ok, as you PMed me about this some time ago, I'm feeling free here to specify what it is about^^:
what andreasaspenberg wants is to recreate the 'Command and Conquer' Power system. As i never played Cnc i had to look for vids or explanations what it is about. What i got was this (plz correct me if I'm wrong): Energy is a additional resource produced in 'Power Plats' ('PP') (I'm assuming periodically), if a PP is build close to 'Blue Crystals' its power production is somehow increased. Also you can build 'accumulators' next to your PP to further increase the power output.
For this part, i would suggest a periodic trigger that loops through the payers counting the powerplants, then which of those are close to blue crystals and which have accumulators close to them and then calculating the total power gain.
Additionally andreasaspenberg wants to have a power bar to visualise your current amount of power (what means that there is a maximum power capacity(?)). He wants it to be located above the minimap (what IMO is a bad idea, not only hard to make i think but also, unless power is the only recource, why don't just make a multiboard-bar so all resources are in one part of the screen?).