by with fewer “energy workers” trailing behind us as we carry out our daily tasks. 

How Does Energy Flow from Particular Resources to the Energy Services We Consume? Behold the Sankey!   

Every year Lawrence Livermore National Laboratory illustrates U.S. energy consumption in a Sankey style flow chart with energy resources (coal, petroleum, wind, solar, etc.) on the left and energy services (transportation, industrial, residential, etc.) on the right. It is an amazing teaching tool that enables students to see the relative mix of our energy resource portfolio and follow the energy flows from each resource to particular energy services we consume. These are the real “energy workers” powering our direct and indirect energy consumption. Students can easily see the relationship between petroleum as our largest energy resource and transportation as our largest energy service on the chart. There is also a “super Sankey” at energyliteracy.com that breaks these flows down further so that students can see that within transportation, “light trucks” are drawing on the most petroleum. There are also energy Sankeys for each state, which can lead to revealing contrasts between states that use different resources for electricity. For example, West Virginia is highly dependent on coal while Washington draws primarily on hydropower. When students examine their own state’s Sankey they can start to examine the climate, air, and water pollution impacts of their energy resource mix. Geographic and demographic analysis often reveals considerable distance and disparity between the communities closest to the impacts of power plants, dams, refineries, and mines supplying the energy and the population centers consuming the largest share.   

Where Can We Increase Our Energy Efficiency (While Watching Out for the Jevons paradox)? 

A closer look at the right side of the U.S. energy Sankey reveals that only about one-third of the energy consumed goes toward energy services. More than two-thirds of the energy produced in the U.S. is “rejected energy” that is wasted—serving no productive use. Of course, the second law of thermodynamics teaches us that we will always “lose” a significant amount of energy to productive use as it changes from one form to another. But there are also opportunities to improve energy efficiency. For example, the Sankey shows that the transportation sector of energy services is by far the least efficient, wasting nearly 80% of the energy flowing into it, largely due to the inefficiency of the internal combustion engine powering most vehicles.  Energy conservation professionals will tell you that investing in energy-saving upgrades on the energy services side is almost always cheaper than increasing the capacity of production on the energy resources side. This is one of the reasons that many utility companies manage energy demand by providing incentives for their consumers to adopt energy conservation improvements. But it is important to remember the Jevons paradox. In the nineteenth century, William Jevons observed that efficiency gains in the use of coal power did not lead to less consumption. Instead, the price of coal fell and new uses for the fuel increased overall consumption. For this reason, policy measures are often required to keep efficiency gains from rebounding into increased energy consumption over the long term.   

What Are the Key Challenges of Our Current Energy Transition? 

A Sankey chart is just a snapshot of an energy system that is always in flux. I like to show students an animated version of a U.S. energy consumption Sankey that shows changes from 1800 to the present. They can watch as biomass (mostly wood) is replaced by coal as the dominant energy resource, and then petroleum and natural gas rise in prominence in more recent decades. I then pass out some laminated Sankey charts from the current year with dry-erase markers and ask them to draw out the ways they would like to see the U.S. energy flow change in the coming years. Two related changes always surface.  

First, students recognize the need to reduce the amount of wasted energy, particularly from transportation. This leads them to advocate for more electric vehicles (EVs) with more efficient motors that have the added benefit of greatly shrinking petroleum as an energy resource. Second, they focus on reducing or eliminating the remaining fossil fuel resources in favor of alternatives. If we follow these changes, we are forced to reckon with the most daunting (and exciting) challenge of the current energy transition. The move toward EVs is just the most prominent aspect of the “electrify everything” transition strategy. Other services in the residential, commercial, and industrial sectors could also be electrified. But when we electrify, we have to increase the size of the “electricity generation” box in the middle of the chart—by at least three times its current size (probably more). At the same time, eliminating coal and natural gas decreases our electricity production. So, alternatives with growth potential—especially wind and solar—need to continue to increase exponentially to meet this gap and the growing demand. Because these resources are intermittent, meaning they can’t provide power around the clock on demand, we will need new grid management technology, more and better transmission infrastructure, energy storage, and complementary sources of firm and flexible power (resources that can be applied on demand). We might also consider strategies for urban planning and mass transit that reduce our reliance on cars. Even this simplistic depiction of the current transition helps students understand that this is a massive public/private works project unfolding in their lifetime. 

Where Are You in the Energy Transition? 

It’s easy for students (or any of us) to get overwhelmed with the complexity and scale required to decarbonize the U.S. energy system. I’ve found that if we help them understand that we are in the midst of the fastest energy transition in human history, it can lead to a sense of historical perspective and opportunity. I sometimes ask them to brainstorm business opportunities and non-climate benefits to various aspects of the transition. This sparks their imagination for community and lifestyle benefits, from vibrant walkable urban spaces to cleaner air, more time with friends and family, and more equitable health outcomes. It also helps them think beyond the individual level and consider the role that institutions like community organizations, local governments, and businesses can play to make this energy transition not just faster, but better than those that have come before.   
 

I’ve found that when students understand that they are part of a momentous change unfolding right now, they’re more able and willing to dive into the details of particular energy technologies and the pros and cons of various energy transition strategies and policies. It situates them in a productive problem-solving mode and helps them connect their own lives more directly to the bigger forces shaping our energy future.