Half-hourly meters explained: what they are, who needs one, and how to use the data

If your site has an electrical load above 100 kW at any point during the year, your meter already records a reading every 30 minutes: 48 data points a day, 17,520 a year, whether anyone asked for them or not. Most UK organisations treat that data as a settlement formality and never open it. That is the missed opportunity.

In a recent survey, 40% of energy management professionals cited needing more data as their top barrier to hitting energy management goals, ahead of budget and staffing. Half-hourly data is exactly the granular picture those teams say they are missing. It shows demand peaks that drive capacity charges, overnight loads that should be off, and load profiles that differ site to site. The question is not whether the data exists. It does. The question is whether anyone on your team can actually use it.

This post explains what a half-hourly meter is, who is legally required to have one, and, more importantly, what to do with the data once you do.

What is a half-hourly meter?

A half-hourly meter is one configured for half-hourly settlement: it records electricity consumption in 30-minute intervals and transmits those reads automatically, giving 48 data points per day instead of a single monthly or estimated figure.

That distinction matters more than it might appear. A monthly estimated read tells you how much energy a site used over 30 days. A half-hourly data set tells you when your buildings are consuming power, how the pattern compares to last week, and whether the peak at 08:30 on Tuesday is costing you in capacity charges.

Half-hourly meters, AMR, and consumer smart meters: clearing up the terminology

These three terms are commonly confused. They refer to different things.

• Consumer smart meter (SMETS2): the current standard for homes and small businesses. It uses secure two-way communication, sending data to your energy supplier automatically while also allowing you to view real-time usage on an in-home display. It retains smart functionality when you switch suppliers.
• AMR (Automated Meter Reading): an older or more basic form of remote reading, typically used for larger commercial and industrial sites. AMR generally relies on one-way communication: the meter transmits consumption data to the supplier for accurate billing but does not feed back to the consumer for in-house monitoring.
• Half-hourly settlement meter: a billing and settlement mechanism rather than a specific physical device. It records electricity usage in 30-minute intervals and settles energy costs based on actual consumption during those periods. Both SMETS2 meters and advanced AMR meters can be configured for half-hourly settlement.

Who needs one? The P272 rule explained

For many UK businesses, this is not optional.

Sites with a maximum demand of more than 100 kW are classified as Profile Class 5–8 under the Balancing and Settlement Code (BSC). These sites are required to settle on half-hourly data under P272, a BSC modification that took effect in 2017. If your site has ever recorded a peak load above that threshold, your energy supplier should already have you settled half-hourly.

Some organisations also move to half-hourly settlement voluntarily, for the data visibility it provides rather than because of a compliance trigger.

Where the data comes from: MOP, DC, and DA

Half-hourly data does not come directly to you. It flows through a supply chain you should understand.

• the Meter Operator (MOP) installs and maintains the half-hourly meter at your site.
• the Data Collector (DC) retrieves the 30-minute reads from your meter automatically.
• the Data Aggregator (DA) consolidates those reads and passes them into settlement.

The important point is that this data already exists and flows automatically. The gap, for most organisations, is not that the data is absent: it is that they never route it somewhere they can actually use it. Your DC holds your half-hourly reads and can provide them, but raw data files are difficult to work with by hand. Energy management software handles that ingestion automatically, turning 30-minute files into something useful.

What half-hourly data reveals that monthly invoices hide

Monthly invoices are averages. They smooth out every spike, every overnight anomaly, every peak that triggered a demand charge. Half-hourly data does not. Here is what it exposes.

Peak demand and capacity charges

Capacity charges are often the line item on UK electricity invoices that most finance managers cannot explain. They are set based on your site’s maximum demand, measured in half-hourly intervals. Even a single 30-minute spike, whether from equipment start-up, an unmanaged HVAC cycle, or an uncoordinated production run, can set your capacity charge for months. If you cannot see your load profile in 30-minute resolution, you cannot manage that cost.

Overnight baseload

A well-managed building consumes very little electricity when it is empty. Half-hourly data shows exactly what your site is drawing overnight. A persistent overnight load that should be near zero is almost always a symptom of something: equipment left running, a control system fault, or processes that were scheduled but never rescheduled. Monthly reads hide that entirely.

Site-to-site comparison

Organisations with multiple sites often assume consumption differences between locations reflect differences in size or occupancy. Half-hourly load profiles tell a more specific story: one site might spike at a different time, carry a heavier base load, or recover from peak more slowly than comparable facilities. That is not a curiosity, it is a target for intervention.

How to actually use the data

This is where most teams stall. The data exists. The problem is volume.

A single site running half-hourly settlement generates 17,520 reads a year. Ten sites: 175,200. A team of six people, which is how most UK energy management functions are staffed according to State of Utilities 2026 research, cannot manually review that volume and still have time to act on what they find. The math does not work.

What changes when software does the looking: the 30-minute files come in, the load profiles are built automatically, anomalies surface as alerts rather than buried rows, and your team spends its time on decisions rather than on data management.

EnergyCAP® handles half-hourly import and analysis through Smart Analytics, the half-hourly and submeter data analysis module. It imports the 30-minute files, builds load profiles across sites, and flags the patterns worth acting on: peaks above threshold, overnight draws that should not be there, site-to-site variances that indicate a problem rather than a difference.

Customers using EnergyCAP to manage utility invoice data report an average of 7.5% in year-on-year cost savings. The platform also flags an average of 4.7% of invoices each month with issues worth acting on. Those numbers come from invoice data; half-hourly load analysis adds another layer of visibility that drives further reduction in demand-related charges.

Getting started: a short checklist

If you are not yet making use of your half-hourly data, these are the first steps.

• confirm your Profile Class: check your electricity contract or ask your supplier whether you are settled as Profile Class 5–8. If your site has ever exceeded 100 kW of maximum demand, you almost certainly are.
• confirm your Data Collector is active: your DC should already be retrieving half-hourly reads. If you are unsure who your DC is, your supplier can tell you.
• get the data into a tool that can read it: raw half-hourly files are not practical to analyse manually. Energy management software handles ingestion automatically.
• start with the two quickest wins: load your 30-minute data and look first at peak demand (what is your highest half-hour, and when does it occur?) and overnight baseload (what is your site drawing when it should be empty?). Those two questions alone typically surface the clearest targets for cost reduction.