In Sapiens, Yuval Harari argues that energy is infinite, but given our current technological and economic limitations, we conclude that this is not realistic. We need to develop new technologies that are both energy-efficient and economically efficient, and this will take a long time.
According to Yuval Harari’s book Sapiens, Part 4, “The Scientific Revolution,” Chapter 17, “The Wheel of Industry – An Ocean of Energy,” the history of Sapiens, or human beings, has been characterized by the rapid growth of capitalism, which is attributed to the increase in the size of the pie. In other words, the size of the pie must continue to grow in order to continue progressing. It also states that the energy available to humans is infinite. To understand this, we first need to define ‘energy’. The dictionary definition of energy is the ability to physically do work. Energy can be broadly categorized into biological and chemical energy. However, in this article, we will not discuss biological energy sources such as horses and cows because they are outside the scope of energy as defined by Homo sapiens. Chemical energy can be interpreted as a substance with enthalpy. In this article, I will argue why chemical energy, as defined above, is finite for three reasons.
First, there is a limited amount of alternative energy currently available. Regarding solar energy, the most promising alternative energy source, Homo sapiens states that “the total amount of energy stored in all of Earth’s fossil fuels is negligible compared to the energy the sun sends us for free every day.” However, only a small fraction of the solar energy that reaches Earth is actually usable. Q CELLS’ Q.PEAK, which is said to be the most efficient solar cell ever developed, has an energy efficiency of only 18.3% (the maximum efficiency is said to be around 19.9%, but let’s consider it average), which is extremely low compared to the 70-80% energy efficiency of chlorophyll a in photosynthesis in plants, which is the example used in Homo sapiens. Solar energy is also very limited in terms of local conditions. You need a large area of land, preferably a plain, and clear weather is essential for sunlight to reach it. It’s easy to see that there aren’t many places on Earth that meet these conditions, so the above rationale is enough to explain the limited amount of alternative energy available.
Second, if an economically inefficient energy source is developed, it is very unlikely to become the main source of energy. Most countries on the planet adopt capitalist market logic as their economic policy, and it affects every aspect of our lives. The same is true in the energy sector: no matter how good an energy source is developed, if the opportunity cost of obtaining it is too high, no one will want to use it. Currently, the most commonly used energy source is fossil fuels, represented by gasoline, whose advantage is that it is cheap compared to the energy it provides. The enthalpy of combustion for a liter of gasoline purchased for $1,500 is known to be 34.8 MJ. If a new energy source costs less than $0.000043 to obtain 1 J of energy, it will rarely be used. Of course, there are arguments against this. For example, if a new energy source is offered as a solution to a problem that is perceived to be more serious, such as environmental or safety issues, people will be more likely to use it, even at the cost of additional economic losses. Evidence for this is that recent awareness of fine particulate matter from coal-fired power plants and old diesel vehicles has increased interest in new energy sources, and kerosene, which is cheaper than gasoline, has not yet become the most common energy source among fossil fuels. However, groups and individuals who are trying to create high value-added are more likely to rely on traditional energy sources for greater profits, and groups and individuals who are struggling economically are more likely to continue using traditional energy sources because of the risks associated with adopting new energy. For example, harvesting solar energy at a level that makes it usable for everyday use requires a large number of solar cells, which is prohibitively expensive for a single household. Of course, countries with green energy policies, such as Germany, offer subsidies to households that install solar cells, but this is only possible when the country has the economic power to do so, which is not the case in most countries. Therefore, new energy needs to be more economically efficient than traditional energy in order to be adopted by society as a whole.
Third, time is limited. “Homo sapiens states that there is an abundance of energy, and the rationale for this is “the knowledge necessary to find it and convert it to our needs.” Of course, solar energy is abundant, but as mentioned earlier, the current commercially available solar cells are only about 18.3% efficient. In order to use solar energy as a primary energy source like gasoline, the development of new solar cells is essential. These new solar cells must combine high energy efficiency with high economic efficiency. According to the Korea Institute of Energy Research (KIER), South Korea is currently developing silicon solar cells with an energy efficiency of 16-20%, but they have not been commercialized due to poor economic efficiency. The third-generation nano solar cells currently under development are expected to be similar in energy efficiency to silicon solar cells, but are about 1/1000th as efficient in terms of economic efficiency, and have great potential for commercialization. However, technological progress tends to be inversely proportional to time, so it will take a considerable amount of time to develop solar cells that are comparable to the energy efficiency of plants. Therefore, a lot of time is needed before solar energy can be used as a primary energy source, and if it cannot be used as a primary energy source before petroleum fuels are depleted, humanity will face a severe energy crisis in the interim. If we also consider the time it will take to expand and supplement the existing gasoline-centered infrastructure with solar energy, we can conclude that the development of solar energy as a primary energy source must be accelerated.
From the above three arguments, we can conclude that the energy available at this point in time is finite. Of course, we’ve only considered solar energy as an alternative to primary energy sources like gasoline, but that’s because it’s the most fungible of the existing energy sources, and it’s possible that new energy sources could be developed to replace gasoline. However, it is not appropriate to consider something that has not yet occurred as a variable, so we have excluded it from the argument. Therefore, for now, we have a finite amount of energy available, and we should conserve energy to prepare for future uncertainties, while also developing technologies to prepare for the new era.
