The K1-K4 capacity fee categories and the Δs coefficient
As of 27 October 2026. Rates and peak hours are announced for each year separately.
An hourly-settled business pays the capacity fee on the energy it draws from the grid in peak hours, at the rate times a multiplier A(K). The multiplier depends on the K1-K4 category that each day receives from its import profile. Below are the formula, the thresholds and a simple calculator for the category of a single day.
The Δs formula
Both averages come from the energy drawn from the grid on that day: the peak-hour total divided by the number of peak hours, and the total for the remaining hours divided by their number. On a working day that is 15 and 9 hours respectively.
Thresholds and multipliers
| Category | Δs | Multiplier A(K) | 2026 fee per kWh drawn in peak hours (PLN, net of VAT) |
|---|---|---|---|
| K1 | below 5% | 0.17 | 0.0373 |
| K2 | from 5% to below 10% | 0.50 | 0.1097 |
| K3 | from 10% to below 15% | 0.83 | 0.1821 |
| K4 | 15% or more, or no off-peak import | 1.00 | 0.2194 |
Each range includes its lower bound: a Δs of exactly 5% is K2, and exactly 15% is K4. The multiplier applies to all the energy drawn in that day’s peak hours. The 2026 rate is PLN 0.2194 per kWh, net of VAT.
What moves a day between categories
- Peak import. Lower peak-hour import lowers Δs. It also shrinks the amount the fee is charged on, whatever the category.
- Off-peak import. Higher off-peak import lowers Δs as well. This works both ways: drawing less at night can push the day into a higher category.
- Totals, not shape. Only totals and averages count, not the peak hour in which the energy was drawn. Moving grid import from 10:00 to 18:00 does not change the category.
- Hard thresholds. A day with a Δs of 14.9% has a multiplier of 0.83, while a day at 15.0% pays the full rate on all of its peak-hour energy.
- Each day on its own. Weekends and statutory public holidays have no peak hours, so no fee is charged on those days. Capacity fee hours
Calculator: the category of one day
Enter how much energy the connection drew from the grid on one working day, separately for peak and off-peak hours. The calculation runs in your browser and nothing you enter is sent anywhere. The calculator opens with an example.
- Average import per peak hour: 100.0 kWh (1500 kWh / 15)
- Average import per off-peak hour: 88.9 kWh (800 kWh / 9)
- Δs = 12.5%
Category K3, multiplier 0.83
Rule applied: Δs from 10% to below 15% → K3
Capacity fee for this day at the 2026 rate: 1500 kWh × 0.83 × PLN 0.2194/kWh = PLN 273.15, net of VAT
The calculator applies the statutory formula to the values you enter. It does not replace the operator’s settlement, which is based on meter data, and it shows no saving. Whether a connection can move to a lower category depends on its load profile and, where there is a battery, on the size of the battery relative to the peak-hour import. More in our article on how the Polish capacity fee is calculated.
Sources
- Capacity Market Act of 8 December 2017 (ustawa o rynku mocy), Article 70a; consolidated text in the Journal of Laws (Dz.U.) 2025, item 610. The K1-K4 categories were introduced by the amending act published in the Journal of Laws (Dz.U.) 2021, item 1505
- Information of the President of the Energy Regulatory Office (URE) No. 58/2025 (the 2026 rate)
This page is for information only. It is not legal advice or an offer: the law and your distribution operator’s tariff prevail.
