In response to global warming, countries all over the world have been devising plans for a transition to clean energy sources. But how much of this clean energy will we need in, say, 2050? Much hinges on getting this question right. What infrastructure should we build to generate the desired amount of energy? How much transmission and storage capacity should we prepare for? And how many new mining projects should we license?
Many politicians, scientists and climate activists envisage a future in which people use dramatically less energy. This assumption undergirds the climate plans of many European countries and the scenario studies that guide their long-term policies. Organisations like Fraunhofer and Agora Energiewende in Germany; Berenschot-Kalavastha in the Netherlands; IE-Net, Bond Beter Leefmilieu and Energyville in Belgium and RTE in France assume that final energy use will—or should—sharply decline over the coming decades. Some scenarios even advocate a 50% reduction. In its recently published Net-Zero scenario, the International Energy Agency (IEA) aims for an absolute reduction in global energy demand by 2050.
And it’s not just rich industrialised nations that are implicated. A recent study by the Oxford Martin School, which has been enthusiastically received by advocates of renewables, proposes a “fast transition” to renewable energy combined with a decline in final energy demands globally—including in poor countries—by 2045. Indeed, the notion that the best energy is the energy not consumed has become a popular meme—not just among environmentalists and climate activists, but among leading politicians like French president Emmanuel Macron, EU climate czar Frans Timmermans and energy multinationals like EDF. Even the IEA has called energy efficiency “the world’s first fuel.”
At first blush, reducing our energy consumption seems sensible. We can increase efficiency a great deal by, for example, insulating homes, installing heat pumps and making vehicles more efficient. We can also change our behaviour and adopt practices that waste less energy, such as sharing cars and riding electric bicycles. Electrifying road transport will greatly reduce energy waste in the form of heat loss. If we replaced all the internal combustion engines in our cars and trucks with batteries, road transportation would require far less energy than it does today, while providing the same levels of comfort. This is all good news, although we should be mindful of Jevons’ paradox: higher efficiency can lead to higher energy demand. For instance, in the early stages of the industrial revolution, more efficient steam engines led to greater use of coal and led to an overall increase in energy use, not a decrease.
Yet, even if we can somehow avoid Jevons’ paradox, planning for an overall reduction in energy supply is still wrongheaded, not just for poor countries, but for rich ones, too. If we want future generations to flourish and meet ambitious climate targets, we will need more energy, not less.
First, there’s an important downside to electrification: although it will indeed lower heat losses, it will also drastically increase the need for energy storage, especially when combined with the expansion of wind and solar energy. To decarbonize long-distance transport by water, road and air, we are also likely to need huge amounts of synthetic fuel. But producing synthetic fuel—and reconverting some of it into electricity—involves substantial transformation losses, which could cancel out many of the gains from electrification itself. For instance, the Agora Energiewende 2045 scenario for Germany projects a demand of 422 Terawatthours (TWh) of synthetic fuels (in the form of power-to-liquid and hydrogen) by 2045, of which 326 TWh will need to be imported. By comparison, Germany’s current total annual power production is around 550 TWh. We will also need large amounts of clean energy to produce hydrogen for fertilizer production and other industrial processes.
And, in fact, reducing our future energy supply is not even a desirable aim. Instead, we should be increasing it. The past centuries of human progress have been dependent on increasing energy use as we have moved from human and animal labour to water and wind energy; from water and wind to coal; and from coal to oil and gas. There is little reason to think that future achievements will not also require more energy: it is energy that enables us human beings to modify our environment, to fight the continuous battle against the second law of thermodynamics (the rise in disorder or entropy), and to provide services and products that increase our well-being. Greater energy supplies have also enabled unprecedented increases in human populations. In the future, energy could be used in many new ways that would be highly beneficial to human society.
Promising candidates for beneficial energy use include vertical farming and precision fermentation, which could replace animal-based food and drastically reduce the environmental footprint of agriculture. But vertical farming requires more energy input than our current agricultural practices, in the same way that the mechanized agriculture developed in the nineteenth century required more energy input than pre-industrial farming (which mainly relied on human and animal muscle power).
The large-scale desalination of seawater could also dramatically alleviate the ecological pressures caused partly by anthropogenic global warming and help both human societies and ecosystems to become more climate-resilient. Desalination is a mature technology and is already used at scale in California and the Arabian Peninsula, but, again, it requires lots of (clean) energy.
We will also need more energy to fulfil our climate goals. The IPCC scenarios that manage to limit warming to 1.5°C require 100–1000 gigatonnes of carbon removal by 2100. Nature-based solutions like trees and algae can only supply a small fraction of these “negative emissions”—the lion’s share will have to come from artificial carbon removal. This translates to a draw-down industry on a scale approaching that of the current global oil extraction industry. The processes involved either require huge tracts of land (e.g., bioenergy combined with carbon capture, known as BECCS); enormous amounts of energy (e.g., direct air capture) or both (e.g., enhanced mineralization of silicate rocks).
The best energy is not the energy we don’t consume, but the energy that we use to improve the welfare of humanity and perhaps that of other sentient beings on this planet. We are very far from obtaining as much energy as we could fruitfully use to further these goals. Besides, many industrialised democracies need to welcome more immigrants, to compensate for their aging populations and declining birth rates. This will also require more energy.
But what if it is simply not feasible to produce clean energy on a sufficient scale? There is no physical law that prohibits humanity from generating much more clean energy than we do today, but some countries have made this unnecessarily difficult by narrowing their technological options and rejecting nuclear power for ideological reasons. If industrialized countries insist on relying exclusively on renewable energy sources, they will quickly encounter geographical limitations and resource bottlenecks. It is no coincidence that plans for a 100% renewable future are often coupled with calls for energy reduction: there is only so much solar and wind energy that you can harvest per square metre. This is also why, even after reducing energy demands, scenario studies typically still assume large-scale imports from sun- and wind-rich countries in Africa and the Arab peninsula. But apart from the fact that the economic feasibility of such imports is doubtful, these are poor countries that consume very little energy, clean or otherwise. They may want to use their clean energy supplies themselves to develop their societies, rather than exporting them.
It would be much wiser to bet on a wide variety of energy technologies, including nuclear energy, which has a very high energy density and uses few resources. It is impossible to predict the future, but a diverse energy portfolio will surely increase our chances of success. We need to construct more energy infrastructure, increase domestic mining of critical minerals and convince the public of the benefits of an energy-rich future. If people appreciated how useful it would be to have more energy, rather than constantly being told that they should use less energy, they would probably be more enthusiastic about contributing to the energy transition and happier about living near the infrastructure that enables it.