Ask your electricity supplier for the half-hourly consumption data for each of your meters, covering at least the last 12 months, as a spreadsheet. Many suppliers also let you download it from your online account.
Who has it
If your meter records half-hourly readings, your supplier receives them and can send them to you. Larger business sites have had half-hourly meters for years, and more meters are moving to half-hourly settlement, so it's worth asking even for smaller premises.
You may also find it in:
- Your supplier's online account, often under "consumption", "usage" or "data download"
- Your energy broker or energy manager, if you have one
- A building management or energy monitoring system that can export meter data
- A smart meter app or service that offers half-hourly downloads
What to ask for
A request like this works:
Please send the half-hourly consumption data (kWh) for meter [MPAN], from [date] to [date], as an Excel or CSV file with one row per day and 48 half-hourly columns.
- One file per meter. Name each file after the site, because the analyser uses the file name as the site name.
- At least 12 months of data, so annual figures and seasonal patterns are reliable. Up to three years helps show longer-term trends.
- Readings in kWh for each half hour are best. Files in kW also work, and the analyser tells you which it found.
Your meter's MPAN (the 13-digit number on the bottom line of the supply number) is on your electricity bill. How to read it.
Download a letter template (Word). It lists what to ask for, with spaces for your MPANs and dates.
Your right to the data
Since 1 December 2022, business customers with a smart or advanced (AMR) meter, and anyone they nominate, can ask their supplier for up to 12 months of their historic smart meter data, free of charge and in a machine-readable format. The supplier must reply within 10 working days.1
Supplier by supplier
Where to find half-hourly data with some of the larger business suppliers, from their own published guidance:
File formats the analyser reads
| Layout | Looks like |
|---|---|
| Day per row | Date, then 48 columns of half-hourly readings |
| Day per column | Dates across the top, 48 rows of readings |
| Timestamped | One row per reading, with its date and time |
Excel (.xlsx, .xls) and CSV files both work. Extra columns, such as meter references, are ignored. If a file can't be read, the analyser explains why.
Once you have the file, our guides explain what to look for. Not sure what your file should look like? Download our example file and compare.
If your supplier can't provide it
If your supplier says the meter doesn't record half-hourly readings, ask whether it can be replaced with a smart or advanced meter that does. In the meantime, check whether a building management or monitoring system on site keeps its own records. Monthly meter readings will show how use changes through the year, but they can't show the daily and overnight patterns this analyser looks for.
Questions people ask
What is half-hourly electricity data?
A record of the electricity used in each half hour of the day. That's 48 readings a day and 17,520 in a normal year. It shows when a site uses electricity as well as how much.
How far back can I get data?
Ask for at least 12 months, and up to three years if your supplier has it. A full year shows seasonal patterns and means annual figures are measured rather than estimated.
Does it cost anything to get my data?
Ask your supplier. Many provide it free on request or through your online account.
Where do I find my MPAN?
On your electricity bill. It is the 13-digit supply number, usually in a box labelled S or "Supply number".
