In Scotland one issue is that the UK electricity market is national (unlike in eg norway). So even if local supply is very high and interconnects are not large enough to export to england - we must pay the higher national rate. As octopus ceo suggested if the UK energy market has regional pricing then electricity in scotland would often be a lot cheaper and in some cases industrial demand would move there. But that would disadvantage the SE of England so will never happen.

Conversely, standing charges ARE regionalised - because that does advantage the SE of England. Oh well!