Distribution tariff selection for businesses

A distribution tariff is not inherently “better” or “worse”. The same annual energy consumption can result in different distribution costs if businesses operate at different times, have different shares of night-time and weekend consumption, different seasonality or different power levels. That is why distribution tariff selection should be based on the load profile and a cost simulation, not merely on the industry, company size or tariff-group name.

The key principle is simple: first determine which tariff groups the relevant consumption point is eligible for, then calculate each option using the same historical data. Only such a comparison can show whether changing the tariff group is economically justified.

In brief: what determines distribution tariff selection?

Before changing the tariff group, it is worth checking at least:

the voltage level and eligibility criteria for individual groups applied by the relevant distribution system operator (DSO),
the contracted capacity and the actual level of power demand,
the facility’s operating hours and the distribution of consumption over the day,
the share of consumption on working days, weekends and public holidays,
the seasonality of production or facility operation,
historical invoices and metering data,
15-minute data, if available and relevant to the option being analysed,
planned changes in operating arrangements that may alter the future load profile,
the current tariff of the relevant DSO and the contractual terms.

There is no single tariff group for a business that will be optimal regardless of how energy is used.

What is a tariff group in the context of electricity distribution?

Under Polish regulations, a tariff group means a group of customers to whom a single set of prices or charge rates, together with the conditions for applying them, applies. From a business-cost perspective, the electricity-distribution component is particularly important. The classification of customers into tariff groups takes into account, among other things, the voltage level at the point of delivery, contracted capacity, the billing system and the number of billing time zones.

This matters because, in Poland, a business cannot simply choose any group from the operator’s entire tariff. First, it is necessary to determine which groups the relevant point of delivery can qualify for under the criteria adopted by the competent energy company. If the customer meets the criteria for more than one group at a given point of delivery, one of the eligible options may be selected.

In practice, group codes may indicate, among other things, the voltage level, capacity range and number of settlement time bands, but the specific conditions, time bands and rates must always be checked in the current tariff of the relevant operator. Conclusions from one DSO’s tariff should not be directly applied to a facility located in another operator’s area.

Distribution tariff vs electricity supply offer – they are not the same thing

The distribution tariff concerns the electricity distribution service provided by the network operator and the way distribution charges are calculated. The supplier’s offer, by contrast, concerns the purchase of active energy and the commercial terms of supply.

Changing the distribution tariff group is not the same as changing the electricity supplier or selecting the price of active energy. If the objective is to compare commercial offers for active energy, that is a separate area: electricity supply for businesses.

Keeping these two areas separate is also essential when analysing an invoice. A lower active-energy price does not automatically mean lower distribution costs, while a more favourable distribution group does not change the electricity price agreed with the supplier.

Why can two similar businesses have different optimal solutions?

Consider two plants with similar operations and comparable annual electricity consumption. Comparing the number of MWh alone is not enough to identify the right tariff.

The first plant may operate Monday to Friday on a single shift, with most consumption concentrated within a few daytime hours. The second may operate around the clock, including weekends, with a relatively stable night-time load. Annual consumption may be similar, but the electricity is drawn at completely different times.

If the tariff groups being compared have different rates in individual time bands, the cost will depend on how much energy actually falls into each band. Contracted capacity, the billing method, fixed components and other elements of the relevant DSO tariff must also be taken into account.

A tariff should therefore not be selected using rules of thumb such as “manufacturing company = group X” or “round-the-clock operation = group Y”. The industry describes the process, but the bill is shaped by the actual load profile.

How do a facility’s operating hours affect distribution costs?

Distribution of consumption over the day

In multi-zone tariff groups, not only the amount of energy matters, but also when it is consumed. Two businesses using the same amount of energy per month may have different shares of consumption in daily time bands and therefore different simulation results.

The analysis should examine whether the largest loads operate simultaneously or start sequentially, when the base load occurs, and whether some processes can be shifted to other times without affecting production.

Working days, weekends and public holidays

A “typical working day” alone is not enough. A facility may have low consumption Monday to Friday but run some processes at weekends. It may operate on Saturdays only seasonally, or keep refrigeration, ventilation, a server room or a technological process running continuously even when production is stopped.

The simulation must therefore preserve the calendar of actual consumption and correctly assign each time interval to the time bands specified in the DSO tariff.

Seasonality

The load profile may change over the course of the year. Seasonal production plants, cold stores, facilities using electric heating or cooling, and businesses that operate additional lines in selected months all behave differently.

In such cases, an analysis based on a single month may lead to the wrong conclusion. It is best to use a period covering a full seasonal cycle and, where there are strong year-on-year changes, an even longer data range.

Power level and contracted capacity

Power matters for two reasons. First, contracted capacity may be one of the criteria for tariff-group eligibility. Second, the actual level of power demand and any exceedances affect part of the distribution costs.

Tariff-group analysis should therefore not be separated from power analysis. This does not mean, however, that the decision should be reduced to a single monthly maximum. What matters is the facility’s overall operating pattern, the frequency and duration of high loads, and the billing rules set out in the current DSO tariff.

What data are needed to analyse a distribution tariff?

A preliminary analysis can start with invoices. A reliable comparison of multi-zone options, however, requires an appropriately granular load profile and current tariff terms.

Data	What do they allow you to assess?
Invoices covering a full annual cycle	The current tariff group, contracted capacity, monthly consumption, seasonality and charge structure.
15-minute data	The distribution of consumption over the day, the share of energy in individual time bands, the load curve and power values.
Operating calendar	Differences between working days, weekends, public holidays, shutdowns and production periods.
Process information	The reasons for profile changes, base loads, major equipment and the possibility of shifting operation in time.
Planned changes	Whether the profile after a change in operating arrangements will still resemble the historical profile.
Current DSO tariff and agreement	Eligible groups, time bands, rates, billing rules and formal conditions for changing the group.

15-minute data are particularly useful because they make it possible to reconstruct the load curve with a level of detail that a monthly invoice cannot provide. The 15-minute interval is also relevant to power analysis: the Polish tariff regulation refers to average power values over fifteen-minute periods when defining connection capacity and contracted capacity. Such a profile is therefore a natural basis for a more detailed load analysis when the data are available.

This does not mean that nothing can be done without a 15-minute profile. Invoices may be sufficient for a preliminary assessment of whether the issue warrants deeper analysis. A decision to switch between options with different time bands should not, however, be made without data showing when the energy is actually consumed.

Qualitative example: single-shift operation vs a facility operating 24/7

Profile element	Business operating mainly on one shift	Facility operating 24/7
Main consumption hours	Consumption concentrated within a few hours of the working day.	Consumption spread throughout the day and night.
Nights	Usually a low base load.	A significant share of annual consumption may occur at night.
Weekends	Often limited operation or a shutdown.	Consumption may continue on Saturdays, Sundays and public holidays.
Importance of time bands	The result depends strongly on how operating hours overlap with specific tariff time bands.	The share of consumption in all time bands and the relationship between the constant load and the rates in those bands are important.
Risk of an incorrect assessment	An assessment based on annual MWh ignores the concentration of consumption over time.	The assumption that “24/7 operation always suits a multi-zone tariff” can be just as misleading.

Neither case allows a winning group to be identified in advance. The same actual profile must be applied to the rates and time bands of each eligible tariff group, and the result must be calculated for the full analysis period.

How to run a cost simulation before changing the tariff group

A sound analysis is not simply a comparison of one rate from a table. It should reproduce the way costs are calculated under the current option and alternative options using the same input data.

1. Determine which groups the facility is eligible for

The starting point is the connection conditions, voltage level, contracted capacity, metering and billing system, and the criteria in the current tariff of the relevant DSO. Comparison options are created only from the eligible groups.

2. Reconstruct the actual load profile

Metering data should be assigned to the correct days and hours. In multi-zone tariffs, each interval should be assigned to the appropriate time band in accordance with the calendar and the DSO’s rules.

3. Calculate the full distribution cost for each option

The comparison should include all components of the distribution bill that apply to the relevant consumption point under the current tariff. Conclusions should not be drawn from a single variable rate or one parameter alone.

The safest method is to run the same historical profile through the current and alternative options. This ensures that the difference results from the tariff structure rather than from comparing two months with different consumption levels.

4. Check the result by month and season

An annual result can hide periods in which a given group performs very differently. It is therefore worth checking production months, shutdowns, summer and winter seasons, and atypical periods.

5. Add a future-operation scenario

If the business plans to introduce a second shift, extend weekend operation, start a new line or make a material technology change, historical data alone may not be representative. In that case, an option reflecting the planned operating arrangement should also be calculated.

6. Verify the formal conditions for changing the group

Under the rules currently in force in Poland, a customer eligible for more than one group may request a tariff-group change no more than once every 12 months. Where charge rates change, the regulations also allow a request within 60 days from the date the new tariff enters into force. The detailed conditions are set out in the relevant agreement.

This is another reason not to make the decision on the basis of a superficial comparison: an unsuitable option cannot always be corrected immediately.

Why can a change in operating arrangements affect tariff economics?

Tariff-group selection is an assessment made for a specific profile. If that profile changes, the previous decision may cease to be optimal.

The most common changes worth including in a reassessment are:

moving from one shift to two or three shifts,
starting or reducing weekend operation,
shifting the start times of the largest loads,
starting a new line or shutting down part of production,
increasing the base load outside operating hours,
a significant change in seasonality,
changing the contracted capacity or the way capacity is used,
a change in the DSO tariff and rates.

The result of the analysis should therefore not be treated as a decision “for ever”. After a major organisational change, it is worth checking again whether the historically favourable option still matches the way the facility actually consumes electricity.

When is it worth analysing a tariff-group change?

An analysis is particularly useful when:

the tariff group was selected many years ago and the facility’s operating pattern has changed since then,
the business has increased the share of night-time or weekend consumption,
an additional shift or a new production line has been introduced,
annual consumption remains similar but its distribution over time has changed,
there is clear seasonality,
the business has several electricity consumption points (PPE) with different load profiles and all are billed under a similar arrangement,
no one has previously run a simulation using metering data,
a new DSO tariff has entered into force or rates have changed and the options should be recalculated.

A broader bill analysis should also cover electricity distribution cost optimisation, because the tariff group is only one cost component. Contracted capacity, exceedances, reactive energy and other billing items may require separate assessment.

Auditor’s comment: a tariff-group change should result from a cost model, not intuition. The biggest mistake is to compare group names or individual rates without checking the hours and days when the business actually consumes electricity. With the same number of MWh, a different distribution of consumption can lead to a completely different conclusion.

Frequently asked questions

Is a multi-zone tariff always cheaper for a business?

No. The outcome depends on the share of consumption in individual time bands, the relevant DSO rates, power demand and the other billing rules. Without a simulation based on the actual profile, this cannot be determined reliably.

Is an invoice enough to select a tariff group?

An invoice is sufficient for a preliminary review of the current terms and cost structure. If the comparison concerns groups with different time bands, a reliable simulation requires data showing how consumption is distributed over time – preferably interval data covering a representative period.

Does changing the tariff group mean changing the electricity supplier?

No. The tariff group concerns the way distribution is billed. The supplier’s offer for active energy is a separate cost component and can be analysed independently.

Will a tariff group, once selected, remain suitable for years to come?

Not necessarily. Changes in operating hours, the number of shifts, weekend production, seasonality, power demand or the DSO tariff itself can change the result of the comparison. After a material change in the profile, the analysis should be repeated.

Summary

Distribution tariff selection should not start with the question “which group is the cheapest?”, but with “when does our facility consume electricity and at what power levels?” Only after combining the load profile, historical data, operating calendar, power demand and the current DSO tariff can the eligible options be compared reliably.

A business operating mainly on one shift and a facility running 24/7 may have similar annual consumption yet yield different results in the tariff analysis. Before changing the group, it is therefore worth simulating the full distribution costs and checking whether planned changes in operating arrangements could alter the conclusions drawn from historical data.

Sources

Legal status as of 2 September 2026. Before changing the group, check the current tariff of the relevant DSO and the terms of the specific agreement

Services for Businesses

Audits and Energy Efficiency

Investments and Compliance

Energy Procurement and Costs

Distribution tariff for a business – when can changing the tariff group reduce costs?