Originally Posted by Burgundymog
Back in the 70's I had a friend that worked in the national grid control room, his job was switching supply around when demand outstripped demand.


Yes, it's always been done like this as there's not been really any practical way to store excess electricity on a minute-to-minute basis. When demand exceeds supply the load causes the generators to slow down, dropping the frequency and causing brown-outs, and when the supply exceeds demand the generators spin up and frequency (& voltage) increases.

For unexpected demand there's the pump storage schemes like Dinorwic that can ramp up within a few seconds, and gas-powered generators can be on-line in a minute or so. Of course, now with the increasing use of battery storage, the focus will switch more towards that

Fortunately these days there are loads of automated ways to help out with demand response, like getting supermarkets to turn off their freezers for a few minutes. Some of the bigger process factories than can stop their machines at short notice are able to benefit from extremely favourable supply contracts - they get their 'leccy extremely cheap.


Tim H.
1986 4/4 VVTi Sport, 2002 LR Defender, 2022 Mini Cooper SE