#123 - Kardashev Type II Civilisation

This very intriguing statement from the SpaceX Prospectus made me dig into the details. What I found is not only a question of feasibility, but a deeper question about our civilisation’s attachment to growth, scale, and abundance.

Nikolai Kardashev was a Soviet astrophysicist who proposed a scale to classify a civilization's technological development based on its energy consumption. The scale proposes three levels of civilisation. Type I is a planetary civilization, which can harness all forms of energy that can be reached on the host planet, such as fossil fuels, solar, and geothermal power. Types II and III, known as stellar and galactic civilizations, respectively, are capable of extracting and utilizing all energy created by their respective systems [2].

So far, so good. It sounds reasonable until we check the actual numbers. In 2025, humanity consumed 592 EJ of energy, or ~18.8 TW.

The Earth intercepts roughly 174,000 TW of solar power, which means that today we are consuming just 0.0108% of the energy required to reach Level I on this scale.

The Sun’s total energy output is 383 trillion TW, so humanity uses about 0.0000000000049% of the Sun’s total output.

These numbers are so disproportionate that they stop sounding like engineering targets and start sounding like mythology. In fact, both levels seem, in reality, more like fantasy than real life, and yet this became a statement of a serious company valued today at $2.011T. Is this ambition, or ambition inflated into mythology? I think the latter, even though the achievements of SpaceX are undeniable.

But this is not a reflection on this company’s valuation. I am thinking instead about the broader challenge of a volume obsessed economy. We seem to be so stuck in the notion that "more is always better" that every sign of something additional triggers excitement.

Reaching a Level I civilisation means we would have to increase energy use 9,300 times. If we keep the growth level at 1.5% per year, which is similar to the growth since 1800, we would need over 600 years to get there. For Level II, it is over 2,000 years.

Current energy consumption translates to 2.3 kW/person, which is akin to 23 energy slaves per human on Earth [5]. Energy consumption has grown from an estimated 0.65 TW in 1800 [6], almost a 30-fold increase. Per capita, however, the increase is smaller — about 3.5 times. An average person in 1800 already had about 6.5 energy slaves.

Approaching Level I civilisation energy use would increase this to 213,000, if we assume a stable population. This may be a very optimistic assumption, given global demographic trends.

My concern is that we already struggle to use wisely and efficiently the 23 energy slaves we already have. There are two main broader considerations related to this.

Efficiency

Energy efficiency means using less energy to provide the same or a better service.

The world's energy system is only about 40% efficient, meaning that almost 60% of energy inputs are wasted. The U.S. energy system is even less efficient, wasting almost 70% of energy inputs [7]. In other words, our energy slaves provide useful work only 30–40% of the time.

A chart that compares industrial pumping efficiency, measured as power required to pump 1 gallon of water per minute, with the human body illustrates this nicely. The human body is 15 times more efficient per watt of energy compared to a standard installation, and still almost 5 times more efficient than a low-friction, modern pumping system.

Delivered Work

Delivered work is about the gallons of water per minute we need. You may remember an earlier post about Jevons Paradox [8], which dives into demand growth alongside all the efficiency measures humanity takes. The key question here is what we do with additional efficiency or an additional energy slave. What is the sense of moving two tons of car to transport an 80 kg human? How does additional weight or power of this car translate into an improved human experience? What do we need to develop further, and what is the ultimate objective of development?

I do not have good answers. But perhaps the real problem with the SpaceX statement is not only feasibility. It is the civilisational dilemma beneath it: whether progress means commanding ever more energy, or we can progress without constant growth of the resources we use.

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References and Notes

1. Space Exploration Technologies Corp. FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

2. Zhang, A., Yang, J., Luo, Y., & Fan, S. (2022). 2060: Civilization, energy, and progression of mankind on the kardashev scale. arXiv preprint

3. Energy Institute. (2025). Statistical review of world energy 2025 (74th ed.). Energy Institute. https://www.energyinst.org/statistical-review/resources-and-data-downloads

4. Harrop, B. L., & Schulze-Makuch, D. (2010). The Solar Wind Power Satellite as an alternative to a traditional Dyson Sphere and its implications for remote detection. International Journal of Astrobiology, 9(2), 89-99.

5. If one “energy slave” is defined as a human delivering about 100W then 2,300W÷100W=23

6. https://ourworldindata.org/energy-production-consumption

7. https://understand-energy.stanford.edu/energy-resources/renewable-energy/energy-efficiency

8. https://www.resilienceinstitute.info/post/112-efficiency-and-expansion