Why do beacons show so much needed power?

[DarkShadow44]

Beacons that are not fully powered show as needing 2.4 MW on the electrical network overview. Why is this?

Screenshot 2021-07-07 122123.png (1.68 MiB) Viewed 1163 times

[boskid]

This reported power need is based on the electric energy buffer of a beacon which holds 5.07 x maximum energy consumption (excluding drain). With that much power the beacon would be fully charged within a single game tick. When a beacon is powered and its fully charged, this value will reduce to the actual power usage.

[DarkShadow44]

Ah, I understand. That's a bit unintuitive though, I'd expect it to show what amount of power is needed for continuous operation. When looking only at the graph, I'd build a 2.4MW power plant and then wonder why it's not fully used. Do you know why it is like that?

Btw, do other entities also all include their internal buffer for their satisfaction calculation?

[boskid]

Its to keep the implementation sane. For machines which power usage changes with time (inserters etc) the amount of energy used by machine is directly proportional to the amount of energy missing in the energy buffer at the end of given tick so it can be used to compute the current power requirement. Trying to work around this would cause this value to lie as the beacon is capable of consuming 2.4MW but it only happens for a single tick and in general it would require to scan the entire electric network only to cap energy requirement of every machine's electric energy source by the max power consumption. For me this is an acceptable tradeoff (not doing it that way) which also does not introduce extra weird cases.

Beacon is kind of exception compared to other entities as its energy buffer is 5.07x max power consumption each tick. Combinator and programmable speakers are 2.07x max power consumption, everything else is basically 1.07x their max power consumption.

[DarkShadow44]

I see, thanks for the explanation!