Anatomy of a store's energy bill

What the bill is really made of

The electricity invoice for a business account is made up of four blocks. Only the first is negotiated on the market: the others follow tariffs set by ARERA, the Italian energy regulator, and are the same for everyone with the same type of account.

Line item	What it pays for	Negotiable
Energy	The kWh consumed, plus retail and dispatching costs	Yes, by tendering the supply and choosing between fixed and indexed pricing
Grid transport and metering	Use of the transmission and distribution grid, split into a fixed charge, a capacity charge, and an energy charge	No, regulated tariffs
System charges	The general charges of the Italian electricity system, borne by all end customers	No, regulated tariffs
Taxes	Excise duty on consumption, plus VAT	No

The practical consequence. Tendering the supplier acts on one part of the bill, not all of it. On the rest, the only lever left is consuming fewer kWh and committing less capacity. That’s why two sites with the same contract can have very different bills.

Contracted capacity, the item you pay even with the shutters down

The capacity charge is paid in euros per kW per year, regardless of how much you consume. In most retail chains the capacity was sized when the store opened and has never been reviewed since, while in the meantime the lighting has switched to LED and the loads have changed.

How to check it. Compare the contracted capacity with the maximum peak actually drawn over the last twelve months. The figure is in the invoice detail, or can be requested from the distribution company. If the peak stays consistently and comfortably below the contractual threshold, the capacity is oversized and can be reduced.

The caveat. Don’t go too low. On low-voltage connections, exceeding the available capacity trips the limiter and shuts down the store. The reduction must leave a margin, looking at seasonal peaks rather than the average.

Time-of-use bands, and the one retail works on

The price of energy changes with the time of day. The bands are defined by the regulator and apply to everyone.

Band	When	Note for a store
F1	Monday-Friday, 8 a.m.-7 p.m.	The most expensive, and the one where a store open 9 to 8 concentrates nearly all of its consumption
F2	Monday-Friday 7-8 a.m. and 7-11 p.m., Saturday 7 a.m.-11 p.m.	Covers evening opening and Saturdays, often a high-volume day
F3	Nights, Sundays, and holidays	The cheapest. How much you consume here tells you what stays on when the store is closed

Reactive power, the penalty almost nobody looks at

Motors, cold-room compressors, air handling unit fans, and power supplies draw, on top of the active energy that does useful work, reactive power that travels on the grid without producing anything. When the power factor falls below the threshold set by the regulation, specific charges kick in and appear on the invoice as a dedicated line item.

It’s a typical problem for sites with a lot of commercial refrigeration and a lot of ventilation. It’s fixed with power factor correction, a modest intervention with short payback times, which nobody schedules until they notice the line on the bill.

How to check it. Look in the invoice detail for the reactive power line item. If it shows up with recurring amounts over several months, it’s an immediate candidate.

The overnight base load, the signature of waste

The consumption a site has when it’s closed is the most honest indicator there is, because in those hours nobody is selling anything. It’s derived from consumption in band F3 relative to the closing hours, and compared with the average draw during opening hours.

A high overnight base load almost always has the same causes: HVAC that never switches to setback mode, signage and window displays with no schedule, refrigerated cases left uncovered at night, air handling units left running, an accumulation of equipment on standby.

Fixed or indexed price, and what to actually look at

With a fixed price, the value of the energy component stays locked for the duration of the contract: you pay a premium for certainty and know in advance what you’ll spend. With an indexed price, the price follows a market reference, to which the supplier adds its own margin, called the spread.

When comparing several indexed offers, the only truly comparable item is the spread, because the index is the same for everyone. Comparing the final price on the day of the offer says nothing: it changes the next day, and the difference between two offers vanishes or flips.

Question to ask the supplier	Why it matters
What is the spread, and on which index	It’s the only part the supplier actually competes on
What happens at expiry	Tacit renewal on revised terms is the most common way to lose what the tender gained
Do all sites expire at once	A single date concentrates the risk on a single market moment

Six checks to run on your next invoice

1. Contracted capacity per the contract versus the actual peak over the last twelve months.
2. Share of consumption in F3 relative to actual closing hours.
3. Reactive power charges over several consecutive months.
4. Actual versus estimated readings, and adjustments arriving months later.
5. Contract expiry date and tacit renewal clauses.
6. Consumption per square meter compared with sites of the same format.

Why it pays to do this across the whole chain at once

On a single site these checks are worth a few hundred euros and the time to run them. Across fifty sites they become a project with a return, because the same mistakes repeat identically and the fix is applied once.