In This Issue
Summer Bridge on Engineering the Energy Transition
June 26, 2023 Volume 53 Issue 2
This issue explores the energy transition needed to address the mounting threats of climate change. The articles are an excellent resource to help inform meaningful decisions and steps for energy-related contributions to reduce carbon emissions.

Guest Editors’ Note Analogies to Communicate the Engineering Challenges of the Energy Transition

Wednesday, June 7, 2023

Author: Tom Degnan and Tim Lieuwen

“I especially love analogies, my most faithful masters, acquainted with all the secrets of nature…. One should make great use of them.”

      — Johannes Kepler

This century’s greatest engineering challenge may be orchestration of the energy transition required to meet net zero carbon goals. But the magnitude of the energy transition is difficult for many individuals to grasp. So we turn to analogies.

Like Johannes Kepler, engineers and scientists love analogies. They can spark creativity. Leonardo da Vinci frequently resorted to analogies to guide his insights into the human body. They are a means to simplify communication and help people become more comfortable with concepts that are difficult to comprehend. For scientists and engineers, analogies can be useful to explain the essence of something that is technically complex.

Is there a good analogy to help convey the essence of the imminent energy transition?

Pundits and politicians attempting to describe the energy transition have drawn analogies to the Manhattan Project (1942–45) (Shanks 2022), the New Deal (Dolsak and Prakash 2019), and President John F. Kennedy’s 1961 challenge to land a man on the moon (Clemens and Aliakbari 2022).

Like the Manhattan Project, the societal need for a transition in energy sources is almost existential. There is a strong sense that we cannot afford to fail. Also like the Manhattan Project, there is a need to assemble the nation’s best technical talent, in this case to focus intensely on transitioning away from traditional hydrocarbon fuels.

Drawing an analogy to President Franklin D. Roosevelt’s New Deal is a favorite tactic of politicians. Like the New Deal, the design, development, and deployment of a new US energy infrastructure require a “top-down” policy-driven program that captures the populace’s attention and embraces a grand vision. The two are similar in their need to draw heavily on the public and private sectors.

President Kennedy’s manned lunar landing challenge is often cited as an example of a visionary communicating a truly aspirational goal where technical uncertainty stands squarely in the way of success. It is easy to envision parallels between the engineering and logistical challenges related to landing a man on the moon in the late 1960s and those associated with successfully converting the energy system to a net zero carbon system by 2050.

But none of these analogies is particularly apt because the energy transition is intrinsically different. For one, it is a global challenge, not a domestic one. Coordination and consensus among countries with varying energy policies, different infrastructures, and vastly different economies will be essential. And although urgency is a common denominator, the time frame for achieving a successful outcome is different: about 25 years for the energy transition vs. 10 years in each of the three historic analogies.

The longer time frame for transforming the energy infrastructure accurately reflects the time required for designing, installing, and refining a new global energy system. Unfortunately, establishing more distant time targets detracts from the sense of urgency and allows seemingly more pressing, though arguably less important, priorities to intervene. The recent focus on energy security is a good example: European electricity suppliers reverted to using more coal when confronted with the threat of disruptions in the natural gas supply.

Are there better analogies? For inspiration, we might look to Greek history and Plutarch’s ship of Theseus. The ship was made entirely of wood, which deteriorates over time and has to be replaced. In Plutarch’s telling, the wood planks of Theseus’s ship were replaced one at a time over a long period, until no more of the original wood remained.[1]

Like the ship of Theseus, societies must replace existing energy infrastructure with an entirely new energy infrastructure over an extended period while operating and maintaining, without interruption, the current hydrocarbon-based energy system. And this has to be done safely, economically, and equitably. To further extend the analogy, a “larger ship” will be needed to accommodate both the 775 million people who currently have no access to electricity as well as a global population that is projected to grow to 10 billion. And the reconstructed ship will have to be more durable to withstand the increases in climate variability and in the frequency of severe weather events. It amounts to a magnificent but daunting technical juggling act.

Much has been written on the topic of the energy transition, so why do we need this special issue of The Bridge? Much of what’s been written has focused on basic science, technology advances, funding requirements, or government policy. Less has been written about the engineering challenges, rooted in rigorous lifecycle analysis and systems and resiliency thinking. These articles are intended to fill this gap.

The concept for a Bridge issue dedicated to the engineering challenges associated with the energy transition originated from a discussion between NAE president John L. Anderson[2] and his President’s Business Advisory Committee (PBAC) in early 2022. Planning for the issue evolved concurrently with developing the groundwork for the 2022 NAE Annual Meeting. The two share the same theme: Engineering the Energy Transition.

The most critical role of engineers and scientists in the energy transition
is to better communicate the realities surrounding climate change.

In his keynote address at the 2022 NAE Annual Meeting, John Holdren (NAS), science advisor to President Barack Obama,[3] listed what he saw as the 10 key engineering challenges of the energy transition:

 1.  More efficient buildings and industrial processes

 2.  A more intelligent, more efficient electricity grid

 3.  Improved batteries, longer-term storage technology

 4.  More efficient photovoltaic cells

 5.  Improved hydrogen production, transport, storage

 6.  More durable and affordable fuel cells

 7.  Drop-in fluid biofuels from sustainably grown feedstocks that don’t compete with food and forests

 8.  CO2 capture and storage/reuse for fossil and biofuel electricity generation and industry

 9.  Advanced nuclear reactors with lower costs, high safety, and proliferation-resistant fuel cycles

10.  Practical fusion

Dr. Holdren concluded by emphasizing that the most critical role of engineers and scientists in the energy transition is to better communicate the realities surrounding climate change.

In this spirit, we planned this special issue of The Bridge. The articles examine various aspects of the 10 challenges listed above. To address them, we invited contributors who have practical experience in the energy field and whose careers have involved making or advising on decisions requiring large amounts of capital and human resources in the energy industry.

The energy transition poses immense challenges and offers enormous opportunities for engineers. One of the best analogies describing engineering’s role in the energy transition may be its role as a bridge—a well-designed, robust connection between what is and what has to be.

In addition to the authors, we thank the following for offering their objective assessment of the draft articles: Lindsay Anderson, Bhavik Bakshi, Julian Boggs, Nick Brown, Mike Corradini, Steve Csonka, Jeff Dagle, Mike Doherty, Wayne Eckerle, Rod Eggert, Tom Graedel, Steve Hartig, Eric Kaler, Brendan Kochunas, Tim Luce, Pierluigi Mancarella, Arun Majumdar, Mike McKellar, Hamed Mohsenian-Rad, David Peck, Stratos Pistikopoulos, Joe Powell, José Santiesteban, Ramteen Sioshansi, George Stephanopoulos, Gavin Towler, and John Wall. We also thank Cameron Fletcher for managing the project and John Anderson and Al Romig for their support and encouragement.


Clemens J, Aliakbari E. 2022. Moon race not an apt analogy for today’s energy transition. Fraser Institute, Apr 18.

Dolsak N, Prakash A. 2019. The New Deal or the -Manhattan Project: Historical analogies to imagine climate action. Forbes, Apr 5.

Shanks T. 2022. It’s time for a climate change version of the Manhattan Project. Defense News, Feb 23.


[1]  The question of whether the ship of Theseus is the same ship after all the wood planks have been replaced is a central one in philosophy but need not concern us here.

[2]  Bold denotes NAE membership.

[3]  Holdren is also the Teresa and John Heinz Research Professor of Environmental Policy and cochair of the Energy Technology Innovation Project at Harvard University’s Kennedy School of Government.


About the Author:Tom Degnan (NAE) is the Tony and Sarah Earley Professor in Energy and the Environment Emeritus, University of Notre Dame, and manager (ret.), Breakthrough and New Leads Generation, ExxonMobil Research and Engineering Co. Tim Lieuwen (NAE) is executive director of the Strategic Energy Institute, and Regents’ Professor and David S. Lewis Jr. Chair, School of Aerospace Engineering, Georgia Institute of Technology.