When placing the floating electric pole from Cargo Ships, Inbuilt Lighting will crash, since the floating pole has a supply area of 0 and there's no "hiddenlight-0" entity. I suggest that Inbuilt Lighting defaults to either 1 or 2 if this happens.

Had a look and a play with this and for the short term I have fixed the error and the 0 supply area power poles are unlit.

I have tried different lit areas for this specific example.
https://gfycat.com/GoldenLegitimateBumblebee
I am leaning towards as a minimum always lighting up an area that covers the entities image (drawing_box). So in this example that would be a lit area of 3. As I think just lighting up the base of the pole feels odd.
This would mean that for power poles with 0 to 2-3 supply area, small imaged sized power poles would light up a smaller area than large image sized power poles.