Solar stocks and solar flows

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Our current society, technology, and well-being were, in the 20th century, built with fossil fuels as their power source. Fossil fuels are “solar stores”, solar energy stored for hundreds of millions of years. Fossil fuels can be considered nature’s brilliant technology for highly efficient and sustainable energy storage.

The fabric and nature of present-day society appears to be closely tied to the properties of these solar stocks. This implies that society as we know it cannot be sustained without solar stocks and fossil fuels.

Solar Stocks in Today’s Society

Let’s look at the characteristics of solar stocks (fossil fuels) and society today. Fossil fuels are currently abundantly available, reliable, adaptable to demand, compact, easily transportable and easily stored. This is largely due to their extremely high volumetric energy density of around 35 gigajoules per cubic meter (in liquid or solid form). This extremely high value allows a full passenger car weighing 2000 kg to travel 1000 km at 120 km/h on 50 liters of petrol or diesel. It also allows the Netherlands to acquire and store enough natural gas to last an entire winter.

These examples illustrate the characteristics and requirements of today’s society: continuity, reliability, cost and time efficiency, and comfort for all people and businesses. Fossil fuels respond well to these demands, and the reverse seems to be true: availability creates demand, and our modern demands have been developed based on the availability and characteristics of fossil fuels. This close interconnection between today’s societal demands and the characteristics of fossil fuels is crucial for future energy policies.

Solar fluxes in today’s society

Solar fluxes, ie the energy that the sun deposits on earth in real time today and tomorrow, can be exploited by different means: wind turbines, photovoltaic solar panels, solar thermal panels, hydroelectricity and biomass. Other energy modalities, such as geothermal, tidal, and nuclear, originate from within the earth and are not based on solar fluxes.

Current energy policies are mainly based on replacing solar stocks with solar flows: fossil fuels are out, and wind, solar, biomass and hydro are in. Nuclear is controversial and, in any case, not enough, and geothermal and tidal energy are too limited geographically. worldwide. The fact that current energy policies are mainly based on solar fluxes is very remarkable, since the characteristics of solar fluxes do not correspond well to current societal requirements (continuity, reliability, efficiency in terms of cost and time, and comfort for all people and businesses).

Characteristics of solar fluxes

Wind and sun operate anywhere on earth but are intermittent and unpredictable on an hourly and daily basis. This very nature of wind and solar power is incompatible with societal demands for continuity and reliability. On the other hand, hydroelectricity and biomass respond better to these demands, but fail on geographical limits and environmental impact: hydroelectricity requires significant height differences in specific geographical circumstances, and biomass costs a lot too much natural land space and biodiversity.
Moreover, not all solar fluxes have the main property of solar stocks: a high volumetric energy density. A cubic meter of moving air or water, or a square meter of solar radiation, contains less than 1% of the energy of a cubic meter of liquid or solid fossil fuel. This is why solar fluxes require so much space and materials to be exploited. The much-used argument that abundant solar fluxes are as valid as they are irrelevant. Abundance is not the critical success factor. Energy density, continuity, reliability and profitability are the critical success factors of our current society. In other words, it is not the amount of energy that matters but what is needed to harness and use it. The latter is mainly determined by the energy density.

Scientific analysis

The Technical University of Eindhoven has correlated the energy density of our energy sources with the evolution of our civilization. For thousands of years, we have gone from human energy (galley slaves and porters) to animal energy (oxen and horses), to wind energy (galleons and windmills), to water energy ( water mills and reservoirs), fossil fuels (coal, oil and gas) and nuclear energy (uranium and plutonium). At each stage, the energy density and, therefore, our societal development has increased more than tenfold. A horse replaces more than ten humans, propelling plows and wagons. A windmill replaces more than ten horses, powering land reclamation from the sea. A fossil fuel power plant replaces hundreds of wind turbines, powering households, public transport and industries. And one tonne of nuclear fuel replaces more than 50,000 tonnes of fossil fuel, reducing energy waste streams to very small volumes with low environmental impact.

The essence of energy density

The intrinsic energy density of solar stocks and fluxes is a physical characteristic that no technology or innovation can influence. We can, for example, concentrate sunlight in one place with a magnifying glass or an array of mirrors, but the total space required to harvest a certain amount of energy cannot be decreased. For example, the mirror array of a concentrated solar power plant must have a similar surface area to that of an array of solar panels producing the same amount of energy. By using a hydroelectric reservoir, we can also concentrate the potential energy of an entire river basin in one place. But the surface of such a reservoir must be very large, which destroys part of the natural basin.

Low Density Solar Fluxes in a High Density Society

This implies that the intrinsic energy density of an energy source – that is, the original energy content per square meter or cubic meter – is directly correlated to its potential to sustain our current energy-based society. technology and energy-dense. Our cities, industries, agriculture, transportation, and data centers require large amounts of electricity and energy in a small space, and this cannot be done efficiently with low-density solar fluxes that require large amounts of space (and also large amounts of materials, often rare materials like lithium, cobalt, copper, and neodymium). Harnessing solar flux – through solar panels, wind turbines, hydroelectric plants and biomass farms – cannot be miniaturized like electronics because the limitations are physical rather than technological in energy. Trying to miniaturize the exploitation of solar flux is like building a mobile Perpetuum or dropping apples upwards: it is physically impossible and it can be shown that it is impossible. See also teacher The convincing analysis of Simon Michaux on this subject.


My first book, The Green Illusion, explains the impossibility of basing today’s society on solar fluxes in detail with quantitative calculations, examples and illustrations. My second book, The Green Opportunity, shows that reducing our energy consumption is much more compelling than replacing solar inventory with increasing solar flux capacity. We can argue about this endlessly, although the facts and figures speak a lot for themselves. It would be very unwise not to seriously consider the scenario that today’s society indeed cannot be sustained without fossil fuels. Current national and international energy policies lack this serious consideration.


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