Energy powers everything we do, and for most of humanity's 300,000-year history, that energy has come from boring old biomass. Grains, nuts, berries, and meat fueled our muscles. Wood burned in fires. All the way up to 1850, biomass provided more than 90% of the estimated 7,791 terawatt hours (TWh) of energy we consumed in a year. Then fossil fuels swiftly took over. Coal, oil, and natural gas now account for three-quarters of humanity's annual 183,230 TWh of energy use. Renewables, hydrogen, and nuclear may start to take the reins from here, but it's far too early to say.

Naysayers have had no such uncertainty over the years. After the iron-making blast furnace arrived in Medieval Europe, foretellers forecast that forests would disappear due to the furnaces' insatiable appetites for fuel, abetted by humans' hunger for iron. More recently, confident prophets have repeatedly predicted that we would run out of oil, a peak which still hasn't arrived.

Mark P. Mills, a contributing editor at City Journal and the executive director of the National Center for Energy Analytics, along with his co-author, Peter W. Huber, a  senior fellow at the Manhattan Institute and a prominent pro-science lawyer, explained why energy naysayers have consistently been wrong in their 2005 book, The Bottomless Well: The Twilight of Fuel, the Virtue of Waste, and Why We Will Never Run Out of Energy. The duo even went further and claimed that the naysayers will always be wrong. "Energy supplies are infinite," they wrote.

The Bottomless Well was much more than a takedown of doomsayers. Mills and Huber explained energy and thermodynamics in a refreshingly accessible way, and issued their own future forecasts, which – for the most part – were surprisingly prescient. Twenty years later, as energy transitions in the midst of a changing climate dominate discourse, their book remains timely and informative.

I recently caught up with Mark Mills. (Sadly, his co-author and close friend, Peter Huber, passed away in 2021.) In part one of our interview, Mark checked in on some of his forecasts from twenty years ago, and I picked his brain on current energy issues and asked him whether energy on Earth still remains effectively infinite.

RP: In a 2006 update to your book, you wrote that “we can economically dig, dam, pump, and purify all the energy we like. If we choose to.” Is that still true twenty years later?

MM: For all practical human purposes, energy is infinite. We don’t produce energy. We capture it and convert it. So the whole thesis of the book was to try to reorient people’s thinking about the physics and the thermodynamics. But you couldn’t say that because nobody would buy a book about physics and thermodynamics. It’s about understanding how the universe works – building machines to tap into forces to deliver useful power to animate things, and we call that energy.

I worked in semiconductors – my first job. In semiconductor manufacturing, your goal in the fab is not to make computer chips smaller. That wasn’t the goal. That was the consequence of trying to get more energy out of the logic operation. And small switches use less energy than big switches. So you were chasing down to the bottom of the Bottomless Well.

Richard Feynman noted that there’s 'room at the bottom’. As you chase things to the bottom of the structure of the universe, you keep discovering new things.

The name of the book was also about the debates at the time. When the book came out in 2005 was the peak year for peak oil theory. The whole intelligentsia and the media were babbling about running out of oil. Maybe five to ten percent of the book is about oil – that’s not really what it was about.

RP: So I understand the point about there being infinite energy in the universe, but what about here on Earth. Is there practically infinite energy here as well?

MM: For all practical purposes all of the energy forms that we want to tap are essentially infinite supply. The fact that that the sun will last four billion years is completely irrelevant. The fact that sunlight is free is irrelevant. Oil is free, too. Nobody pays for oil. Coal is free. Moving air, moving water – it’s all free. You pay for access to land and materials to build machines to convert natural forces into useful power. Those are the things that determine the utility of delivering power, and the cost of those things in dollar terms, in land use terms, and the cost of the physical materials used to build machines are the practically limited resources. Those three things determine whether an energy modality has legs. Wind and solar are inherently poorer than hydrocarbons by all three measures. They use more land, materials, and money to deliver the same amount of energy.

We chose not to write our book saying that, because it triggers the biases in people’s heads. Our goal was to take people gently into the light of truth and reality and physics.

RP: You talked about a breakthrough that could change everything: efficient electrolysis of water via solar power. “Silicon and hydrogen will completely displace uranium and carbon,” you wrote. Where are we on the quest for this holy grail?

MM: At the time, we were very bullish on hydrogen – more bullish then than we are now. I thought better catalysts were around the corner. If you can trick water with better catalysts to get hydrogen out of it, it would be really magical. But we completely failed at catalysis and electrolysis. I’m still optimistic that with AI and supercomputers, we can solve the problem.

Atomic phenomena will ultimately displace most combustion phenomena. By atomic I mean the magic of how you do catalysis, fission, fusion, the photoelectric effect, etc. Those will unlock radical changes in our footprint on Earth. But they’re really hard engineering problems to solve. Meanwhile, we’re getting better and better at the engineering and physics of combustion – astonishingly good. We’re a long way away from thermodynamic limits with combustion. As long as you have headroom there, you can keep lowering costs.

RP:  “The transition to the hybrid electric car will be completed over the next two decades,” you wrote. Why hasn’t this happened yet? Hybrids represent about 20% of cars sold today.

MM: Hybrid drive is much better – more energy efficient, much better, more flexible. You get the best of the silicon world and the best of the combustion world, mediated through a computer. The reason we missed it was because we did not anticipate the insanity of subsidizing EVs. If you had left the industry alone and it pursued the optimal technology path for drive trains then the obviousness of hybridization that is now taking off would have taken off ten years ago. We would have got it right in terms of the technology trajectory. Our forecast was delayed  because of interference forcing people to use battery all-electric in all applications. 

RP: In 2005, you described two main schools of thought as to how we reduce our impact on Earth’s systems: cornucopians and lethargists. The first camp advocated for improved efficiency, the latter advocated for simply using less. Twenty years later, do you think there is a new school of thought?

MM: The transitionists. The idea of an energy transition is silly. We keep using and repurposing old phenomenologies with new knowledge, including stone. We not only still use stone, we use more of it than ever in human history. What we do different now is we cut it better and more efficiently, we move it more efficiently. The same is true of wood. We do better at using it, harvesting it. We can put wood chips into polymers, make boards out of waste. The transitionists deserve a special label because they believe in something that’s equally silly as the lethargists and cornucopians.

Cornucopians are the camp that’s saying that we can have what we want by being more efficient because there’s so much waste. They’re wrong because what is often thought of as waste isn’t really waste. There’s an economic decision attached to choosing lower thermodynamic efficiency, because what you’re choosing to do in using the more energy-wasteful machine is a trade for some other attribute in society, say your time, or your money. More efficient technologies that cost more sacrifice money that people might rather use elsewhere, and that may have a higher value. Waste is a decision to harvest other attributes. What we call waste is also a thermodynamic necessity, a price we pay to create machines and phenomena like lasers, and even computers. This is, to use the physics terms, the cost of avoiding entropy and disorder.

And then you have the lethargists. These are people who advocate for zero-net population growth, degrowth etc. They think we need to be more abstemious. They’re wrong, but not for a physics reason. They’re wrong because of the fundamental nature of humanity and civilization.

What is the viewpoint we were trying to put in our book? We couldn’t come up with a word, but we are realists. I’ve modified it since. I tell people that we are realistic optimists. I’m saying that the physics of the universe we live in… gives you reason to be optimistic. We will never run out of energy. We can cause ourselves to run out of energy through pure stupidity. Human beings can distort the system.

RP: You were spectacularly wrong about rising U.S. electricity consumption in 2005. You said it would rise another 20-30% over the next ten years. It remained essentially flat for 15 years. Why were you so wrong? Did that disprove your point about efficiency?

MM: We began exporting our manufacturing contemporaneous with writing the book – call it the China effect. If the share of the U.S. economy that was in manufacturing today was the same as then, then not only would we have decisively captured all of the new technologies, but the demand for electricity would have been about 20% higher than it is today. The other thing that flattened electricity demand: LEDs took over much faster than we predicted.

Let’s look at today: The electric demand curve is going to tilt up aggressively, for two reasons. Because we’re not going to give up manufacturing anymore. But more importantly, we have harvested the one-time gains in efficiency from LEDs, refrigeration, and air-conditioning. Any new demand – digital, EVs – will push the curve back up.

RP: There's been some pushback over AI's massive energy use. Do you think it's worth the electrons?

MM: The hype over AI is well-placed. It is a phenomenology that’s foundationally different. Inferential machines are different than calculation machines. It’s a big deal and it will be a big deal for a long time. Because we have infinite supplies of energy to power it, we can take advantage of it. It will be less power-hungry in the future, which is good, because then we’ll do more of it.

Imagine it’s 1935 or so, when the aviation era really started to take off, and everybody got together to talk about the benefits of flying versus taking a ship, and the principle thing they talked about was whether or not we had enough fuel to power all the airplanes. They say let’s not build the airplanes as quickly because we might not have enough oil to power them. No. What we did in the market was to try to find the fuel and the engines to make it work. Since then, airplanes became 500% more efficient in terms of BTUs per passenger mile. AI will vastly exceed those efficiency gains. It will also vastly exceed aviation’s energy demands.

(Watch for part two of my interview with Mark Mills this weekend.)