Umbrella is a energy beam defense facility, that can protect against Coronal Mass Ejection (CME) and space-based energy beam weapons. Only 1 is needed per surface against CME.
1) The Umbrella has passive power draw of 10MW and an internal battery of 1GJ.
2) Base power draw for CME on a either planet/moon with 5000 radius and 100% solar is 160GJ over 2 minutes with peak draw of 2GW at 1 minute mark.
3) The power draw increases or decreases if the radius is larger/smaller. It is also directly proportional to solar strength.
4) If Umbrella fail to satisfy power demand the CME will not be defended, as result player may experience damage.
5) For orbits and belts power draw is similar as if it was a 5000 radius, but 20% of the solar value of that orbit surface (estimate).
Calculating Umbrella power draw on Nauvis for CME:
By default Nauvis is 5692 radius, thus:
5692 / 5000 = 1.1384
Using this modifier we can calculate power draws (100% = solar modifier):
1.1384 x 2GW x 100% = 2.28GW
1.1384 x 160GJ x 100% = 182GJ
Players only have to provide either 2.28GW of sustained power or 182GJ excess power in form of energy storage (steam batteries, accumulators) over 2mins. However, a combination of the two also works.