Half-hourly electricity data can show when a business is using energy overnight, at weekends or during holidays. Compare those patterns with how the premises actually operate, then investigate unexplained consumption with the site team. Background use is not automatically waste: refrigeration, security, servers and protection systems may need to remain running. This guide concerns business premises in Great Britain.
Start with the right supply and a useful dataset
Identify the electricity meter point administration number (MPAN) and physical meter before analysing a file. At a shared site, check which units and equipment the supply serves. Our identifier guide helps distinguish supply, meter and account references.
Ask the supplier or relevant data provider how to obtain interval consumption information and what authority is needed. Confirm the period available, units, time convention and any missing or estimated intervals. Do not interpret a blank record as zero consumption without clarification.
Choose a period covering normal weekdays and weekends, adding holiday or seasonal periods where useful. Note temporary closures, equipment changes and unusual events. A single exceptional week can suggest questions, but it is a weak basis for conclusions about the whole year.
Compare the graph with the operating timetable
Write down actual staffed hours, cleaning times, production shifts and timed equipment operation. Include early starts, late deliveries and occasional weekend work rather than relying only on the opening hours displayed on the door.
The Carbon Trust's better-business guide illustrates using bills and meter data to investigate energy use, including half-hourly profiles. This older guide is useful here for general monitoring principles; its profile-class and tariff advice should not be treated as current guidance. The practical value is locating a pattern that monthly totals can hide.
Look for the level before opening, the change when activity starts, the fall after closing and differences between occupied and unoccupied days. Compare similar operating periods before deciding something has changed. Weather, production and occupancy can all help explain a different pattern.
Keep energy consumption separate from capacity. A half-hour's kWh value is energy over that interval; it is not the same figure as the agreed supply capacity in kVA.
Find out what must stay on
Discuss the pattern with people who know the building and equipment. Use this checklist to organise a safe investigation:
| Possible load | What to establish |
|---|---|
| Refrigeration or process equipment | Required operating conditions and any safe opportunities to adjust settings. |
| Heating and ventilation | Timers, occupied periods and protection requirements. |
| Security, servers and communications | Which services must remain available and who can approve changes. |
| Lighting and ancillary equipment | Actual use outside normal hours and the relevant controls. |
| Construction equipment and cabins | Overnight requirements and whether the building programme has changed. |
Do not switch off critical equipment or alter electrical installations to test a theory without the responsible person's agreement and appropriate competence. The first task is to establish the reason for the load, not to remove it indiscriminately.
Turn an observation into a specific question
Describe the pattern, affected dates and relevant equipment. Ask the site team whether it matches an expected activity. Record their explanation alongside the graph so that a colleague can follow the enquiry later.
Hypothetical example: an office's electricity use falls after staff leave but rises again at the same time each Saturday. That could warrant checking cleaning arrangements and timed systems. It does not, by itself, prove a faulty meter or unnecessary heating.
Where a change is appropriate, record who approved it, what was adjusted and when. Compare subsequent data over a similar period, considering weather and operational differences. Avoid presenting the full before-and-after difference as a saving if other conditions changed at the same time.
If the pattern instead suggests an account or reading problem, use our bill-checking guide to organise the supplier query.
Make the review part of ongoing energy management
Assign someone to check the profile after changes to hours, equipment or occupancy. A short record of the expected background load makes later exceptions easier to spot. Keep unresolved questions separate from confirmed explanations and completed actions.
BBA Energy's energy management and supplier support can help organise consumption information and follow-up questions within the agreed service. The site team and relevant technical specialists provide the operational context needed to judge an action.
Use the capacity guide if the review also raises questions about the agreed connection requirement. Understanding when energy is used and deciding how much capacity the business needs are related but separate tasks.