Smart Meter Data for Commercial Buildings: What It Reveals and What It Misses

What does commercial smart-meter data show?

Commercial smart-meter or half-hourly data normally records electricity consumption in 30-minute periods.

In practical terms, this allows you to build a daily energy profile for the building.

You can see:

• when electricity use begins to rise;
• when the building reaches its normal daytime load;
• when consumption falls after closing;
• how much electricity is being used overnight;
• whether weekends differ from weekdays;
• whether bank holidays and shutdown periods look genuinely different;
• how consumption changes between summer and winter;
• whether a change to plant or controls has altered the profile.

This is far more useful than looking only at monthly energy bills.

A monthly bill tells you how much electricity the building used overall. Half-hourly data shows how and when that electricity was used.

Most suppliers can provide the information as a spreadsheet or CSV file. It can then be reviewed in Excel using simple charts.

If you do not know whether your building already has half-hourly electricity data, ask your supplier. Where suitable metering is not yet installed, ask what options are available.

Gas data is usually less detailed

Half-hourly gas metering is much less common.

Gas use is therefore often harder to analyse in the same detail. In many buildings, the best available information may still be monthly bills or manual meter readings.

Because of this, heating schedules and Building Management System settings need particularly careful attention.

A useful practical check is to read the gas meter when the building closes and again when it opens the following morning.

In many ordinary commercial buildings, overnight gas use should be close to zero outside the heating season. Unexpected overnight consumption may indicate:

• boilers running too late;
• heating starting too early;
• hot-water systems operating unnecessarily;
• frost-protection settings that are too high;
• poor BMS schedules;
• overrides that have not been removed.

Even a simple overnight meter check can provide useful evidence before a more detailed building energy assessment or audit is commissioned.

Understanding the daily electricity profile

A healthy commercial-building electricity profile often looks more like a set of steps than a smooth curve.

For a conventional office, you would normally hope to see:

• a low and stable overnight baseload;
• a fairly sharp increase around opening time, or perhaps shortly before;
• a stable daytime operating level;
• a clear fall around building close;
• a return to the overnight baseload.

A good profile broadly reflects how the building is actually occupied and used.

A poor profile may look more like a broad curve:

• electricity use begins rising at 3am;
• the building reaches full load long before anybody arrives;
• consumption remains high after people leave;
• demand drifts slowly down towards midnight;
• weekends look similar to working days.

That shape often points to overextended schedules, poor control or equipment operating when it is not required.

How quickly does the building ramp up?

The start of the working day is highly informative.

For many offices, the main rise in electricity demand should begin reasonably close to occupancy time. Heating, ventilation or cooling systems may need to start earlier, but the lead time should be understood and justified.

A building that opens at 8am does not normally need to be at full electrical load by 3am.

Early starts may be caused by:

• BMS optimisation settings that are not functioning properly;
• exaggerated warm-up periods;
• copied factory schedules;
• controls designed for a different occupancy pattern;
• equipment left running continuously.

The same principle applies at the end of the day.

A well-controlled building should usually show a noticeable reduction in load around closing time. If the profile declines slowly over several hours, equipment may be switched off manually and inconsistently, or different systems may have unnecessarily long run-on periods.

Identifying overnight baseload and after-hours energy waste

One of the clearest uses of half-hourly data is measuring overnight electricity demand.

Commercial buildings rarely reach zero because some equipment genuinely needs to remain operational, including:

• fire and burglar alarms;
• emergency lighting;
• servers and network equipment;
• refrigeration;
• specialist monitoring systems;
• essential process or environmental equipment.

The objective is not necessarily to reach zero. It is to establish a realistic and explainable target baseload.

A useful investigation normally involves:

1. finding the average overnight electrical load in kilowatts;
2. estimating the equipment that genuinely needs to remain on;
3. calculating the unexplained difference;
4. estimating the annual cost of that avoidable load;
5. carrying out a planned hard switch-off night;
6. checking how far the overnight load falls;
7. investigating anything that remains unexplained.

Common sources of avoidable overnight electricity use include:

• pumps;
• fans;
• computers and monitors;
• split-system heat pumps;
• electric radiators;
• kitchen equipment;
• display equipment;
• many smaller plug loads adding up.

A focused investigation into out-of-hours energy use can often deliver substantial savings without affecting occupants or the normal performance of the building.

Weekdays, weekends and shutdown periods

Half-hourly data makes it easy to compare different types of day.

This matters because many buildings continue operating almost normally at weekends despite being empty.

A common fault in Monday-to-Friday offices is that weekday BMS schedules have simply been copied across to Saturday and Sunday.

The building then heats, cools and ventilates itself throughout the weekend because the calendar has not been configured correctly.

Compare:

• Monday to Friday;
• Saturday and Sunday;
• bank holidays;
• Christmas shutdowns;
• planned closure periods.

If Christmas Day looks almost the same as a normal working Tuesday, something is probably wrong.

Shutdown periods are particularly valuable because they show the minimum load the building can realistically achieve.

Seasonal changes in overnight energy use

Overnight consumption should also be compared across the year.

A night load that rises sharply in winter may reveal electric heaters being left on.

Oil-filled radiators and portable electric heaters are common causes because they often sit outside the main BMS and rely on occupants remembering to switch them off.

Seasonal changes may also reveal:

• trace heating;
• frost protection;
• circulation pumps;
• local heat pumps;
• increased server-room cooling;
• external lighting schedules;
• electric hot-water systems.

A stable year-round baseload is generally easier to explain. A large winter increase deserves investigation.

Spotting unusual peaks and operational changes

Smart-meter data can reveal sudden changes in building operation.

For example:

• a new item of equipment causes a permanent increase;
• a control change leads to earlier morning starts;
• an event override is never removed;
• a fault causes a fan or pump to run continuously;
• temporary electric heating becomes permanent;
• a building stops responding to a seasonal control change.

The most useful approach is not only to review current data, but to compare the profile before and after important changes.

If a contractor changes the BMS, replaces plant or adjusts schedules, the half-hourly profile should be checked afterwards.

You should be able to see whether the intervention actually improved performance.

What smart-meter data cannot tell you

A main electricity meter shows the total electricity entering the building.

It cannot usually identify exactly which equipment caused a particular load.

A 20 kW overnight demand might represent:

• ten electric heaters;
• a large ventilation system;
• several pumps;
• server-room cooling;
• a mixture of dozens of smaller loads.

The profile provides clues, but not always the answer.

Interpretation depends on context:

• occupancy;
• weather;
• operating hours;
• building type;
• heating and cooling systems;
• major equipment;
• recent changes;
• events or maintenance work.

That is why a meter chart should not be analysed in isolation.

A useful diagnosis normally combines the data with:

• knowledge of the building;
• discussions with facilities and operational staff;
• BMS and local control schedules;
• equipment ratings;
• a physical site inspection;
• sometimes an overnight audit.

Smart-meter data can show that a problem exists. A building energy audit is often what connects the pattern to its physical cause.

Are more submeters always better?

No.

Submetering can be useful, but many organisations install large numbers of meters without first deciding what question they are trying to answer.

I have seen extensive submetering programmes where the data was never meaningfully reviewed.

The problem is not only the cost of the equipment. It is the continuing time required to:

• collect the data;
• check whether the meters are working;
• understand what each meter serves;
• analyse the profiles;
• investigate anomalies;
• respond to what the data shows.

A submeter labelled “Distribution Board 5” may serve two floors, lighting, plug loads and miscellaneous equipment. Its profile then looks much like the main building meter and provides very little additional understanding.

Poorly chosen submeters create more data without creating more insight.

Examples of potentially low-value submetering include:

• individual lifts;
• mixed distribution boards;
• small miscellaneous circuits;
• trivial loads with little influence on total consumption.

Use the 90:10 principle

In many estates, the majority of energy use is concentrated in a relatively small proportion of the meters, buildings or major loads.

The sensible approach is therefore to:

• use the existing main half-hourly meter data fully;
• identify the largest buildings and loads;
• add a small number of targeted meters where they answer a specific question.

Submetering can be valuable where:

• separate buildings need to be compared;
• tenants must be invoiced;
• a large chiller or process load needs investigation;
• a significant item of plant is suspected of wasting energy;
• one part of an estate dominates consumption.

Splitting an estate by building is often useful because it creates a meaningful building-level profile.

Installing meters everywhere and deciding what to do with the data later usually is not.

Why submetering programmes often fail

Many submetering programmes fail for one simple reason:

Nobody has been given the time and responsibility to review the data.

Meters do not save energy.

Data platforms do not save energy.

Dashboards do not save energy.

Savings happen when somebody:

• reviews the data;
• understands the pattern;
• investigates the cause;
• changes the controls, operation or equipment;
• checks that the change worked.

Without that energy-management process, even an expensive monitoring system can become little more than electronic wallpaper.

When is an on-site energy audit needed?

Smart-meter data is often enough to show that a problem exists.

It is not always enough to identify the cause.

An on-site commercial building energy audit becomes useful when:

• overnight load is high but unexplained;
• heating or cooling starts too early;
• weekend use is excessive;
• profiles change without an obvious reason;
• major plant appears to be operating unnecessarily;
• the building has complex or poorly understood controls;
• the organisation is considering new equipment or submetering;
• an energy audit report is needed to turn the evidence into prioritised actions.

The audit links the energy profile to the physical building.

It answers the question:

“What is actually causing this pattern, and what should we do about it?”

Turning building energy data into action

A practical smart-meter review should lead to a short list of actions, not a larger collection of graphs.

Typical actions might include:

• correcting weekday and weekend BMS schedules;
• reducing morning warm-up periods;
• switching off pumps and fans outside occupied hours;
• disabling or controlling portable electric heating;
• installing time clocks;
• using last-person-out switches;
• checking controls after events;
• monitoring overnight demand weekly;
• adding one targeted submeter for a major load;
• carrying out an overnight energy audit.

The best meter data is not necessarily the most detailed data.

It is the data that leads to a useful decision.

Start with the meter you already have

Before buying new meters, dashboards or monitoring systems, find out what data is already available.

Ask your electricity supplier for the half-hourly readings. Put them into Excel. Plot a normal weekday, a weekend, a bank holiday and a winter night.

Look for:

• early starts;
• late finishes;
• weekend operation;
• high overnight baseload;
• unusual seasonal changes;
• sudden increases;
• failure to respond to control changes.

In many commercial buildings, the main meter already contains enough information to identify the first and most valuable energy-saving opportunities.

The smart meter will not tell you everything.

Used properly, however, it can tell you where to start.