**4. Production, Distribution and Consumption of Electricity in Slovakia**

A power system of 7721 MW was installed in 2017 and the system integrated the production of electricity from almost 2800 electricity production sources, according to the Yearbook 2017 of the SEPS [31]. Electricity consumption reached 31,066 GWh, of which the domestic production was accounted for 28,036 GWh. The electricity production balance reached 3 030 GWh, i.e., almost 10%. The annual power maximum of 4550 MW was reached on January 11, 2017, and the power minimum of 2380 MW on 21 May 2017, the regulatory range of the system was of 2170 MW. The share of production from fossil fuels, nuclear sources, and renewable energy sources (RES), as well as the import of electricity, has been stabilized for the long time, and optimal in terms of safety and reliability. Regulatory requirements increase due to the unpredictable change in the power of photovoltaic power plants, with an installed power potential of 540 MW. When compared to 2015, the installed capacity was reduced by more than 400 MW. Four units of coal power plants were decapitated, of which two 110 MW blocks belonged to the Coal Power Plant Novaky and two blocks of equal power belonged to the Coal Power Plant Vojany. The reason for the decapitation was the failure to comply with the prescribed environmental requirements of the EU and SR. The Ministry of Economy of the Slovak Republic did not allow further decapitation of system resources installed capacity in order to maintain energy security of Slovakia, unless they are put into operation the domestic sources, i.e., new blocks of the nuclear power plant in Mochovce.

Electricity that is produced in the Slovak Republic is loaded with low greenhouse gas emissions. In 2017, only 20% of electricity was produced from fossil fuels. The total load of electricity that was consumed by CO2 emissions was 230 g/kWh, which is the seventh lowest position within the 28 EU countries.

Table 1 shows the share of resources for installed power and total electricity production, costs, and prices of electricity produced and imported. Table 1 provides a detailed overview of the major electricity producers (about 90% of electricity production in Slovakia) with the volume of emitted CO2, NOX, and SOX.


**Table 1.** Production and consumption of electricity in Slovakia in 2017 (Source: [31,32]).

Among the "other RES" belongs, e.g., geothermal energy or sewage sludge processing in Slovakia. The price of electricity from photovoltaics is several times higher than from coal due to the high investment and costs and lower efficiency of utilization of this RES. For solar energy, the average use of installed power is only 13.1% and for coal 55–60%. Coal from Slovak mines is subsidized by the state, so the price is as high as the price of biomass.

The price of electricity and natural gas is rising, mainly due to the dramatic increase in the price of greenhouse gas emission allowances. Paradoxically, in Slovakia at the end of 2018, an Act was issued to stop the combined production of electricity and heat from biomass. Electricity that is produced in this way is considered to be particularly environmentally friendly in a civilized world, because, in addition to high energy efficiency, it slows down climate change, as it is neutral in terms of greenhouse gas production. Moreover, the prices of heat that is produced in the cogeneration process together with electricity would not increase for more than 400 thousand of the inhabitants of Slovakia, as the purchase of emission allowances does not affect this production.

Figure 1 introduces the end user price of electricity according to the energy sources.

**Figure 1.** Comparison of commodities end user prices (Source: [31,32]).

Figure 2 shows the electricity production and consumption in Slovakia, as well as the electricity production and consumption balance.

**Figure 2.** Production and consumption of electricity in Slovakia (Source: [31,32]).

Figure 2 shows the decrease in electricity production. The reason is the termination of the operation of the first block V-1 of nuclear power plant in Jaslovske Bohunice in January 2007 as well as its second block V-1 in January 2009. Each of these V-1 blocks generated 10% of all energy that is produced in Slovakia. The country is expected to become self-sufficient again after putting the third and fourth block of the nuclear power plant in Mochovce into operation (2019, 2020).

Figures 3–5 show the commodities end user prices for electricity, gas, and EUA's emission allowances.

**Figure 3.** Electricity end user prices development on the stock market—the index PXE (Source: [33]).

**Figure 4.** Stock market year-on-year increase of average electricity end user prices (€/year) in period 2009–2018 (Source: [33]).

**Figure 5.** Gas end user prices on the stock market—the index PXE (Source: [33]).

Figure 3 shows the development of the electricity price on the stock market—the PXE index in the period April 2017–January 2019.

The stock market average electricity end user prices for period 2009–2018 are introduced in Figure 4.

Recently, the price of electricity had been significantly rising, being mainly driven by the course of electricity prices in neighbouring countries, as well as gas price developments and the price of greenhouse gas emission allowances (Figures 5 and 6).

**Figure 6.** End user prices of emission allowances for greenhouse gases (Source: [34]).

Figure 7 shows the course of the spot price of electricity in Slovakia in 2018 according to the Energetika.cz web portal [19].

**Figure 7.** Electricity spot prices in 2018 (Source: [33]).

The rising price trend in 2018 was due to the extraordinary rise in commodity prices on stock markets. The prices that are introduced in Figure 7 reflect the year-on-year increase of prices in the production of electricity by 27%, gas by 24%, and emission allowances increase by more than 200%.

Figure 8 introduces the utilization of the Slovak electrical system and its coverage by the energy sources on 7.12.2018.

**Figure 8.** Slovak electrical system utilization and its coverage by the energy sources on 7.12.2018 (Source: [35]). PSHPS—Pumped-storage hydropower stations.

It can be seen from Figure 7 that, during the selected day, the least dynamic variation in electricity (power) produced was recorded by the nuclear power plants, sources of electricity from biomass and other RES, lignite and hard coal, other fossil fuels, and natural gas. On the other hand, significantly dynamically variable electricity production (power) is evident in the case of hydropower plants, pumped-storage hydropower stations (PSHPS), solar power stations, and import/export. It is also clear

from the figure that, during daylight, when the power of solar power plants increases, hydropower plants and PSHPS simultaneously control this power.
