How do you request interval data for a business solar assessment?

Request half-hourly electricity consumption from your supplier, identifying your supply, date range and authorised recipient. Government guidance says non-domestic customers and nominated third parties can request free access to up to 12 months of smart or advanced meter history [S1]. Specify units, timezone and reading quality so the file can support a solar assessment. Checked October 2026.

Last checked 18 October 2026

How do you get half-hourly electricity data for solar?

Start with your supplier’s business portal or customer-service team. Ask for the underlying interval file rather than a screenshot of the usage chart. The on-request offer covers smart and advanced meters; it does not mean every old meter has recorded a usable history [S1]. These Ofgem-regulated supply rules concern Great Britain. For a Northern Ireland site, confirm the applicable arrangements with your supplier.

Build your request around the supply that the proposed solar array would serve. Ofgem defines the Meter Point Administration Number (MPAN) as the identifier for your electricity supply [S3]. Ask your accounts team to check it against the bill before sending the request. Do not substitute the account number or a photograph of the meter.

Use this guide alongside solar panels for business and half-hourly metering. The aim is a traceable assessment file, with its limitations visible before anyone sizes equipment.

What should your interval-data request say?

Copy the draft below into your own message. Replace every placeholder and check the recipient before sending. This is a practical request template, not an official form or legal advice. Check any disputed contractual authority with your solicitor.

Subject: Electricity interval-data request for a solar assessment

I am [name and role], authorised to act for [electricity account holder].

Site address: [address and postcode]. Supplier account: [reference]. Import MPAN: [supply identifier]. Meter serial number: [if known]. Export MPAN, if relevant: [identifier or not applicable].

Please provide the available half-hourly electricity import data from [start date and time] to [end date and time]. Confirm whether the final boundary is included or excluded.

Please provide a machine-readable file, preferably CSV, with timestamps, interval lengths, energy units and actual/estimated/missing-reading flags. Keep import and export separate.

State the timezone, treatment of daylight-saving changes and whether timestamps mark interval starts or ends. If you use settlement-period numbers, include the date and an explanation of the mapping.

Please identify gaps, meter changes and any periods for which no data is held.

Send the file to [account holder’s approved address]. Alternatively, my nominated recipient is [organisation and contact], authorised solely to receive the specified records for this solar assessment. Authority expires on [date]. Confirm any additional verification needed.

Please acknowledge the request and explain any unavailable records or proposed additional charges before proceeding.

Request a complete seasonal cycle where available. That is an assessment recommendation, not a promise that missing history can be recovered. Save the request, acknowledgement and original download together in your private project records. Keep these account details out of public enquiry text.

Is access free, and when should your supplier respond?

Current government guidance describes free access to up to 12 months of historical smart or advanced meter use. It says suppliers must respond within 10 working days. It also permits nomination of a third party [S1]. Keep the distinction between a response and successful delivery of every requested field.

An older Ofgem decision discussed timely access when larger sites moved to half-hourly settlement [S2]. Do not use that historic letter alone as the present-day service deadline. Point to the current data offer, ask which obligation applies to your meter, and retain the supplier’s written explanation if access is refused.

For a partial response, reply with a precise list: missing supplies, date gaps, unreadable units or absent authority confirmation. Ask whether the records exist and what is needed to release them. Avoid accepting a monthly summary without recording that the requested detail remains outstanding.

What file layout and timezone should you ask for?

Our recommended assessment layout is a row for each interval, with an unambiguous supply identifier. A different layout can work if your assessor documents how it is read. Agree these fields before transforming the file:

Check clock-change treatment with the data sender rather than deleting repeated-looking timestamps. Also check the generation model’s convention. The PVGIS daily-profile tool can show UTC or local standard time, but does not apply daylight-saving time [S4]. UTC means Coordinated Universal Time. Ask your assessor to document the alignment before matching generation to demand.

How do you check the data before sizing solar?

Keep an untouched original and work on a copy. Compare the requested dates with the delivered range. List blank cells, repeated rows and unexplained changes in units. Ask for clarification instead of silently replacing missing readings with zero. Reconcile interval totals against bills covering the same boundaries.

Add a short operating diary: shutdowns, changed opening hours, new equipment and planned vehicle charging. Ask the assessor to separate the measured history from assumptions about future operation. If solar already exists, provide its generation records too; ask what the import meter captures before treating it as total demand.

Read load profiles, commercial solar sizing and solar self-consumption. For price context, use business electricity data; apply your actual contract inputs in any assessment.

What should you do next?

Start with the cut energy costs hub and site check. Once your data pack is ready, get matched with an installer that covers your area.

Piggy Pineapple Ltd operates this referral service. We refer enquiries to installer partners and may be paid a fee. Our owner holds shares in at least one partner. Before sharing your details, we name the partner and disclose any shareholding our owner holds in it.