User blog:Holomanga/Steven Universe Gems Calc

Calc that I did two years ago; it seems to still stand.

We see Homeworld plan to disassemble/explode the Earth, something that they consider reasonable to take about 5,000 years given that that's the timeframe for the emergence of the Cluster and they're not surprised by it taking an unduly long amount of time. The energy needed to explode a planet is equal to the gravitational binding energy, which for Earth is 2.24 × 1032 J. Over 5,000 years, this is 1.42 × 1021 watts.

Assuming that this would be a similar expense to Pink Diamond as the Saturn V/ISS was to the US, and Pink Diamond commands perhaps A thirtieth note of Homeworld's total power output, this means the gems command around 9 × 1024 watts, corresponding to a type 1.9 civilisation.

(If you think Earth was a more major undertaking for the gems, or Pink Diamond was more important, decrease this number. If you think Earth would have been colonised more quickly, increase this number. The variance is probably about 1.7 - 2.1 depending on assumptions.)

They don't need a lot of power because they have a lot of time to work with; you can build an interstellar empire with a potato battery if you're living for tens or hundreds of thousands of years.