Cutting electricity costs in cold storage under the 2025 tariff

Why is load timing important for a cold store?

Cold storage can operate through the night while still setting a large demand peak during the afternoon or evening.

Refrigeration, product loading, door activity, defrost and other processes can overlap in a way that increases the highest measured interval.

The bill prices both energy consumed and the relevant demand capacity, so reducing a blended cost-per-kWh figure is not a sufficient operating plan.

Do not assume every cold store has the same flexibility. Product requirements, equipment controls, room use, staff shifts and delivery schedules differ.

Start with the site's own load record and operating notes. A synthetic curve on a marketing page illustrates the billing mechanism;

it is not a measurement of your facility or evidence that a particular savings percentage is available.

Is Time-of-Use cheaper for cold storage?

Using the published non-domestic medium-voltage schedule, the off-peak energy break-even is 36.43% of consumption.

The demand comparison breaks even when peak-period maximum demand is 91.97% of all-hours maximum demand. These thresholds describe separate bill components.

A site with a favourable overnight energy share can still lose on the demand component if a large peak remains inside the charged window.

Reprice the same measured consumption and monthly maxima under each tariff for a representative year.

Include the applicable retail charge, fuel adjustment and other account components when reconciling complete bills. Confirm eligibility with TNB before recommending a switch.

A comparison that uses a quieter month or an assumed future schedule can misstate the value of changing tariff today.

Which operating events should I investigate first?

Identify the half-hours that set maximum demand in each billing period, then compare them with operating records.

Look for credible overlaps involving refrigeration stages, defrost, loading, cleaning, auxiliary equipment or restarts.

The interval data shows when the site load rose, but it does not prove which machine caused the change.

Equipment logs, submetering or a qualified operational review may be needed.

Compare recurring peaks with isolated incidents. A one-off event may explain an expensive month but not support an annual recurring-savings claim.

Examine whether the highest point was replaced by a nearly identical second-highest point after a proposed change.

Lowering only one interval may leave the billed monthly maximum almost unchanged if another similar overlap remains.

Can refrigeration be moved outside peak hours safely?

Some facilities may have operational flexibility, but tariff analysis is not permission to alter temperature controls.

Assess any proposed change against product limits, food-safety requirements, equipment capabilities and documented procedures. Include the people responsible for refrigeration and product quality.

Never prioritise a demand target over safe storage conditions or use a marketing calculation as an engineering instruction.

Where a change is feasible, model the whole resulting load rather than simply removing an afternoon block.

Additional pre-cooling or recovery can change energy use and create another demand peak. Monitor conditions and compare the actual revised bills with the forecast.

A credible finding states the assumptions, responsibilities and checks needed before trialling a new operating schedule.

How do power factor and maintenance affect the review?

Check whether the bills actually contain a power-factor surcharge and whether the recorded value is below the applicable TNB threshold.

If so, the next step is to identify the cause with qualified electrical support.

Do not assume that a capacitor purchase will reduce both kWh and billed kW demand. Surcharge avoidance, real-energy reduction and peak-demand reduction need separate evidence.

Existing equipment condition and controls may explain changes in the load profile, but a bill review cannot diagnose every refrigeration fault.

Treat a maintenance recommendation as a question for the responsible specialist, supported by the observed records.

Keep equipment investment separate from a no-capex scheduling option so the business can compare capital costs, operating risk and expected benefit transparently.

How can I check the bill without changing operations?

Reconcile the account, supply voltage, tariff, billed consumption, maximum demand and adjustment lines against original records.

Confirm that the billing dates align with the interval export and that meter multipliers and units are understood.

Check estimates, credits and prior balances separately from current-period electricity costs. An unusual amount needs a traceable explanation before it is called an error.

This review can establish a reliable baseline even when operations cannot be changed.

It may confirm that the current tariff is appropriate or identify a billing question for TNB.

Either result is useful, but neither justifies inventing a savings statistic.

A clear findings note should show what is supported, what remains uncertain and what additional data would resolve it.

What should I send for a cold-storage bill review?

Send a representative year of TNB bills and the matching half-hourly meter export where available.

Add concise notes about shutdowns, loading schedules, major equipment changes and unusual operating days. Avoid sharing unnecessary product or customer information.

If the export is not yet available, the bills still establish the current tariff, recorded demand and surcharge history.

Rukan reviews tariff fit, maximum demand, power factor and billing accuracy.

Findings distinguish no-capex, low-capex and capital-investment options, with the evidence for each opportunity traced to your own account records.

Multi-site operators can review their chain as one portfolio while retaining separate TNB account records for each outlet.

Start through the homepage upload card and provide consent before files are sent.