December 2025 - One fifth of electricity from gas

Electricity production

Production from renewable energy sources  

In December, 3.5 TWh (22.4%) of the electricity produced came from renewable sources. This represents a decrease of 2.2% compared to November 2025 and 9.0% compared to December 2024. This is one of the weakest RES results this year and is due to seasonally lower PV production and poor wind conditions.

According to estimates by Forum Energii, wind farms produced 2.1 TWh of electricity (61.2% of RES generation) in December 2025. This is 19.3% less than in December 2024, but 16.3% more than in November 2025. The rate of growth in wind power capacity has slowed significantly, raising concerns about energy availability during winter periods. The installed capacity of wind farms at the beginning of December (latest data) was 11.2 GW, an increase of 5.1% y/y or 545 MW per year. Throughout 2025, wind farms produced 23.6 TWh of electricity, a decrease of 4.5% compared to 2024, despite higher installed capacity. This is mainly due to poorer wind conditions.

In December, PV installations produced 0.4 TWh (11.7% of renewable energy generation), which represents a 40.6% month-on-month decline in production, but a 73.6% year-on-year increase. The rate of growth in PV capacity has been equally dynamic for the last three years. Currently, most of the new capacity no longer comes from prosumer installations, but from large-scale photovoltaics. The installed PV capacity at the beginning of November (latest data) was 25.4 GW (an increase of approx. 23.1% y/y or approx. 4,764 MW per year), of which approx. 12.9 GW were prosumer installations (an increase of 8.9% y/y or 1,051.3 MW per year). Throughout 2025, PV installations produced 20.5 TWh, which is 14.7% more than in 2024.

Biomass installations produced approx. 0.8 TWh in December, and hydroelectric power plants 0.2 TWh.

The maximum hourly share of weather-dependent RES (wind and solar) in domestic electricity production reached 46.9% in December, while the minimum was 0.8%. In turn, the largest hourly share of these sources in electricity consumption was 56.5%.

In the Polish power system, the share of RES in electricity consumption (i.e. the ratio of RES generation to total production from all sources plus imports and storage) is usually higher than the share of RES in production. In situations where the total power supplied in a given hour is higher than the current demand, it is necessary to use electricity storage facilities, export surplus energy, or even shut down RES sources.

In December, the system operator was forced to curtail RES generation units for 89 hours (12% of the hours in the month) over 11 days. These situations occurred mainly at night.

The generation of 31.6 GWh of electricity was curtailed, which is 3.2% more than in November 2025. Almost all of this concerned wind energy (1.5% of potential production), of which 17.5 GWh, or 55.5%, occurred in the last week of December, i.e. between 28 and 31 December. The total restrictions on renewable energy sources in 2025 amounted to 1,378.7 GWh. For comparison, 731.4 GWh was restricted in the whole of 2024.

The graphshows cumulative annual values (from the beginning of the year to the last day of the reported month) of non-market redispatching (so-called curtailment) of electricity from wind and solar farms (which has not yet affected prosumers). Curtailment, meaning the forced reduction of electricity production by the transmission system operator (PSE), has so far been implemented solely for balancing reasons — i.e. due to excess electricity generation relative to demand and limited storage or export capacity — rather than due to grid constraints.

The purpose of curtailing generation is to prevent the national power system (KSE) from losing its regulatory capacity, which could otherwise lead to a deterioration in network security and stability parameters.

It is worth noting that the volume of curtailed renewable energy would be lower if conventional power sources — coal and gas-fired power plants and CHP units — were more flexible, i.e. had lower technical minimums and could ramp up or down more quickly. The curtailment could also be reduced if the Polish power system had more energy storage facilities or made greater use of demand-side flexibility — that is, loads capable of increasing consumption when electricity prices are low (typically during high renewable output), such as electrolyzers or heating devices charging thermal storage systems.

For most of the year, curtailment mainly affects large-scale photovoltaic installations. In winter, wind farms produce more electricity, so a change in the curtailment structure can be expected. However, due to poor wind conditions in November, both wind energy production and curtailment were low. The chart below shows how the structure of RES curtailment changes between PV and wind power plants. A seasonal change is visible, when wind begins to play a greater role in the mix, while photovoltaic production declines.

Such a high level of reduction in renewable energy generation is a result of the need to maintain the stability of the power system, the low flexibility of coal-fired power plants, and the need to keep them operating at minimum technical capacity.

Production from fossil fuels 

In December 2025, gas-fired power plants and combined heat and power plants produced a record 3.2 TWh of electricity (an increase of 14.6% month-on-month and 33.3% year-on-year), which translates into 20.4% of the electricity produced. This is the highest result in history, and the share of gas fuels in the electricity mix exceeded 20% for the first time. Just a year earlier, gas fuels were used to produce approximately 15% of electricity. The year 2025 was the best period in history for gas-fired power plants in terms of electricity production. Since the beginning of the year, they have produced 26.8 TWh, which is 21.7% more than in 2024.

Production from hard coal fell by 3.2% compared to December last year and increased by 5.5% compared to November 2025 (to 6.1 TWh). Production from lignite reached 2.8 TWh. This is a decrease of 15.9% y/y and 2.5% m/m. Once again, most of the electricity in Poland came from coal, i.e. 8.9 TWh (56.9% of the mix). This is an increase of 2.9% month-on-month but a decrease of 7.6% year-on-year. Annual energy production from coal was lower than in 2024. A total of 57.3 TWh was produced from hard coal (a decrease of 3.1% compared to 2024) and 33.5 TWh from lignite (a decrease of 7.1% compared to 2024).

 The graph shows the electricity generation mix in Poland by different technologies using fossil fuels or renewable sources. The primary source of electricity is hard coal and lignite, but the share of natural gas and RES continues to grow. Depending on the season, wind power or photovoltaics provide the most energy among renewable sources. 

The changes in the structure of electricity generation that have taken place in recent years are unprecedented. Between December 2015 and December 2025, the share of coal in the mix decreased by 19.0 percentage points. The systematic development of renewable sources means that the difference between energy production from coal and from RES is decreasing at an ever faster rate.  In addition, large natural gas units are beginning to play an increasingly important role.

However, significant seasonal differences are still evident, with RES generation remaining significantly lower in winter. This is mainly due to higher energy demand and the limited pace of development of onshore wind energy, which could significantly increase production in months with low solar generation. The slowdown in the development of new wind power capacity translates into greater dependence of winter generation on conventional sources.

The graph shows how the monthly shares of each source's electricity production in total production have changed over the past few years.

December 2025 - details

• The average monthly power demand in December 2025 was 19.5 GW (0.5 GW more than in December last year), reaching a maximum of 24.9 GW (minimum – 13.3 GW).
• Electricity consumption amounted to 14.5 TWh (2.6% more than a year earlier), while gross production amounted to 15.7 TWh (1.7% less y/y).

The power demand in the Polish power system varies between 10 GW and 28 GW. The average value illustrates the system situation in a given month. By observing the monthly minima and maxima, it has so far been noticeable that the summer months are characterised by significant power demand variability and high demand peaks around midday. However, these profiles are now changing, due to the dynamic emergence of heat pumps, which increase demand during the winter months, and air conditioners and photovoltaic installations, whose greatest impact can be observed during the summer months. 

• Net electricity imports amounted to 0.3 TWh, i.e. 2.1% of domestic demand.
• Most of the imported electricity came from Germany (1.2 TWh) and Sweden (0.4 TWh). In turn, the largest net exports were to the south, i.e. 0.7 TWh to the Czech Republic and 0.6 TWh to Slovakia.

In the graph we observe the physical cross-border exchange of electricity, i.e. from which country we import and to which country we export energy in a given period. Addition values indicate that imports were the main direction in a given month and a negative value indicates that energy was mainly exported. Physical exchanges can be forced by system conditions or result from trade flows. The direction of electricity trade is mainly influenced by the price difference in the markets (energy flows from a country with a lower price to a country with a higher price). Cross-border exchanges with Germany, the Czech Republic, Slovakia, Sweden and Lithuania take place within the Single Day-ahead Coupling, as well as inter-operator exchanges. The exchange with Ukraine, which became possible from May 2023 thanks to the ENTSO-E decision, takes place within the framework of unilateral monthly auctions announced by PSE. Previously, the exchange only took place unidirectionally from Ukraine to Poland on the Zamość-Dobrotwór connection. Energy exchange with Sweden and Lithuania takes place via a direct current connection (HVDC). The electricity systems of the other countries are synchronised, hence the exchange takes place using alternating current lines (HVAC) and these are physical (not commercial) flows. 

• Electricity generation from renewable energy sources accounted for 22.4% of the generation mix, down by 1.8 percentage points compared to December 2024.

The graph shows the share of renewable electricity in total production for a given month and year. The share of renewables in consumption may differ minimally from the visible values due to imports and exports. Since 2015, an expansion of wind sources is visible (higher % of RES in autumn and winter), while a dynamic expansion of photovoltaics (higher % of RES in spring and summer) is visible since 2020. 

• Wind farms generated 13.7% of electricity (2.1 TWh, or 61.2% of RES production), photovoltaics accounted for 2.6% (0.4 TWh – 11.7% of RES), 1.1% came from hydroelectric power plants (0.2 TWh – 4.9% of RES), and 5% from biomass (0.8 TWh – 22.3% of RES).
• The remaining 77.6% of electricity came from fossil fuels: 39.2% from hard coal (6.1 TWh), 17.7% from lignite (2.8 TWh), natural gas 18.8% (2.9 TWh), and other fossil fuels 2% (0.3 TWh).

In the graph we see the percentage shares of electricity production by source. 

• Coal prices for the power industry (PSCMI1 index) rose by 7.2% over the month, to PLN 15.3/GJ (approx. PLN 336/t). Coal for heating plants (PSCMI2 index) costs PLN 18.5/GJ (approx. PLN 422/t), which represents a 1.3% decrease compared to the previous month.
• The weighted average price of natural gas supplied in December fell by 0.4% compared to November, to PLN 172.2/MWh, i.e. 19.4% less than a year earlier.

The chart shows coal, gas prices on Polish and international markets, converted to a common unit (PL/MWh of energy in fuel) for comparability.  
*For coal, the domestic market is represented by the PSCMI1 index and the international market by the ARGUS-McCloskey CIF ARA API 2 index.  
*Natural gas in the domestic market is the weighted average (from POLPX data) delivery price for the month, while the international market for pipeline gas is represented by the TTF exchange index and for LNG by the Henry Hub index. 
For completeness, the chart also shows the price of CO₂ emission allowances from the primary market (trading on EEX). 

• Emissions from the electricity sector amounted to an estimated 8.8 million tonnes of CO2, i.e. 4.5% less than a year earlier and 3.8% more than in November 2025.

Knowing the structure of electricity generation allows carbon dioxide emissions from electricity generation to be calculated. CO₂ emissions are calculated on the basis of reference fuel benchmarks adopted by the Energy Forum and calibrated to the reported emissions of the previous year. 

• Uniform delivery at every hour of the day next year (in the so-called strip – BASE instrument) was traded 2.8% higher, at an average of PLN 463/MWh, and during peak hours (PEAK5) 12% higher, at PLN 569.1/MWh. The valuation of supplies on the SPOT market (RDN) fell by 7.9% to PLN 495.4/MWh.
• The weighted average price of CO2 emission allowances (EUA) on the primary market was EUR 82.7/tCO2, i.e. 2.6% more than a month earlier. In December, PLN 0.8 billion was transferred to the Polish budget as a result of the sale of CO2 emission allowances on the primary market (EEX exchange), and PLN 16.3 billion has been transferred since the beginning of the year.

The graph shows a comparison of the weighted average monthly prices on the POLPX. The Commodity Forward Market covers approximately 80% of the energy sales volume on the Polish Power Exchange.  
The two most important instruments relate to the delivery of energy around the clock (BASE) and from 7 a.m. to 10 p.m. (PEAK5). The contracts are concluded with delivery in the future (max. 3 years). The vast majority of transactions on the exchange are for the purchase of energy with delivery in the coming calendar year (n+1). 
On the basis of the contracts concluded in a given month, the volume-weighted average BASE_n+1 and PEAK5_n+1 indexes were calculated. This reflects the long-term situation on the electricity market. 
In contrast, the TGeBase Index relates to the Day-Ahead Market (with next-day delivery) - it reflects the current market situation and is characterised by high volatility. The weighted monthly average is usually lower than the prices in the Forward Market and seasonal dependencies are negligible.

• CDS (Clean Dark Spread), which is an indicator of the margin of coal-fired power plants, amounted to PLN 4.6/MWh in December, representing 1% of the weighted average wholesale price of electricity supplied in that month. During the year, this indicator fell by approximately PLN 92.7/MWh (it was PLN 97.3/MWh at that time).

The graph shows the Clean Dark Spread calculated from: historical contracts (BASE, PEAK, OFFPEAK) weighted by the share of deliveries in a given month (POLPX Commodity Futures Market), spot market contracts (POLPX Day-Ahead Market), coal prices (PSCMI1) and CO₂ emission allowance prices (EEX primary market).  
The Clean Dark Spread (coal-fired power plant variable cost spread indicator) is the difference between the electricity price and the estimated variable costs associated with coal-fired power generation (fuel and emission allowances). The Clean Dark Spread is an indicator correlated with the profit of the generator, producing electricity from coal (in reality, it is still necessary to take into account transport costs, operating costs, incurred and planned investment costs, etc.). The analysis of the evolution of this value, together with the CSS, allows the estimation of the current financial situation of the generating companies.  
The beginning of the bands corresponding to fuel or entitlements under the horizontal axis is due to the negative value of the CDS. 

• CSS (Clean Spark Spread), which is the equivalent of CDS for gas-fired power plants, amounted to PLN 55.9/MWh this month. In December 2024, it was higher by approx. PLN 41.6/MWh (PLN 97.5/MWh at that time).

The graph shows the Clean Spark Spread calculated based on: historical contracts (BASE, PEAK, OFFPEAK) weighted by the share of deliveries in a given month (POLPX Commodity Forward Market), spot market contracts (POLPX Day-Ahead Market), natural gas prices (POLPX Commodity Forward Market) and CO₂ emission allowance prices (EEX primary market).  
Clean Spark Spread (gas power plants' variable cost spread indicator) is the difference between the price of electricity and the estimated variable costs associated with the production of electricity from natural gas (fuel and emission allowances). Clean Spark Spread is an indicator correlated with the profit of the generator producing electricity from natural gas (in reality, it is still necessary to take into account transport costs, operating costs, incurred and planned investment costs, etc.). The analysis of the evolution of this value, together with the CDS, makes it possible to estimate the current financial situation of generation companies.  
The beginning of the bands corresponding to fuel or entitlements under the horizontal axis is due to the negative value of the CSS. 

• The weighted average price of electricity supplied in a given month consists of: forward contracts concluded in the past and spot market transactions (RDN and RDB). On the spot market, the price of electricity was PLN 495.4/MWh, raising the average price of electricity supplied to PLN 466.2/MWh. If electricity had been supplied solely on the basis of forward contracts concluded last year, this value would have been PLN 450.6/MWh.

The chart shows the price profiles of electricity traded in three ways: 
*RTT - Commodity Futures Market, where electricity is traded in contracts executed at a contracted future, in weekly, monthly, quarterly and annual contracts; 
*RDN+RDB spot market (Day-Ahead Market and Intraday Market), where electricity is traded for delivery today or tomorrow; 
*OTC (Over-the-Counter) - over-the-counter (OTC) trading, mostly contracts concluded within energy groups. 
The price of electricity delivered in a given month is the average of these three prices, weighted by the volumes of electricity delivered at that price (shown in the chart below). 

• There is a correlation between the share of renewable energy sources in electricity production and the price of electricity on the spot market. The highest weighted average hourly price of energy on the RDN market was PLN 1,445.7/MWh, with a 12.9% share of renewable energy sources. In turn, the lowest electricity price (PLN 136.4/MWh) occurred at a time when the share of RES was 41.5%. In addition, most hours with a high share of RES are characterised by a price below the weighted average.
  
  

The first chart shows the distribution of volume-weighted average prices on the Day-Ahead Market and the share of renewables (RES) on individual days of the month. As the share of RES increases, electricity prices tend to decrease.

In the second chart, each point represents a single day of the month, and the slope of the trend line illustrates the relationship between electricity prices and the share of RES in electricity generation.

• On the Polish Power Exchange, trading (the total volume of futures contracts concluded) amounted to 7.6 TWh, which is 26.3% more than a year ago (6.1 TWh). This is still 38.3% less than the average for December in 2018-22, which is 12.4 TWh.
  
  

Knowing the structure of the origin of the delivered volumes makes it possible to determine what proportion of the weighted average price is the result of trading on spot markets, where there is a clear correlation between the structure of the hourly electricity production mix and the price (the greater the production of photovoltaic installations and wind farms, the lower the price). Contracts traded on forward markets, where it is the physical delivery of electricity that takes place many months in advance, allow the risk of future price changes to be priced in. 

• The balance of costs for imports of coal, oil, gas and fuels for June (latest data) amounted to PLN 6.2 billion. Over the previous 12 months, we paid a total of over PLN 103 billion for net imports. It should be noted that since the embargo on LPG imports from Russia was introduced at the end of 2024, imports from this direction were expected to fall to zero. However, there was a noticeable jump in imports of hydrocarbons from this direction, which can be used for fuel production. By July 2025, these costs amounted to approximately PLN 401.4 million. According to the 19th package of sanctions, this gap should be closed by the end of January 2026.
  
  

The graph shows the nominal (excluding inflation) monthly cost of imports of energy raw materials and fuels into Poland. This is a net import, i.e. it also includes exports from Poland of these products. 
*The coal category includes: anthracite, lignite, hard coal (thermal and coking coal) and hard and lignite briquettes. 
*The oil category includes crude oil and natural gas condensates. 
*Gas includes both pipeline gas and LNG. 
*Under the fuel category are motor petrol, diesel, LPG (fuel, not reagent) and various types of aviation fuel.