How Spanish Business Electricity Tariffs Work: 3.0TD and 6.1TD

Spanish businesses do not buy electricity at a flat rate. Every supply point is assigned an access tariff determined by its connection voltage, and that tariff divides the year into six pricing periods, P1 to P6, applied to both the energy consumed and the capacity contracted. P1 is the most expensive and P6 the cheapest, and which period applies at any moment depends on the hour, the type of day, the season and the geographical electricity system.

Understanding this structure helps explain what appears on a Spanish commercial bill. It also determines how any energy investment should be evaluated, because a saving expressed as an average price per kilowatt-hour tells you very little about what a specific change will actually be worth.

Which tariff applies to a business

The access tariff is not a commercial choice. It follows from the connection.

3.0TD applies to many Spanish businesses with low-voltage supplies above 15 kW, including SMEs, larger retail units, hotels, restaurants, industrial units, supermarkets and office buildings.

6.1TD applies where the supply point connects at medium voltage, above 1 kV and below 30 kV. The tariff follows from the connection voltage rather than from the ownership of any particular equipment. Sites at this level often have a transformer associated with the supply, but the arrangements vary and the tariff does not depend on them.

Both tariffs replaced the earlier structures on 1 June 2021. The methodology is set by CNMC Circular 3/2020, subsequently amended by Circular 1/2025. Regulated charges, or cargos, are established separately by Real Decreto 148/2021, so the full regulated element of a bill is the sum of tolls and charges.

The six periods

Weekday hours on the peninsula are divided into three bands. Peak hours run from 09:00 to 14:00 and from 18:00 to 22:00. Flat hours cover 08:00 to 09:00, 14:00 to 18:00 and 22:00 to 24:00. Valley hours run from 00:00 to 08:00.

Valley hours are always P6. So are Saturdays, Sundays and national public holidays, for all twenty-four hours, in every season. P6 is the one fixed element of the calendar.

What changes through the year is which numbered period is assigned to the peak and flat bands. On the peninsula:

The Balearic Islands, the Canary Islands, Ceuta and Melilla each follow their own seasonal calendars, so a business operating across more than one system is working from more than one table. Anyone verifying a specific bill should check the calendar applicable to that supply point rather than assume the peninsular pattern.

The consequence is that the same clock hour carries a different price depending on the month. A weekday at 11:00 in January falls in P1. The same hour in June falls in P3.

What a business is billed for

Two regulated terms appear alongside the energy price agreed with the supplier.

The energy term is charged per kilowatt-hour, with a separate price in each period. The capacity term is charged per kilowatt of contracted capacity, again with a separate price in each period, and is payable whether or not the capacity is used.

The values below are the combined transmission and distribution tolls in force from 1 January 2026, set by the CNMC resolution of 18 December 2025. They are the toll component only and exclude regulated charges, the energy price agreed with the supplier and taxes.

Capacity term, euros per kW per year:

Energy term, euros per kWh:

The spread is wide. On 3.0TD the P1 capacity toll is roughly twenty-eight times the P6 figure, and on 6.1TD the ratio is larger again. Capacity contracted in the expensive periods but not actually needed therefore represents a recurring cost worth identifying.

Contracted capacity and the non-decreasing rule

Both 3.0TD and 6.1TD allow a different capacity to be contracted in each of the six periods. One constraint applies: contracted capacity must be non-decreasing from P1 through to P6, so P1 is less than or equal to P2, which is less than or equal to P3, and so on through the sequence.

That rule works in the customer's favour, because the expensive periods sit at the front. The optimisation is to bring P1 and P2 down to what the site genuinely requires rather than to reduce P5 and P6, where the toll is already low.

Under 3.0TD the earlier arrangement that billed 85% of contracted capacity when demand was lower no longer applies. Contracted capacity is the floor. A business that contracts generously and consumes modestly pays for what it contracted.

Excess capacity charges

Contracted capacity is not a hard limit. Exceeding it does not interrupt supply, but it does generate an additional charge.

The threshold is frequently reported as 105% of contracted capacity. That figure appeared in the originally published text of Circular 3/2020 and was amended to 100% by the corrección de errores published in the BOE on 19 February 2020. Excess billing therefore applies where demand exceeds contracted capacity in a period, not where it exceeds it by more than 5%.

The calculation method depends on the type of metering equipment installed rather than on the tariff itself. Supply points with metering types 1, 2 and 3 are billed under article 9.4.b.2 of the Circular, using quarter-hourly demand records combined within each period. Supply points with metering types 4 and 5 are billed under article 9.4.b.1. Excess capacity terms are published annually in Annex II of the CNMC resolution, with a separate value for each period and each tariff group, and the P1 value is many times the P6 value in every case.

The practical effect is that a short overrun during an expensive period costs substantially more than an equivalent overrun overnight or at a weekend, and that a single simultaneous start-up of several large loads can produce a charge unrelated to the month's overall consumption.

Reactive energy

Motors, transformers, compressors and some lighting draw reactive energy, which performs no useful work but loads the network. Where the power factor falls below the required level, a charge applies.

The reactive energy term applies across all periods except P6. It does not apply to low-voltage supplies with contracted capacity of 15 kW or less in all periods. Two further conditions matter. The charge arises only where reactive energy consumption exceeds 33% of active consumption during the billing period, and it is applied only to that excess rather than to all reactive energy recorded.

Inductive reactive energy is priced by power factor band, and the values in force for 2026 are:

Capacitive reactive energy in P6 is currently priced at zero where the power factor is below 0.98, though the mechanism exists in the resolution and could be given a value in future.

For a site with significant motor load and no correction equipment this can become a meaningful monthly figure. It is usually addressed with capacitor banks, and it is worth checking on recent bills before concluding that consumption itself is the problem.

Taxes on the bill

Two taxes appear on a Spanish electricity bill.

The Impuesto Especial sobre la Electricidad is levied under Ley 38/1992 at an ordinary rate of 5.11269632%, applied to the billed energy and capacity terms. It was temporarily reduced to 0.5% from 22 March to 31 May 2026 under Real Decreto-ley 7/2026, which approved a wider package of energy measures. The ordinary rate returned on 1 June 2026 and applies as at August 2026. A further mechanism allowed the reduced rate to return in August or September if electricity inflation exceeded the specified threshold. That condition was not met for August, so the ordinary rate applied at the time of review.

A reduction of 85% in the taxable base is available under article 98 of Ley 38/1992 for defined uses. These include chemical reduction, electrolytic, mineralogical and metallurgical processes, industrial activities where the cost of electricity exceeds 50% of the cost of a product, industrial activities where electricity purchases or consumption represent at least 5% of the value of production, and agricultural irrigation. The reduction is not automatic. It requires registration as a beneficiary in the territorial register with the appropriate CIE code, and businesses that qualify but have never applied do not receive it by default. A minimum charge of 0.5 euros per MWh applies to industrial uses regardless.

VAT applies at the general rate of 21% to business supplies. A temporary rate of 10% applied from 22 March to 31 May 2026 to supplies with contracted capacity of 10 kW or less and to qualifying vulnerable consumers, and the ordinary rate returned on 1 June 2026. That reduction did not extend to 3.0TD or 6.1TD business supplies above 10 kW. VAT is calculated on a base that includes the special electricity tax. For a VAT-registered business, VAT may normally be recoverable subject to the usual deduction rules.

Where the official values come from

For anything that will inform a decision, work from primary sources rather than secondary summaries, which may reproduce superseded figures.

Circular 3/2020, as corrected and as amended by Circular 1/2025, sets the tariff structure, the period definitions and the billing formulae. Real Decreto 148/2021 establishes the methodology for regulated charges. The CNMC publishes toll values annually in the BOE, with the values applicable from 1 January 2026 set by the resolution of 18 December 2025. Datadis provides eligible users with access to consumption data associated with their supply point using the CUPS reference.

Tolls and charges are regulated and identical across suppliers. They are not a point of competitive difference, whatever a commercial offer may suggest.

What this means for a solar or storage assessment

Every energy investment in Spain is evaluated against this structure, and a model built on an average annual price will misstate the result in both directions.

Solar generation occurs during daylight, which on weekdays coincides with the higher-priced periods for many businesses. The value of each self-consumed kilowatt-hour therefore depends on the period in force at that moment, the applicable contract and the variable charges that apply, and not on a blended figure.

Weekends work differently. Every Saturday and Sunday falls entirely within P6, so any weekend generation consumed on site displaces the cheapest electricity of the week and is worth correspondingly less than the same output on a weekday. For a business operating five days a week, on-site demand at weekends is also lower, so a larger proportion of weekend generation is exported or curtailed depending on the configuration of the installation. Both effects should be visible in a sizing exercise before capacity is fixed.

Solar does not reliably reduce the capacity term. Contracted capacity is billed regardless of generation, and a peak occurring under cloud cover or after dark is unaffected by the presence of panels. Reviewing contracted capacity in each period is a separate exercise, usually quicker and cheaper than a generation project, and worth completing first so that a solar case is built against a properly configured bill.

Storage economics follow directly from the period spread and from exposure to excess capacity charges. A battery proposal that does not reference tariff periods has not been modelled against the way the business is actually charged.

Reading your own data

Before committing to any change, assemble the underlying figures. Obtain the available consumption history for the supply point through Datadis, using the CUPS from a recent bill, noting that the interval and depth of data available depend on the metering installed and on the distributor's records. Map that consumption to tariff periods using the calendar applicable to the site's electricity system. Compare recorded maximum demand in each period against contracted capacity and check whether excesses have been billed. Review the reactive energy line. Establish whether the business qualifies for the reduction in the special electricity tax. Then separate the regulated elements from the energy price, which is the part open to negotiation.

Load shifting is often presented as free. It is not, because rescheduling production, pumping or charging carries operational consequences that vary by business, but where the flexibility genuinely exists it can be one of the lower-cost measures available.

That exercise produces the dataset needed to size a solar or storage system properly and may identify contract or capacity changes requiring little or no capital expenditure.

Frequently asked questions

Can a business choose its electricity tariff in Spain? No. The access tariff follows from the supply point's connection voltage and, at low voltage, from contracted capacity. What a business can choose is its supplier, its contract type and its contracted capacity in each period.

What is the difference between 3.0TD and 6.1TD? 3.0TD applies to supplies connected at no more than 1 kV where contracted capacity exceeds 15 kW in any period. 6.1TD applies to supplies connected above 1 kV and below 30 kV. Both use six periods for energy and capacity.

When does P6 apply? P6 covers 00:00 to 08:00 on weekdays plus all twenty-four hours of Saturdays, Sundays and national public holidays, in every season. It is the cheapest period and the only part of the calendar that does not vary through the year.

Why does the same hour cost different amounts in different months? Because the year is divided into seasons, each assigning a different numbered period to the same daily bands. On the peninsula, weekday peak hours are P1 in January and P4 in April. Other electricity systems follow different calendars.

What happens if a business exceeds its contracted capacity? Supply is not interrupted. Where demand exceeds contracted capacity in a period, an excess charge is calculated according to the metering type installed. The threshold is 100%, not the 105% often quoted, following the correction published in the BOE on 19 February 2020.

Can contracted capacity be different in each period? Yes. The only constraint is that it must be non-decreasing from P1 through to P6.

When is reactive energy charged? Where reactive energy consumption exceeds 33% of active consumption during the billing period, and only on that excess. The charge applies in all periods except P6, and not at all to low-voltage supplies of 15 kW or less in every period.

Does solar reduce contracted capacity charges? Not reliably. Solar reduces the energy term during generating hours but does not guarantee a lower recorded peak, since peaks can occur under cloud or outside daylight. Reducing the capacity term requires capacity review or storage with peak-shaving control.

Can a business reduce the special electricity tax it pays? In some cases. Article 98 of Ley 38/1992 provides an 85% reduction in the taxable base for defined uses, including certain industrial processes, industrial activities meeting specified electricity-cost thresholds and agricultural irrigation. It requires registration and is not applied automatically.

Reviewed 18 August 2026. Toll values, tax rates and tariff calendars are revised regularly and sometimes mid-year. The figures here should be verified against the current CNMC resolution and the BOE before being relied upon.

Internal links to add once supporting pages exist

Claude is AI and can make mistakes. Please double-check responses.