"According to the United Nations’ Food and Agriculture Organization, the global average caloric intake is 2,800 kcal per day, translating to an average continuous power of about 135 W. The mineral requirements to accomplish this constitute just over 3% of body mass, or 2 kg for the global average body mass of 62 kg. Thus, a human achieves roughly 70 W per kilogram of minerals. Note that even though the human body is only 20–25% efficient at converting metabolic energy into external mechanical work, the rest is not waste to us: it provides crucial thermal energy to keep body temperature up, and thus counts as a critical contribution. Let’s look at solar panels. Typical 60-cell panels produce 300 W in full sun, and have a mass around 20 kg. Straight away we compute 15 W/kg—a factor of five lower than human performance. But to be fair, we must account for the fact that the sun is not always directly in front of the panel, producing a typical capacity factor of 20%, or an average power delivery of 60 W. Now the deployed panel delivers 3 W/kg: less than 5% as “efficient” as a human, in mineral terms. Massive wind turbines at 20% capacity factor (typical global average) score even worse, at 0.4–0.6 W/kg. Without the mass-dominant concrete pad, a wind turbine would pump out 1.6–2.4 W/kg, for the short time it remained standing. Just as a wind turbine needs a mounting base, a realistic utility-scale solar deployment has a material mass far in excess of the bare panels: support structures, interconnect wiring, inverters, storage (if truly replacing fossil fuels). I would not be surprised if a whole-system figure dropped to 1 or 2 W/kg, while humans stay smugly perched at 70. The score for wind would erode as well once other necessary components are considered—especially storage. Moreover, the minerals needed by humans are in wide circulation within the community of life at the surface: no mining (and associated tailings, energy, processing, pollution) necessary. Thus, biology has far exceeded technology in capturing the inexhaustible flow from the sun using a minimum of minerals—and those being extracted from and re-deposited to the soil in a continuous, self-sustaining cycle, importantly. Biology and evolution really figured things out! Modernity looks like a bumbling idiot by comparison—like R2D2 in a stair-climbing competition against an athlete."