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Operation of the Czech Republic's power system

The current operation of the Czech Republic power system is relatively comfortable, due to the significant share of well-regulating brown coal fired sources and a significant share of the nuclear energy as a source of baseload supply. The utilisation of hydro pumped storage power plants has increased in recent years. Gas fired sources still have a complementary role and renewable sources are already an integral part of the Czech power system. In the future, the situation will change significantly: coal units will be decommissioned due to many reasons, the Dukovany nuclear power plant has already exceeded its originally projected lifespan and, on the contrary, an increasing share of renewables can be expected. For their successful integration, flexibility will have to be utilized even where it has not been acquired yet - even on consumption side, and among other things new quick start natural gas units, daily and seasonal accumulation. No-emission district heat supply has only one solution - heat supply from nuclear power plants.


Medium-term horizon

Reliability of the power balance meets the reliability standard with sufficient reserve. By the end of the medium-term horizon, differences between winter and summer balances of generation adequacy start to show, which is mainly given by different trends in consumption growth and by the share of RES.

Supplies from brown coal dominate until 2020. In around 2020, several brown-coal power plants are likely to be decommissioned. After that, availability of brown coal will stop being a considerable limiting factor for the remaining power plants. In compliance with that, high utilization of available capacity of thermal solid fuels fired system power plants is anticipated. In around 2020, increasing trend of the utilization can be seen in the group of gas fired system power plants, which is supported by the increase in allowance price. The increase is higher in the EU case studies. The utilization is therefore higher too and reflects in high total supplies of electricity from gas. Operation of nuclear power plants is stable; in general, they work close to a 100% utilization.

The case studies generally differ in the domestic net consumption increase trend, which in the upshot reflects in the development of (mostly export) balance of cross-border electricity trading. In the EU – Energy Savings case study, the domestic net consumption is the lowest while the export balance is the highest. Medium course of both the domestic net consumption and the export is considered in the Conceptual case study; the highest domestic net consumption is in the EU – Low-Emission Sources case study. Electricity export is supported by the higher anticipated development of RES. In the Zero case study, the domestic net consumption is identical to the Conceptual case study but due to the zero development of sources (mainly of the distributed character), the export is the lowest. In 2030, total balance shows import character.

Electricity supplies according to primary energy sources – Conceptual case study

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Long-term horizon

The summer and winter balances of generation adequacy further deepen as well as the differences between the case studies. The generation sufficiency balance shows the need of imports in maximum loads at the average level of 2-4% of electricity supplies. However, in the overall summary per year, no considerable emergencies appear and if suitable measures are adopted, the system meets the reliability standard until the end of the analysed time horizon.

Beginning with 2031, the Zero case study would require great import of electricity annually and the values are growing steadily. In the three development case studies, the import balance is accepted but only temporarily and in low annual volumes. Otherwise, it is compensated by targeted development of sources.

Initial positions of the development case studies differ in 2031. In this year, all case studies consider decommissioning of 730MW of the existing large sources. Due to the lower domestic net consumption, export balance of ca. 6TWh is identified in the EU – Energy Savings case study. In the Conceptual case study, the export is negligible. In the EU – Low-Emission Sources case study as well but due to the high domestic net consumption and under other presumptions, such as high solar and wind power plants development, are fulfilled. The rather stabilized state of the Czech power system lasts till 2036.

By 2036, electricity supplies from RES are higher in the EU – Low-Emission Sources case study than in the other case studies. Electricity supplies from natural gas are higher in both EU case studies than in the Conceptual case study. The utilization of available capacity of selected gas fired sources is also considerably higher, which relates to the anticipated higher allowance price. On the contrary, electricity supplies from coal and utilization of the respective sources is slightly lower. Supplies from nuclear sources continue in similar volumes in all three case studies with the utilization factor of 98-99%.

Between 2036 and 2044, the existing brown-coal units are gradually decommissioned in all three case studies as a consequence of termination of a great part of brown coal sources and as electricity production from this fuel decrease. Compensations of this outage are partly identical but often differentiated in the case studies. In the EU – Energy Savings case study, the potential to decrease the remaining electricity export is exhausted by 2038. In the Conceptual case study, utilization of natural gas fired sources increases at the same time to the level of the EU case studies. In 2039, an increase in electricity supplies from the first 1,200MW unit in Dukovany is anticipated in all case studies. Installed capacity of natural gas fired sources increases in all three case studies (until 2044). In the Conceptual case study, several sources supplying both electricity and heat are included – electricity production from gas is high, culminate in 2042 and in some years they even return the system its export capability. In the EU case studies, these sources are often intended as idling regulation reserves – electricity supplies culminate more or less in the same year but with much lower values. Natural gas acts more as a reserve, which is also reflected in gradual decrease in the utilization, though the allowance price keeps increasing – higher generation would imply higher CO2 emissions.

In course of the above seven year period, total utilization factor of nuclear energy decreases ending up with values ranging from 95% to 99%. Nuclear electricity supplies on the other hand increase; they are supported by implementation of 2x 1,200MW units replacing of the 4x 510MW units and are dominant in all case studies. In the EU – Energy Savings case study, the supplies from RES increase similarly.

Electricity supplies according to primary energy sources – EU – Energy Savings case study

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In 2045, the Počerady CCGT is not in operation. Beginning with this year, electricity production from gas is lower in all case studies up until 2050. One nuclear unit of 1,200 MW is included in all case studies in 2045. Nuclear electricity production is thus further strengthened. In consequence of both these changes in installed capacity, electricity production from coal decrease in all case studies as well as the utilization of the respective sources.

In the Conceptual case study, electricity production and its structure is more or less stabilized by 2050 with only moderate increase in RES. In the EU – Energy Savings case study, electricity production is similarly stabilized by 2050 but the increase in RES is slightly higher. This presumption however does not apply to electricity production from coal which decrease down to zero to fulfil the targets of Roadmap 2050. Within the decrease, a great part is caused by decommissioning of the 660MW unit in Ledvice at the turn of 2045 and 2046. The number of natural gas sources increases; with respect to CO2 production, they are again run as idling reserves and the utilization therefore decreases in the whole group. Electricity production from synthetic methane increase but remain low in comparison to other sources.

The same description applies to the EU – Low-Emission Sources case study in which however, due to the higher domestic net consumption, higher need for electricity supplies from low-emission sources is identified. These sources are the fast growing RES on the one hand and the nuclear sources, strengthened in 2047 by the fifth 1,200MW unit, on the other hand. A one year earlier commissioning is probably not implementable, which is why electricity import in the volume of 6.8 TWh is considered in 2046. Compared to the previous case study, electricity production from synthetic methane are higher.

In both EU case studies, use of heat from nuclear blocks is anticipated. Those units then, in consequence, cannot achieve their full electric capacity especially in winter months. Values of their utilization in last years of the period range between 90% and 96% in all three case studies. The share of nuclear electricity is as follows:

  • in the Conceptual case study, it slightly exceeds 50%,
  • in the EU – Energy Savings case study it amounts to 56%,
  • in the EU – Low-Emission Sources case study it, despite higher supplies, amounts to 48%.


In 2050, the share of RES in electricity production in the Conceptual case study amounts to 23%, in the EU – Energy Savings case study to 29% and in the EU – Low-Emission Sources case study to 41%.

With the exception of the Zero case study which is not operable in the long term, operability of the Czech Republic's power system is ensured in all case studies. It will require number of measures: apart from the above mentioned construction of regulation sources, for example facilities for synthetic methane production (P2G), i.e. seasonal accumulation, and daily electricity accumulation facilities. Their development is greatly differentiated among the case studies in the long term and the highest is in the EU – Low-Emission Sources case study. Implementation of these facilities was however only considered after the anticipated flexibility potential of simpler and cheaper ways is applied at the side of both sources and consumption (photovoltaics, small-scale CHP, delayed consumption of households, ripple control, electromobility etc.).

Electricity supplies according to primary energy sources – EU – Low-Emission Sources case study

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