The UK’s National Electricity Grid connects electricity consumers to electricity suppliers wherever they are. The system for achieving this has both hardware and software components. The hardware consists of the high voltage stations and switching centres. The software monitors demand for electricity and buys just the amount of electricity required from suppliers who offer to sell it. Its a complex system.
The web site used to be dull dull dull – and still is in some ways, but it now has live demand graphs, and graphs showing demand for the last 24 hours or 8 days. It also has downloadable data showing demand every 30 minutes for the last 8 years or so. So you wouldn’t call the site dull now! For example: the figure below shows the data for the last week. Click on the figure to go the National Grid site with updated data. (The left-hand axis is in Megawatts – divide by 1000 for Gigawatts). Notice that peak demand is over 50 GW and consumption is higher right now than it was last week at this time – its probably darker and also colder)
The site tells me that demand at 18:41:45 GMT was 52199 MW. In terms of energy transfers it notes the following energy transfers.
- N.Ireland to Great Britain: -292 MW i.e. the rest of the UK is send electricity to Northern Ireland
- France to Great Britain : -278 MW i.e. we are sending electricity to France at the moment (I am surprised)
- North-South: 10486 MW: Not sure what that means
- Scot – Eng: 460MW : Scotland is suppling 460 MW of electricity to England & Wales.
Looking around the site and seeing the instructions for how companies can bid to supply electricity, makes clear just how complex the system is , and how amazing it is that we are barely aware of its existence.