Explainer
A half hourly meter records electricity use in every 30 minute period. Until now only larger business sites were settled that way. Under market wide half hourly settlement, every meter point in Great Britain will be. Here is what that means.
By Christopher Fagan, Managing Partner, PEF Consulting Partners
A half hourly meter, often called an HH meter, records how much electricity is used in each of the 48 half hour periods of the day, and that data is used for billing and settlement. A traditional meter only records a running total that is read from time to time, so the usage in between has to be estimated using standard profiles.
For years half hourly settlement was mandatory only for the largest sites, those with a maximum demand above 100kW. In 2017 the industry change known as P272 moved business sites in profile classes 5 to 8 onto half hourly settlement as well. Smart meters can record half hourly data too, and many homes and small businesses with smart meters already have it, even though most have been settled on profiles until now.
You can tell how a supply has been settled from the first two digits of the MPAN on the bill, the profile class. Profile class 00 means half hourly; 01 to 08 mean the supply has been settled on a profile. Our guide to what an MPAN is explains the rest of the number.
Market wide half hourly settlement, or MHHS, puts every meter point in Great Britain on half hourly settlement. Smart and advanced meters provide actual half hourly readings; where a meter cannot, half hourly values are estimated from load shapes built from real half hourly data. Every meter point must be migrated by 7 May 2027.
Wholesale electricity is traded and settled in half hour periods, so prices move through the day: usually highest at the early evening peak and lowest overnight and, on sunny or windy days, in the middle of the day. With half hourly data on every meter, suppliers can offer tariffs that pass those differences on, such as time of use tariffs that reward moving consumption away from the peak.
Many business sites settled half hourly use AMR meters, which send readings automatically over a mobile connection. Smart meters do the same through the national DCC network. Our comparison of AMR and smart meters sets out the differences.
A meter that records electricity use in each 30 minute period, so the supply can be billed and settled on actual usage rather than estimated profiles.
Check the MPAN on your bill. A profile class of 00 at the start of the top line means the supply is settled half hourly.
No separate meter is needed. MHHS settles every meter point half hourly, using smart and advanced meter data where it exists and load shapes where it does not.
HH is short for half hourly. An HH meter records consumption every half hour.
Related reading: what is MHHS?, electricity demand forecasting, what is ECOES?, smart metering and DCC delivery, smart meters in Ireland.
If your metering, data or settlement processes are not ready for every meter point to settle half hourly, we can help you find the gaps before they cost money.