This blog post examines whether the concept of infinite energy discussed by Yuval Harari in Sapiens is realistically achievable given current technological and economic conditions.
According to Chapter 17, “The Wheel of Industry – The Sea of Energy,” in Part IV, ‘The Scientific Revolution,’ of Yuval Noah Harari’s book Sapiens, the history of Sapiens, or humans, experienced rapid growth due to the development of capitalism, which is attributed to the expansion of the size of the pie. In other words, for sustained development, the size of the pie must continue to grow. It also states that the energy available to humans is infinite. To understand this, we first need to define ‘energy’. Dictionary definitions describe energy as the physical capacity to do work. Energy can broadly be categorized into biological energy and chemical energy. However, this article excludes biological energy sources like horses and oxen from discussion, as they fall outside the scope of energy as defined in Sapiens. Chemical energy can be interpreted as substances possessing enthalpy. This article will argue why chemical energy, defined as above, is finite, based on three reasons.
First, the amount of currently available alternative energy is limited. Regarding solar energy, considered the most promising alternative, Sapiens states: “The total energy stored in all of Earth’s fossil fuels is negligible compared to the energy the Sun sends us for free every day.” However, the amount of solar energy actually usable upon reaching Earth is very small. Among currently developed solar cells, Hanwha Q CELLS’ Q.PEAK product is known for the highest efficiency (though its maximum efficiency is reported to be about 19.9%, we will consider average energy efficiency). PEAK product, for instance, has an energy efficiency of only about 18.3% (though maximum efficiency is known to be around 19.9%, we’ll consider the average energy efficiency). This is an extremely low figure compared to the 70-80% energy efficiency of chlorophyll a acting as a battery in photosynthesis, as cited in Sapiens. Furthermore, solar energy is severely limited by regional conditions. It requires vast, flat land, and clear weather is essential for sunlight to reach that land. It’s easy to see that few places on Earth meet these conditions. Therefore, based on the above reasoning, it can be sufficiently explained that the amount of usable alternative energy is limited.
Second, if an economically inefficient energy source is developed, it is highly unlikely to become a primary energy source. Most nations on Earth adopt capitalist market logic as their economic policy, which influences every aspect of our lives. The energy sector is no exception. No matter how promising an energy source may be, if the opportunity cost of obtaining it is too high, no one will choose to use it. The most widely used energy source today is fossil fuel, represented by gasoline. The advantage of gasoline is its low price relative to the energy it provides. It is known that purchasing 1 liter of gasoline for 1,500 won yields a combustion enthalpy of 34.8 MJ. If the cost to obtain 1 J of energy from a new energy source cannot be reduced to 0.000043 won or less, that new energy source will likely see little use. Of course, there is room for counterarguments. For instance, if a new energy source is proposed as a solution to a problem deemed more severe—even if it entails additional economic losses like environmental or safety issues—many people would likely seek to utilize it. Evidence supporting this includes the growing awareness of fine dust pollution from coal-fired power plants and aging diesel vehicles, which has increased interest in new energy sources. Another point is that kerosene, despite being cheaper than gasoline, has not become the most common fossil fuel source, surpassing gasoline. However, groups or individuals seeking to generate high added value are likely to rely on existing energy sources for greater profits. Similarly, groups or individuals facing economic hardship are likely to continue using existing energy due to the significant risks associated with adopting new energy. For instance, harnessing solar energy to a level usable in daily life requires a large number of solar panels, which is prohibitively expensive for a single household. While countries like Germany, which pursue eco-friendly energy policies, provide subsidies to households installing solar panels, this is only feasible when backed by national economic strength and is difficult for the vast majority of countries. Therefore, for new energy to be adopted across society, it must be economically more efficient than existing energy sources.
Third, time is limited. Sapiens describes energy as abundantly sufficient, citing “the knowledge required to discover energy and convert it to suit our needs” as its basis. Solar energy is indeed plentiful. However, as mentioned earlier, the efficiency of currently commercialized solar panels is only about 18.3%. To use solar energy as a primary source like gasoline, developing new photovoltaic cells is essential. These new cells must possess both high energy efficiency and high economic efficiency. According to the Korea Institute of Energy Research (KIER), South Korea is currently developing silicon solar cells with 16-20% energy efficiency, but they have not been commercialized due to poor economic efficiency. Third-generation nano solar cells currently under development are expected to have energy efficiency comparable to silicon solar cells. However, in terms of economic efficiency, they show approximately 1/1000th the cost, making their commercialization highly probable. Nevertheless, technological advancement tends to be inversely proportional to time. Therefore, developing solar cells with energy efficiency levels similar to plants is expected to take considerable time. Therefore, transitioning to solar energy as the primary energy source requires considerable time. If humanity fails to establish solar energy as the main source before petroleum fuels deplete, we will face a severe energy crisis during the interim period. Furthermore, considering the additional time needed to expand and supplement existing gasoline-centric infrastructure to accommodate solar energy, it becomes clear that development efforts must accelerate significantly to achieve this goal.
Based on the three grounds above, we can conclude that currently available energy is finite. Of course, we considered only solar energy as a replacement for primary energy sources like gasoline, but this was based on the judgment that it has the highest potential for replacement among existing energy sources; new energy sources could be developed to replace gasoline. However, considering variables that have not yet occurred is inappropriate, so they were excluded from the argument. Therefore, for now, available energy is finite. To prepare for future uncertainties, we must conserve energy and simultaneously strive to develop technologies for the new era.
