Electricity - Real Time Operational data

Frequency

The normal system frequency is 50Hz. As electricity cannot be stored, the instantaneous generation must match the demand being taken from the system. If the instantaneous demand is higher than the generation, the system frequency will fall. Conversely, if the instantaneous generation is higher than the demand, the frequency will rise. System frequency will therefore vary around the 50 Hz target and National Grid has statutory obligations to maintain the frequency within +/- 0.5Hz around this level. However, National Grid normally operates within more stringent 'operational limits' which are set at +/- 0.2Hz.

Electricity Demand

This is the total instantaneous MW demand being supplied across England, Wales and Scotland. It is the sum of the output of all the generation connected to the GB Transmission System plus imports from External Interconnectors i.e. from France-GB and Ireland-GB (Exports to France and Ireland are subtracted). The generation from pump storage is treated in the same way as other directly connected generation and hence is included in the instantaneous demand calculation. The pump storage demand or the station transformer demand are not netted off (i.e. they are not subtracted from the total instantaneous demand).

Data Source

The graphs shown here are based on information supplied from www.bmreports.com.

Demand

Real Time Demand Data - Last 60 Minutes
Electricity demand - Last 24 Hours
Electricity demand - Last 7 Days

Frequency

Real Time Frequency Data - Last 60 Minutes
 

Many of the files available to download on this page are Acrobat PDF files. To access these you will need Acrobat Reader which is available from the Adobe web site.