💡 What Future Energy Revolutions Do We Need?

What Can We Expect About Them?

Last week, we discussed all the main energy revolutions in human history. We saw that better energy forms replace outdated ones. 

Source: Historical energy transitions: Speed, prices and system transformation, Fouquet 2016

So it seems like we/ve all but eliminated wood and coal, but we’re still dependent on oil and gas, right?

Uh oh. The truth is that we’re still near peak consumption of wood, coal, and oil—and gas consumption is exploding. That’s because even though they’re reducing as a share of the energy consumed, we’re consuming much more energy.

We know that we need to transition out of this paradigm as fast as possible. So what will happen?

1. Energy Sources

We mentioned in the previous article that all early energy sources boiled down to the Sun. But this is not true anymore. As far as we know, there are fundamentally four: the Sun, the Earth, the Moon, and atoms.

As we’ve seen, humanity has made huge steps forward every time it has found a new way to harness more energy: animal husbandry, watermills, sails, coal…

If we want humanity to move to the next level of progress, we need to increase the energy we harness. Energy is good. What’s bad is doing it in a way that has serious costs. Unfortunately, we’re not going in the right direction, not just because of the consumption of fossil fuels.

This is known as the Henry Adams Curve. Source.

Of course, this matches exactly the Great Stagnation of US productivity:

Note that this graph is logarithmic, while the previous one wasn’t. It’s made logarithmic to show that, before the 1970s, this was a line. A line in a logarthmic growth means exponential growth. Thanks to this, we can see we used to have a high exponential growth in productivity, and now it’s slowed down. This would match the fact that energy consumption was growing exponentially in the past, and is'n’t anymore in the US.

The slump in energy is not the sole culprit of the productivity slowdown, but it’s a contributer.

Energy use per person in the developed world used to follow an exponential, but has now dropped from it and has instead decreased.

Source

This is not good by itself: we like energy! We like using a lot of it! It warms us when we’re cold, freshens us up when we’re hot, illuminates darkness, powers our computers, and helps us do anything we want help with. 

What’s good about less energy consumption per person is that it means we pollute less. But this is forcing us to make an unfortunate tradeoff between using energy and the environment. It reduces our flourishing for the sake of sustainability. What if we didn’t need such a tradeoff? This is what the future of energy will need to deliver.

The schema from above tells us our energy options to achieve this. First, on the energy generation side:

• Solar—thermosolar or photovoltaic

• Wind

• Tidal

• Nuclear fission

• Nuclear fusion

• Geothermal

Of these, photovoltaic seems better than thermosolar, wind seems capped¹, fission is unpopular, fusion is far away, and both tidal and geothermal are pretty early-stage—although geothermal is very promising. Which means that our best bets right now are photovoltaic, wind, and nuclear fission. We must unlock some or all of them if we want humanity to reach the next level of prosperity².

However, it’s not only about sources. As we saw earlier this week with the value of electricity or combustion engines, there are other aspects of energy that are as important as the sources. What are they?

2. Energy Requirements

You don’t just want to generate energy and use it. You want to be able to transform it, store it, and transport it, in a way that is as easy, cheap, and clean as possible.

Transformation

It’s 10,000 BC. You and your band of 20 people live close to a huge forest. You want to build a mound.

Grave Creek Mound, in Moundsville, West Virginia. Source.

​​You have plenty of energy stored in these trees! But can you harness it to build that mound? No, because you don’t have a way to transform the Sun’s energy, stored chemically in those trees, into power to move soil around. You can’t even use the trees to feed people so they have more babies and the clan grows and eventually there’s enough muscle to build a mound. At most, you can burn some trees to cook food, and burn some of them to use the ash to fertilize the soil. But that’s an extremely inefficient way to transform trees into usable power! Muscle could do things that wood couldn’t.

Conversely, wood could do things that muscle couldn’t. When it was dark and cold, you couldn’t use the clan’s muscle energy to gain heat and light. At most you could all gather together for some heat, but that’s not very convenient and prevents anybody from working much. Light was simply impossible to get from muscle, you could only get it from wood.

In the past, people needed a specific source of energy for every type of use. That’s inconvenient. So technologies to transform energy from one form to another were very useful.

Domesticated animals were an early way to do that, converting energy from plants into flexible power, food, and transportation.

Ovens allowed us to transform heat into industrial processes. 

The combustion engine allowed us to transform the chemical energy stored into fossil fuels into transportation energy.

The biggest breakthrough was arguably the steam engine: it allowed us to transform heat into many types of transportation and power uses. You could use it to power trains, steamboats, or any type of machine.

This is also one of the core reasons why electricity is so valuable. It’s not a source or a use of power. It’s an intermediary. But it’s extremely versatile: you can convert nearly any source of energy into electricity, and then you can use electricity for nearly all use cases.

Transportation

Electricity is also valuable because of a nearly magical aspect: it allows us to instantaneously³ transport energy very far away⁴ through cables. 

As we said last week, the importance of energy transportation was the reason why trees had to be placed so close to cities, or why it took so long for coal to be widely used for heat.

It’s also one of the reasons that oil replaced coal: as a liquid, it’s much easier to transport through pipelines—impossible for coal. Similarly, one of the reasons why the combustion engine is superior to the steam engine is because oil can be filled in a tank much more easily than feeding coal into a furnace. 

So we need our energy to be easily transformable and transportable. In both of these, electricity shines. 

What else?

Storage

Storage of energy has always been a problem. For example, in the 19th century Mississippi Valley, corn was converted into bourbon or ham so it would not spoil (“so that there are no losses of the energy it contains in the form of food”). Whisky also had the advantages of having more calories per unit of weight, so it was more transportable. This was valuable when the cost of transportation was so high, before railroads.

If we go back to our main types of energy though, one of the huge upsides of wood and coal is how easy they are to store: just drop them somewhere dry. 

Sun and wind can’t be stored at all, whereas water is the most storable type of energy: just dam it.

Oil needs tankers, and gas needs to be frozen to be compressed, or else plugged into huge, unwieldy storages. But they’re doable. That’s why countries have strategic reserves of the stuff, but only a few months worth.

The need for storage is connected to the need for availability. You want your energy when you need to use it, not at another time. If you need to wait for the energy to be available, you waste your time. It’s been the bane of sailors or millers waiting for wind, of car drivers having to go to the gas station to get more gas, horse riders having to wait for horses to eat and rest, or solar plants waiting for the Sun to rise.

Since you can store oil and gas, they’re available whenever you need them. 

Electricity is the trickiest. It needs batteries to be conserved, which are notoriously hard and expensive to build. But at least electricity is storable in a way that renewable energies like wind and solar are not, which is why we transform them into electricity before storing them. Nevertheless:

This is the famous Duck Curve, something that most countries will have to contend with sooner or later. It basically shows the amount of energy needed during different hours of the day in California in Spring, excluding solar and wind. As you can see, at night, California needs around 15-20 GW. But around the middle of the day, it has needed less and less energy every year. So much so that now, during peak solar generation hours, there’s more energy generated than consumed. This is problematic, because it means that adding more solar energy doesn’t help much, and that every new solar energy installation will actually reduce the money earned by existing solar operators. This is all because we can’t easily store solar energy. 

But at least, we can already use batteries to save energy overnight. It’s expensive, and we lose some of it, but we can do it. That puts us in a similar position as gas lighting vs electric lighting: while DC electricity was expensive and had losses, it was not very competitive against gas. But when AC electricity replaced it, electricity losses dropped, electric lighting became much cheaper than gas lighting, and it finally replaced it. 

Unfortunately, we have a much bigger problem for seasonal storage. We can have all the Sun we want in June, but if we don’t have much in December, we will still need other energies.

What does this tell us? That if we want a new energy revolution, we need a very cheap way to store electricity. This clearly means that batteries need to continue improving fast for overnight electricity storage. We still need cheap seasonal storage. This will be the key technology that fully unleashes the combo of solar and electricity.

One more thing that’s relevant about storage is how we’re consuming electricity.

Heat has gone down, and lighting accounts for very little of the overall energy. We would want more electricity for industrial power, and as we can see, energy for transportation keeps growing. 

This means we need to keep in mind that figuring out how to store energy for transportation is crucial.

Energy Density

Which brings up another issue, energy density, connected to both energy storage and transportation.

Since it’s expensive to move energy around, you want energy as dense as possible, so a few grams of something give you a lot of power.

This is the reason why kerosene is so common in aviation: it packs a ton of energy per kilogram, and when you’re flying, every kilogram matters because it costs a lot of energy to keep the plane flying. That’s why about 30-45% of a jet’s weight is its fuel (fuel fraction). It’s an even bigger consideration in rockets, with a fuel fraction over 90%⁵.

This matters less in cars because only 5% or less of the car’s weight is usually fuel. But this is not true for electric cars, whose batteries are about 25% of the weight of the car.

Indeed, transporting tethered electricity is easy and cheap with power lines. But the moment you need to untether something, you hit the problem of energy density. This is why electric rockets, or even planes, are a pipe’s dream today: in most cases, the batteries will be too heavy to carry themselves.

Cheap Cost

What we see is that new energies never replaced older ones until they were cheaper:

• Coal didn’t replace wood until the transportation costs reduced enough to make it cheaper.

• Coal took many decades to replace wind, because wind was free. It took many other advantages to overcome this cost difference. And it only happened when the cost-benefit proved positive: when traders noticed that the availability and flexibility of steam engines allowed trade opportunities hard to access for sailboats.

• Gas lighting took time to replace candles because it required an upfront investment. Companies could afford it, and were the first ones to do it. But it first entered the richer households before trickling down.

• Electric lighting didn’t replace gas lighting until AC current made it cheaper.

• The moment the combustion engine became cheaper than the steam engine, it replaced it. Not before.

In other words: we can fear climate change all we want, but the only thing that will really make a difference is not public action. It’s the cost of energy that doesn’t emit CO₂ dropping below that of fossil fuels.

Interestingly, we can also predict that from now on, heat pumps will start replacing gas heating. Unfortunately, this requires changes in household and industrial installations. This requires an upfront cost, and that will delay it, the same way as it took time for electricity to replace gas lighting because it required new electrical wiring in homes. However, if energy sources become even cheaper, the gap with gas heating might become so huge as to make the investment a no-brainer.

Easy to Use

This is another thing that tilts one technology against another. Electric lighting is much easier to handle than candles or burning from gas. Throwing coal into the steam engine is easier than handling complex sails. You can buy fodder for your horse, carry it home, give it to your horse every few hours, clean your horse, care for it, call the vet… Or you can plug the nozzle into your car tank.

Here, we have a clear winner again: electricity.

On the generation side, difficulty is one of the main downsides of nuclear energy: it’s dangerous, so it needs a lot of proactive management, which brings costs up. Meanwhile, oil is especially easy to handle, one of the reasons it’s everywhere.

Cleanliness

If a type of energy is cheap but dirty, people will consume it: in most cases, they would rather save money than their health⁶ or the environment.

A worker adds plastic to a furnace. Credit...Ulet Ifansasti for The New York Times.

But as costs of different energies become comparable, cleanliness becomes important again. The dark spots of candle and gas combustion were a good reason for the switch to electric lighting.

Conclusion

Here’s what we know:

• Energy consumption is slowing down in developed countries. This is good for the environment but bad for economic progress. If we want people to have limitless opportunities, we need to increase energy consumption.

• However, we need to do it in a way that makes the Earth not worse off, but better. A world of more energy and more sustainability.

• Luckily, the three sources of energy that we can rely on don’t emit CO₂: wind, solar, and nuclear. We need to push them all, but especially the most promising one (solar) and the most unpopular one (nuclear).

• We’ve already invented the perfect intermediary for energy: electricity. It’s cheap to transform and transport, it’s easy to use, and clean. Its major downside is storage.

• Unfortunately, this is also a weakness of the three most promising energy sources we have. Nuclear energy can be stored, but it’s hard to ramp its generation up and down. Meanwhile, solar and wind can’t be stored. This means that supply and demand can’t easily meet. The only way to solve this is with better storage.

• The biggest mismatches between supply and demand are the daily peaks and valleys of demand, compared to the daily and seasonal peaks of wind and solar. 

• This means we absolutely need to figure out overnight electric storage. Batteries are our best bet for that. We need that technology to progress as fast as possible.

• This is especially true for transportation. It’s great that Tesla is leading the way here.

• But electric batteries are unlikely to work for ships and especially airplanes. We need another way to store energy for them.

• We still need a way to solve the mismatch of supply and demand of energy across seasons⁷.

In other words: We need to dramatically reduce the cost of nuclear energy, solar energy, overnight battery storage of electricity, and seasonal energy storage⁸. Without all four of them, it will be hard for humanity to thrive by moving to the next level of energy consumption. 

I will be writing on all of these, so stay tuned!

1. There’s still plenty of wind power available, but not as much as solar, and solar is becoming cheaper faster than wind. Total potential wind energy is just 5x the 2007 world consumption according to these papers: Lu X., McElroy M.B., and Kiviluoma J.: Global potential for wind-generated electricity; Archer C.L. and Jacobson M.Z.: Evaluation of global wind power. Meanwhile, solar is 30x. We would run out of energy this century if we only had wind. It would get us to next century with solar.

2. I’ll write more about all of them in the future.

3. Not actually instantaneously, but close to the speed of light.

4. You just need to increase its voltage to reduce its losses.

5. From what I can gather on sites like this or this. ChatGPT and Edge’s AI agree.

6. As long as the impact is long-term.

7. Some options: interseasonal batteries, global transmission, energy that’s so cheap to produce that we can overproduce it to match any demand, space generation and Earth beaming, transform CO2 into methane… I’ll explore some of these in the future.

8. Three of these are technical issues, and the 4th is social. The technical issues don’t need much support beyond investing and working in them. The 4th—nuclear—is a social and communication issue that needs something else.