- made belts have a power drain
- 10 kW drain per yellow belt
- 20 kW drain per red belt
- 40 kW per blue belt
- Make underground belts have a power drain
- 50 kW drain per yellow underground (at each end)
- 100 kW drain per red underground (at each end)
- 200 kW per blue underground (at each end)
- Make splitters have a power drain
- 100 kW drain per yellow splitter
- 200 kW drain per red splitter
- 400 kW per blue splitter
This would be a constant drain whether or not items are being transported.
Plus either:
- belts, splitters, undergrounds do not require power to be connected, just draw from "nearest" power network
or
- allow belts/undergrounds/splitters to transmit power to connected belts (so no power poles required)
On thinking about it… perhaps it would not be terrible to require power poles

The idea of this is to force me to use trains, rather than just running massive belt networks.
In 0.11.22, the lag from more than about 15,000 belts being placed forced me to use trains.
But lag is fixed, and I still want to be forced to use trains

If this has already been done, please point me in the right direction

I'm pretty handy with code, but have absolutely no experience with Factorio modding. If this can be done simply in lua, I'm happy to have a try if someone could point me in the right direction.
Thank you, and
KeepOnBuilding!