Six steps, one final price
This is how the price of every kWh is built today: starting with the cost of buying the energy itself, then adding what it costs to transport it, maintain the system, the supplier's management fee and taxes. Illustrative amounts per kWh, 3.0TD tariff, a business with 80 kW contracted.
Time bands by tariff
Steps 2 and 3 (tolls and charges) are split into different time periods across the day and the year. Here's how each tariff organizes them:
2.0TD — households and small businesses (up to 15 kW)
Same split all 12 months of the year, for both energy and power.
Energy · 3 periods
Monday to Friday
weekdays
Saturdays, Sundays
and holidays
Power · 2 periods
Monday to Friday
weekdays
Saturdays, Sundays
and holidays
3.0TD and 6.XTD — 6 periods, same split for energy and power
The hours of the day don't change; what changes by month is which period number applies to them, as the clocks show.
High season
Jan · Feb · Jul · Dec
Mid-high
Mar · Nov
Mid
Jun · Aug · Sep
Low
Apr · May · Oct
Weekend
and holidays, all year
Three real bills, step by step
The same process, applied to three consumption profiles. Market prices and tax rates are those in force in October 2026; the supplier's margin and the system charges are illustrative estimates, since each company sets its own and they aren't published openly.
From 15 kW contracted upward —workshops, small supermarkets, mid-sized businesses— you move to the 3.0TD tariff, and from a certain connection voltage, to the 6.XTD tariffs used by large factories. The six-step process is the same, but with three differences: six time periods (P1 to P6) instead of 2-3, reactive energy if the machinery isn't efficient, and many contracts indexed hour by hour.
An average household
A small business
A higher-power business
Two surcharges a household never sees: reactive energy and excess power
On 3.0TD and 6.XTD there are two more concepts that can be added to the six steps above, and that don't exist on a 2.0TD tariff (up to 15 kW). Both come from the same device: the maximeter, which records what actually flows through the installation every 15 minutes, not just what was contracted.
When machinery isn't "clean"
Motors, compressors or fluorescent lighting draw reactive energy: it travels through the grid but doesn't do any useful work. If reactive energy exceeds 33% of active energy in the same period (equivalent to a power factor, cos φ, below 0.95), the excess is billed separately — the worse the cos φ, the higher the price.
When more than contracted is drawn
The maximeter measures actual power every 15 minutes. A single 15-minute interval above the power contracted for that period is enough to trigger a surcharge on the power term — and the regulations treat supplies up to 50 kW differently from those above 50 kW.