On Friday 21st April, the [UK National Grid announced the following on twitter](https://twitter.com/NGControlRoom/status/855544665172529156):

> 
> National Grid can confirm that for the past 24 hours, it has supplied GB's electricity demand without the need for #coal generation.
> 
> 
> [!["no coal generation for 24 hours"](https://i.stack.imgur.com/F67XI.jpg)](https://i.stack.imgur.com/F67XI.jpg)
> 
> 
> 

They further clarified [in a following tweet](https://twitter.com/NGControlRoom/status/855550360852852736):

> 
> Today's average generation mix so far has been gas 50.3%, nuclear 21.2%, wind 12.2%, imports 8.3%, biomass 6.7%, solar 3.6%
> 
> 
> 

When I speak to people living here in the UK or abroad about this, they bring up that it is unclear whether:

* coal stations were totally shut down for that 24 hour period (and other 6–8 hour periods earlier that week) and thus not burning coal or generating pollution, or
* coal stations were running, burning coal, and generating power (which was either consumed elsewhere or entirely wasted) but Great Britain was powered without coal generation for the period.

I agree with them that it's ambiguous. A common point of doubt has been that surely they can't just shut down and start up the coal plants that fast.

Someone in the twitter thread [requested some clarity around this](https://twitter.com/InspectorsClews/status/855681835363426304), to which National Grid did not reply: “Were there plants burning coal, but they weren't feeding the grid? Or were they all totally cold?”

**Were coal power stations running and generating power that Great Britain didn't use, or were they actually shut down?**