Industry changes for Half-Hourly metering

Ofgem has recently authorised new regulations for the energy industry which will affect how all suppliers buy, transport and charge for electricity. Known as P272, these changes require certain businesses to switch to Half-Hourly metering.

What changes are happening?

P272 is a modification to be applied to the Balancing and Settlement Code (the code that dictates how suppliers determine power used so that they are able to settle with the supply network). It imposes mandatory Half-Hourly settlement for meter profile classes 5-8, based on real data collected through Automatic Meter Reading (AMR) meters.

How is this different from before?

In the past, most customers have not had meters capable of recording usage on a Half-Hourly basis. As a result, suppliers such as us have had to estimate how much was used every half hour and buy energy based on these estimates. The new AMR meters we’ve been installing for our customers allow us to get real-time readings and to buy only as much power as our customers are actually using on a Half-Hourly basis, and in turn to invoice in the same way.

How do these changes benefit customers?

Ofgem consider that it’s in consumers’ interests to be settled against their Half-Hourly consumption data. AMR meters improve the accuracy and timeliness of the settlement process by allowing access to Half-Hourly consumption data.

Which of my electricity meters will be affected?

Only meters which fall into Profile Class 5-8 will be affected.

Sample MPAN

You can find out which of your meters fall within this category by looking at the Meter Point Administration Number (or Supply Number) on your electricity invoice. If the first (two digit) number on the top line is 05, 06, 07 or 08, you will be affected.

Will my meter need to be replaced?

Most of our customers affected by this change already have a smart meter (also known as an advanced meter) installed which is capable of recording Half-Hourly energy consumption. These customers will not need any change to their metering. If you do not have a smart meter yet, we will contact you to arrange for its installation. You do not need to do anything and there will be no cost to you for this installation if it is needed.

When are these changes happening?

By 1 April 2017, all customers within profile classes 5-8 will need to be settled by Half-Hourly metering. This is a deadline set by Ofgem. To meet this deadline, all energy suppliers began migrating customers to the new metering system on 5 November 2015. This happens either within 45 days of moving to a new supplier or at contract renewal. Any customers with contracts due to expire after the deadline will be migrated mid-contract.

Will there be any extra charges during my current contract term?

Once transferred into the new arrangements, some customers may see additional costs from the electricity distribution company passed through on their invoice. However, most customers will have no additional costs.

We campaigned to Ofgem that these metering changes should only take place at the end of a customer’s contract term, so that if there are any additional costs associated with the change, they won’t affect your current contract prices. Ofgem have agreed to this.

However, they determined that all sites must move to the new arrangements by 1 April 2017, so if your contract term extends beyond this, your meter will be transferred into the new arrangements before your contract ends.

Will my invoice look different?

Yes. Once your metering has moved into the new arrangements you will no longer see a monthly start and end read. This will not affect the amount of energy you consume. You will be able to see all of the Half-Hourly readings for your meter through your Opus Energy online account.

You may also see some additional lines on your invoice which relate to the new charges from the electricity distribution company, such as an Availability Charge, Excess Capacity Charge or Reactive Energy Charge. If you are affected by any of these additional charges, the electricity distribution company for your premises will shortly be writing to you to let you know and to explain what the charges are.

What extra changes might I see on my invoice?

If you have Current Transformer (CT) metering, you will see an Availability (or Capacity) charge appear on your invoice. This is shown in pence per kVA per day and is based on an agreed Maximum Import Capacity (MIC) for your supply. The Distribution Network Operators (DNO) may have already contacted you to explain how the MIC for the meter has been calculated.

If the Maximum Demand exceeds your agreed MIC, an additional Excess Capacity Charge will be incurred. If you are concerned about the level of the MIC, we would advise you contact an electrician for a maximum demand report. If the report shows a different MIC to the one recorded for your supply, you can submit the new MIC to your DNO.

Customers with CT metering may also be charged for Reactive Power. The DNO may levy a charge if more than 5% of the total power consumed is Reactive Power; this is because more current has to be provided to the property to produce the same end power output. The level of Reactive Power is determined by the properties of the specific electrical equipment at the site but most sites consume below the 5% tolerance.

What can I do with the extra Half-Hourly data?

Many customers like to use the Half-Hourly consumption data to assist them with energy efficiency programs. For helpful advice and tips on this topic, please visit

Where can I find more information?

You can find more about this change on Ofgem’s official factsheet.