Most UK businesses treat their energy contract renewal as an admin task rather than a commercial decision. That is a costly habit. If your site has a half-hourly electricity meter — or you have access to interval consumption data — you are sitting on one of the most powerful negotiating tools available before you sign your next tariff. This guide explains what half hourly energy data is, how to obtain and read it, and precisely how to use it to inform smarter procurement choices at renewal.
What Half-Hourly Energy Data Actually Means
A half-hourly (HH) meter records how much electricity your site draws from the grid in every 30-minute settlement period throughout the day. Unlike a standard meter that simply accumulates a total, HH meters transmit data automatically to your supplier and to the national grid's settlement system.
This creates a detailed consumption profile — typically expressed in kilowatt-hours (kWh) per half-hour — that shows not just how much energy you use, but when you use it and how that changes across days, weeks, and seasons.
For procurement purposes, this matters because electricity is not priced as a flat commodity. Wholesale costs, network charges, and balancing charges all vary by time of day and season. A business that consumes heavily during peak evening periods carries a different cost risk than one that runs most of its load overnight.
Who Has a Half-Hourly Meter?
Sites with a maximum demand (MD) above 100 kW are mandated to operate under Profile Class 00 — the HH settlement class — by Elexon, the body that runs the UK's electricity balancing and settlement arrangements. Many sites below that threshold have been voluntarily moved onto HH metering as smart meter rollout continues, particularly those with advanced meters installed under the SMETS2 programme.
If you are unsure whether your site is HH-settled, check your electricity supply contract or ask your current supplier for your Meter Point Administration Number (MPAN) profile class. The second digit of the top line of your MPAN indicates your profile class; 00 denotes HH settlement.
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How to Obtain Your Half-Hourly Consumption Data
Before you can use your data, you need to get hold of it in a usable format. You have several routes.
From your current supplier. Your supplier holds your HH consumption data and is obliged to provide it on request. Ask specifically for your interval data in CSV or Excel format, covering at least the past 12 months. Many suppliers offer this through an online portal; others will email a file on request.
From your data collector or data aggregator. Under the HH settlement framework, an accredited Data Collector (DC) gathers your metering data. You can request this directly, particularly if you are changing supplier and want independent access.
Via a bureau or energy consultant. Many commercial energy brokers and consultants can pull your HH data on your behalf, often presenting it in a formatted dashboard. If you use a broker to compare business electricity and gas contracts, confirm they will share the underlying data with you, not just an interpretation.
Through your own metering equipment. If your site has a Building Management System (BMS) or sub-metering, you may already have interval data available internally, though aligning it with settlement-quality data is advisable before using it for procurement negotiations.
Once you have the data, open it in a spreadsheet. Each row will typically represent one 30-minute period, with a date, time, and kWh consumption figure.
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Reading the Data: What Patterns to Look For
Raw interval data can look overwhelming — a full year produces over 17,500 data rows per meter. The goal is not to read every line but to identify patterns that have commercial significance.
Demand Profile Shape
Plot your average weekday consumption across 48 half-hourly periods. This gives you a demand curve. Common shapes include:
- Flat profile: Consistent consumption around the clock — typical of cold storage, data centres, or continuous manufacturing.
- Single peak: A sharp rise in the morning and fall in the evening — common in offices and retail.
- Double peak: Morning and afternoon peaks with a midday dip — found in hospitality venues with lunch and dinner service.
- Irregular profile: Unpredictable or lumpy consumption — sometimes indicates equipment inefficiency or unscheduled overnight loads.
Your demand shape directly affects how suppliers assess your contract risk and which tariff structures suit you best.
Maximum Demand
Identify the single highest 30-minute consumption reading across your dataset. This is your peak maximum demand, usually expressed in kVA or kW. Network charges — specifically the Triads system for transmission and Distribution Use of System (DUoS) charges for certain band periods — can be significantly influenced by when and how hard you hit peak demand.
Seasonal Variation
Compare consumption months side by side. Note whether your highest demand falls in winter (heating, lighting) or summer (cooling). Suppliers factor seasonal risk into fixed-rate contracts; if your data shows relatively flat seasonal variation, you may be able to negotiate a tighter risk premium.
Overnight and Weekend Waste
Look at consumption between midnight and 06:00, and across weekends when your business is closed or quieter. Unexplained baseline consumption during these periods often points to equipment left on standby, inefficient HVAC scheduling, or old refrigeration units cycling continuously. Reducing this before renewal lowers your forecast volume and therefore your contract cost.
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Looking to reduce your business operating expenses? Aarubi can review your energy, card processing, insurance and business funding options. Request a free consultation
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Using the Data to Inform Your Procurement Decision
Understanding your data is preparation. Using it is the commercial step.
Choosing the Right Contract Structure
The table below summarises the three main commercial electricity contract structures available to UK SMEs and how your HH data should influence which you consider.
| Contract Type | How It Works | When HH Data Helps Most |
|---|---|---|
| Fixed rate | Unit rate and standing charge locked for contract term | Confirm your volume profile is stable; a fixed rate on volatile consumption can mean paying for unused capacity or facing reconciliation charges |
| Flexible / basket | Tranches of wholesale energy purchased at intervals through the term | HH data lets you assess whether your load is stable enough to hedge in forward markets; suitable for larger or more sophisticated buyers |
| Pass-through / transparent | Third-party network and levy costs passed on at actual rates; supplier margin fixed | Your HH profile directly affects the network charges passed through; a flatter profile usually benefits from this structure |
For most SMEs, a fixed contract is the most practical choice — but your HH data should validate that decision rather than leave it to default. If your data shows highly variable demand, a fully fixed rate may price in a risk buffer that you end up paying for even if the volatile periods never materialise.
Setting a Realistic Consumption Forecast
Suppliers quote against a forecast annual quantity (AQC). If your HH data shows that your business has grown, downsized, or changed its operational hours in the past 12 months, historical billing estimates may be inaccurate. Providing a supplier with accurate volume and profile data can prevent both over-procurement (where you pay for energy you do not use) and under-procurement (where you face expensive top-up purchasing on the spot market).
Timing Your Renewal Window
The 12 months of HH data you request should ideally include your most recent winter peak. If you are renewing in autumn 2026 — a common contract start window — you want data that captures at least one full winter cycle. This prevents suppliers from pricing in an assumed worst-case peak that your actual profile does not support.
Most fixed commercial energy contracts run for 12, 24, or 36 months. Your renewal window typically opens 6–12 months before your current contract end date. Use that window to pull and analyse your HH data before approaching the market, not after you have received quotes.
Compare business energy tariffs at Aarubi to see what fixed and pass-through options are available for your site profile.
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Common Mistakes SMEs Make With Consumption Data
Even businesses that obtain their HH data often fail to use it effectively. These are the most common errors.
Using only billing data. Invoice consumption figures are rounded, estimated, or averaged. They mask the spiky demand events that drive up network charges. HH data at settlement quality is more reliable for procurement analysis.
Ignoring Triad risk. Triad periods are the three half-hours of highest national demand between November and February. If your business operates during those periods — typically weekday evenings between 17:00 and 19:30 — your Triad exposure will be baked into supplier pricing. HH data can help you identify whether load-shifting during those windows is feasible.
Renewing on a like-for-like basis without review. If your operational hours or equipment have changed, your old contract structure may no longer fit your profile. Renewing on the same terms is not neutral — it may mean paying for a risk profile that no longer reflects your business.
Not sharing data with the broker or supplier. Some businesses accept quotes without providing profile data, leaving suppliers to use an estimated profile. Providing actual HH data gives suppliers less reason to price in uncertainty.
Overlooking reactive power charges. If your HH data is accompanied by reactive energy readings (kVArh), and your power factor is poor, you may be incurring additional charges. Correcting power factor before renewal can reduce network costs independently of the tariff negotiation.
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What to Do in the 60 Days Before Your Contract Ends
A focused pre-renewal review using HH data does not need to be complex. This is a practical sequence for most SME sites.
Work through the following in order:
- Request 12–24 months of HH interval data from your supplier or data collector in CSV format.
- Identify your peak demand, your overnight baseline, and your seasonal variation.
- Note any operational changes since the last contract was signed — new equipment, extended hours, remote working patterns, or site changes.
- Benchmark your current contracted unit rate against published indicative rates for similar profile classes; your business energy adviser or broker should be able to assist.
- Decide whether a fixed, flexible, or pass-through structure best fits your consumption shape.
- Brief any broker or comparison service with your actual HH profile data, not just your MPAN and billing address.
- Check whether load-shifting or efficiency measures before the new contract starts could reduce your forecast volume or lower your Triad exposure.
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Action Checklist
- Confirm your MPAN profile class and whether your site is HH-settled.
- Request 12–24 months of interval consumption data from your supplier, in CSV or Excel format.
- Plot your average daily demand curve across 48 half-hourly periods.
- Identify your maximum demand event and check whether it falls in a Triad-risk window.
- Review overnight and weekend baseline consumption for reduction opportunities.
- Confirm your forecast annual consumption volume before approaching suppliers.
- Decide on the contract structure — fixed, flexible, or pass-through — based on your profile shape.
- Provide your HH data file to any broker or comparison service before quotes are sought.
- Set a renewal reminder 9–12 months before your current contract end date.
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