Supermarkets and Convenience Chains
In a supermarket the cases and cold rooms run day and night, so the night load is never zero. The real question is how much of it is refrigeration and how much is lighting, heating or air conditioning that never switched off.
Night load
Is the night load normal?
When a supermarket closes, the power does not go off. Chilled cases, cold rooms and freezers run all night. So the night load of a store never falls to zero, and a single figure cannot tell you whether it is normal.
The answer comes from separating refrigeration from everything else. With the refrigeration board metered on its own, what remains overnight should be security, emergency lighting and tills. Every kilowatt above that base is a heating or air conditioning group, a sign or a lighting circuit that stayed on.
- Refrigeration and general circuits tracked separately
- Night base compared with stores of a similar format
- Stores above the base flagged at night and listed in the morning
The remote control module then puts lighting, signage and HVAC on the trading calendar, including Sunday trading hours and bank holidays, with external lighting on an astronomical timer. Refrigeration is never scheduled, only monitored.
A Store Day
general circuits · refrigeration excluded7.8avg closed kW
+48.9kWh excess · per night
07–22 open closed hours night base in similar stores 2.4 kW load above base
Refrigeration
Refrigeration drifts quietly
A chilled case costs most not when it fails but when it slowly gets worse. A door that does not close fully, a night blind left up on an open case, a condenser coated in dust: the product is still cold, the store just pays more to keep it that way.
At one store the drift is too small to see on a bill. With the refrigeration board metered, each store is compared with its own history and with stores of the same format. Whether the drift grows at night or in the warm afternoon narrows down the cause.
- Drift that grows overnight: doors, night blinds, seals
- Drift that grows in warm hours: condenser and airflow
- The same drift every day: a setpoint or controller change
Nobody needs to open a report to read this. You ask Enver, the AI assistant, in a plain sentence; the answer names the data it rests on and tells the site team what to check.
Assistant
from the measurement record-
Which stores drifted on refrigeration last week?
- Enver
Two stand out. Store 112 runs 22% above similar stores on the refrigeration board, but only at night: the drift starts straight after closing and is normal during trading, which points at night blinds left up on open cases. Store 087 is normal at night but 18% high in the warm afternoon hours, which points at a dirty condenser or blocked airflow. Both need a site check; neither looks like a setting that can be changed remotely.
- refrigeration board half-hourly · 14 days
- stores of the same format
- outdoor temperature
Timing
The trading peak meets the red band
DUoS charges follow time-of-use bands, and the red band is the most expensive. Its hours depend on the network region, so a chain spread across the country does not have one red band but several.
A supermarket’s busiest trading often falls in the late afternoon and early evening, right where red bands tend to sit. Half-hourly data shows how much of each store’s consumption lands inside its own red band, and which stores sit well above others of the same format.
- Red-band hours set per store from its DNO region
- Red-band share calculated from each store’s own half-hourly data
- Stores ranked within their format group, not against the whole estate
Refrigeration has to keep running through the red band. The useful question is what else does: HVAC pre-conditioning, bakery equipment, lighting groups. Those can often be moved or staggered by schedule. The red band guide explains how the bands work.
Red-Band Exposure
by store · last 3 months| Store | Format | kWh in red band % | Above format avg pts |
|---|---|---|---|
| Store 014 | Superstore | 13 | 0.4 |
| Store 052 | Convenience | 19 | 4.9 |
| Store 087 | Superstore | 12 | 0.0 |
| Store 131 | Convenience | 21 | 7.7 |
| Store 201 | Supermarket | 14 | 1.1 |
Capacity and bills
Hundreds of small supplies, one check
Every store has an agreed supply capacity in kVA, and it is rarely sized with care. Many stores carry far more capacity than they ever use and pay for it every month. A few run close to the limit, and a hot week or a new chiller tips them into excess capacity charges.
Half-hourly data settles this store by store: the highest demand actually drawn, set against the agreed figure. The same record feeds bill validation. Each bill is recalculated from metered data and checked line by line: unit rates by band, standing and capacity charges, Climate Change Levy. Lines that do not match go on a list with the reason.
- Maximum demand compared with agreed capacity per store
- Every half-hourly bill recalculated from metered data
- Mismatched lines listed with the reason, ready for the supplier
Reactive charges also appear on half-hourly bills when power factor drops below 0.95. At most stores the line is small, but the power quality screen shows where it recurs, along with harmonics and imbalance. More in the guides on agreed capacity, checking a half-hourly bill and reactive charges.
Agreed Capacity
by store · 12 months| Store | Agreed kVA | Max demand kVA | Utilisation % |
|---|---|---|---|
| Store 014 | 400 | 312 | 78 |
| Store 052 | 120 | 49 | 41 |
| Store 087 | 350 | 371 | 106 |
| Store 131 | 100 | 38 | 38 |
| Store 201 | 250 | 207 | 83 |
Alarms and maintenance
The right alarm to the right person
The same event means different things to different people. A heating group left on overnight is the store manager’s job. The area manager wants the picture across the area. Capacity, generator readiness and refrigeration drift go to facilities. Sending everything to everyone ends with nobody looking.
In the alarm centre each rule has recipients defined by role: head office, area manager, store manager, facilities. Notifications go by email and WhatsApp, and a closing message follows when the event clears.
- Recipients by role: store, area, facilities, head office
- Test reports for stores with a standby generator
- Planned maintenance set against what was actually done
At larger stores with a generator, each test is recorded with its duration, load and result, and fuel level is visible centrally. Maintenance compares the plan with the record: a condenser clean that is planned but never logged stays open as a task.
- Yesterday
- Night load — Store 112 General circuits drawing 7.8 kW after closing; night base in similar stores is 2.4 kW. HVAC group appears to be on. To: store manager, area manager Open panel
- Back to normal — Store 112 General circuits 2.6 kW. Time left on: 1 h 25 min.
- Today
- Capacity — Store 087 Demand 371 kVA against 350 kVA agreed. To: facilities Open panel
- Generator test — Store 201 Duration 30 min, load 58%, 400 V / 50.0 Hz. Result: passed. Open report
Which modules work in a supermarket chain
| Module | What it does here |
|---|---|
| Energy Consumption | Night load, refrigeration board, store comparison and estate map |
| Bill Validation | Every half-hourly bill recalculated from metered data, capacity checks |
| Power Quality | Power factor, reactive charges, harmonics and imbalance |
| Remote Control | Trading calendar for lighting, signage and HVAC, astronomical timer |
| AI Assistant | Sourced answers to “which store drifted on refrigeration” |
| Standby Power | Generator readiness, test reports and fuel at larger stores |
| Chiller and Cooling | Efficiency tracking at larger stores with chillers |
| Energy Performance and ISO 50001 | Estate-wide baselines, CUSUM and reporting |
Start with what is metered, grow region by region
Most stores already have a meter or analyser on the main board, and the panel starts from that. Half-hourly data is enough for red-band exposure, capacity and bill checks. Separating refrigeration, getting night alarms and putting signage on a schedule need a metering point on the refrigeration board and a control device at the store.
The estate map makes the order easy to choose. Stores appear on a map of the country, and those with high night load, capacity issues or bill mismatches are marked. One region goes live first; once the night load and bill lists are seen to work, the rest of the estate follows.
For the largest grocers, ESOS Phase 4 adds a deadline. Companies with 250 or more employees, or turnover over £44m and a balance sheet over £38m, on 31 December 2026 must notify by 5 December 2027, and the audit has to cover 95% of energy. That means data from every store, not a sample. The panel holds a measured electricity record per store, and ISO 50001 is an alternative route, with baselines and CUSUM in the energy performance module. The same record supports annual SECR reporting. See the ESOS Phase 4 guide.
Where supermarkets, stores and branches sit under one management, the shared approach is on the retail chains page. For prices by store count and module, see pricing.
Frequently asked
A store has high night load. Is it refrigeration or HVAC?
Metering the refrigeration board separately answers that. If refrigeration is within its usual band, the extra load comes from the general circuits: HVAC, signage or lighting left on. If the refrigeration board is drifting, the cause is usually doors, night blinds or the condenser.
Do we have to install devices in every store?
No. Stores with an existing meter or analyser on the main board start from that, and half-hourly data covers red-band, capacity and bill checks. A metering point on the refrigeration board and a control device are added where you want refrigeration tracked separately or schedules run remotely.
Red-band hours differ by region. How is that handled?
Each store is assigned the time bands of its own network region, so red-band exposure is calculated against the right hours for that store rather than one national window.
Does this help with ESOS Phase 4?
The audit must cover 95% of energy, so data is needed from every store. The panel keeps a measured electricity record per store, and baselines and CUSUM support ISO 50001 as an alternative route.
How is the price set?
Price depends on the number of stores and the modules chosen. Details on the pricing page.
Let us measure what is happening on your site.
In a one-hour call we look at your existing setup and set out exactly which measurement points are needed and what you would be able to see.