How to calculate the annual energy consumption of robots

You probably have to ask the manufacturer. It will depend very much on what the robot's duty cycle is, how much payload it is carrying, how many holidays there are....

there is no good or simple way to calculate... same robot could be working on something slow, few hours a week, OR it could be fast pace press transfer. speed (acceleration) makes huge difference. optimization of program and fluidity of motions also makes difference. payload and supplementary load make a difference. programmed paths make a difference....

for example consider same program, same robot, same payload, same path and just running at 50% speed instead of 100% speed makes current draw or power consumption go down by about 70%. It is a square relationship so theoretically it would be 75% (1/4) but there is some overhead....

Next there are external axes etc.

rough estimate is to see how the controller is powered and what the bottle neck is. in case of NA version of controllers one can relate that limit to included transformer (8kVA or for largest units 13kVA).

assuming utilization based on process and number of working hours per year, one can get that estimate. real value would be to actually run robot and measure consumption. As mentioned this would be different for each robot that is used differently (even if the robot is the same).

someone running robot around the clock for say 7000h a year where utilization is 60% and rated power is 8kVA would end up at some 33600kWh. but if programmed speeds are only 75% then that number would be 18900kWh. similarly one would need to assume other variations (load, etc.)

As SkyeFire and panic mode have eluded to, this is not a simple question, although the person asking you may think differently😉

Fanuc has a pretty display screen under the status menu that shows power consumption. I think they added it right around the same time they began offering their power regen option...

I haven't looked into it, but it may offer a power consumption meter. At the least, there's got to be a system variable associated with it that could be tracked.

Maybe non-yellow robots offer a similar feature.

KUKA does offer energy monitoring on KRC4, but I have never looked into it or used it. My guess was that question was asked since robot is considered for purchase and not yet available. If one has the robot and it is running some program, one can easily hang a clamp meter on one (or all) phases and see current draw - power is easily computed from that even if device does not offer own means to monitor power or energy... On KRC one should also be able to do that just by using Trace tool that is part of the KSS