TL;DR
Add graph to show potential power production in power tab.What ?
Add toggle-able graph on power tab, showing potential power for every power source connected to network.Why ?
Sometimes to check how much power this solar plant produce we must do math. If numbers are generalized to 1000, problem only arise. For example 100 solar panels can produce 6 MW of additional power. Is not meaning value in total, if we use cold steam, 100 of steam engines can produce 90 MW. Same situation is for accumulators.Potential power production can be useful to check what power source is "main" in out electricity network and give info what source have insufficient fuel or producing limit.
This idea cannot be introduced by mods, so only way to see these graph is only ad in game. Is not create mess in power tab, due in Factorio vanilla we have only 4 power sources, so adding next 4 "dummy" graph does not change anything in GUI but give information that only showed on gauge in the middle.