The further large-scale penetration of renewable energy sources (RES) in Europe into the EU's energy systems goes through the development of nuclear power plants. For the production of green hydrogen in the region, the only option is nuclear power plants. This was commented by the executive director of the Electricity System Operator (ESO) Angelin Tsachev within the framework of the International Nuclear Conference "Bulgarian Atomic Energy - National, Regional and Global Energy Security", which is being held in the Rivera complex near Varna.
At this moment, the country's grid is extremely well and balanced, given the good planning and development of conventional generating capacities. Of course, with the greater penetration of renewable energy sources into the energy mix, this balance in the network is beginning to be disturbed and requires serious investments in its development in order to preserve its adequacy and the security of supplies to all consumers in the territory of the country, explained Tsachev. He presented the ESO's vision for the country's future electricity mix by 2050 in terms of carbon neutrality and regarding the place of large reactors in the energy system. ESO operates the entire electrical transmission system of Bulgaria, covering 16,000 km of 110, 220 and 400 kilovolt power lines and over 300 substations, of which over 32 are system - 400/110 kilovolt.
According to the executive director of ESO, over 13 thousand MW of generating capacity were operating in the country last year, 34% of which were from coal plants, 15% from the two units at the Kozloduy NPP, gas plants - approximately 10% (mainly steam and gas, connected with the heating of the cities, plus the Varna thermal power plant) approximately 24% from hydroelectric power plants and PAVEC, nearly 12% photovoltaic plants, 5% - wind. According to him, by the middle of this year, the intensive introduction of photovoltaic plants is already approaching their participation to 15%.
"Electricity production (in 2022) is a record for our country - over 50 TWh. The export is a record - more than 12 million kWh of electricity, realized in the region of South-Eastern Europe", said the executive director of ESO. He specified that this is mainly due to the TPPs in the Marishski Basin, as well as the traditional production of between 32-35% from the Kozloduy NPP.
When presenting the ESO's vision of what the energy mix should be by 2050 in order to achieve complete decarbonization, as well as considering the growing consumption in the country, Tsachev emphasized the need to "maintain the adequacy of the system, which is currently 99.996% which means that no more than 4 hours of problem with capacities in the country, as well as to guarantee the security of supplies".
"Our vision is that 55% of the electricity in order to fully decarbonize the country should be from base nuclear power," he explained, emphasizing the need for flexibility over a wide range to participate in regulating the system.
The expectation is that 22% of the energy mix will be from the sun, 14% from wind and 5% from hydropower, given the limited water resources of our country. In doing so, the role of hydropower plants will be directed towards peak consumption, but also when they should be able to be used as base capacities as well.
"When presenting the energy vision in January, many scenarios were made regarding the energy mix in the country and the entire region, since we are already a common market and we should not consider our country as a closed system. In our opinion, it is most correct to evaluate all the views of the entire region, to evaluate the possibilities of the individual member states, in order to prepare the best scenario for the development of electric power capacities," Tsachev said.
He also settled on the most conservative possible scenario, regarding the decommissioning of coal-fired power plants by 2035. In this scenario, a very serious shortage of electrical energy of 40-45 TWh is emerging in the entire region of Southeast Europe. "Because this problem continues to deepen and the only solution is the construction and commissioning of new nuclear facilities to satisfy consumption in the SEE region," Tsachev pointed out. Previously, within the framework of the conference, similar expectations were shared by the ambassador of Slovenia, as well as other participants. The scenario is based on a study commissioned by ESO and is based on information from the countries of the region.
On this basis, "in 2035 - 2040, the amount of energy produced by nuclear plants in the SEE region should reach 100 TWh to satisfy the consumption in the region. Otherwise, it will be highly deficient, which implies that there will have to be higher electricity prices and lower investments in other economic sectors," said the executive director of the ESO.
In this regard, he also outlined the importance of nuclear power in two aspects - the first aspect concerning ensuring security of supply. "NPPs are the only large-scale energy source that can meet demand 24 hours a day, 365 days a year, and most importantly, produce almost emission-free energy, helping Europe's fight against climate change. Per 1 MW of energy produced, the CO2 intensity is approximately 11 kg, while from a solar plant it is between 50 and 70 kg, and a wind plant between 90 and 130 kg. This is an extremely important part of our fight against climate change," Tsachev pointed out.
The second aspect, according to him, considering the entry of many RES in the region, is extremely important the change of power of the blocks, which should happen within 15 minutes to balance the countries' power systems.
ESO has developed a scenario for the construction of 2,400 MW of nuclear power at the Belene NPP site and 2,400 MW at the Kozloduy NPP site. When developing the scenarios, the system operator has taken into account that the development of the network guarantees the security of the network. From this point of view, Tsachev explained that the difference in the development of the network between Kozloduy NPP and Belene NPP is one transmission line of 100 kilometers. In his words, against the background of the entire investment, "this is simply insignificant", and later he explained to journalists that it is an investment of BGN 70 million, which is being undertaken by the company building the Belene NPP.
"The other significance of nuclear units from a systemic point of view, given the serious penetration of RES in the energy mix of the country and the entire region, is related to the momentum of the system. The dynamic stability in the power systems is violated because there is no momentum, which is provided at this moment by the large electric generators," explained Tsachev. According to him, with the introduction of RES, which do not have such momentum, the problems are starting to become more and more tangible.
“Why I say these things need to be addressed is because solar and wind power cannot provide that kind of momentum. There is some momentum in modern inventors, but they cannot completely replace the momentum created by large energy generators. Therefore, from an energy point of view, a balance must be found, to have dynamically sustainable systems", which, in his words, on the other hand, are carbon neutral.
The further development of renewable energy sources and their large-scale entry into the energy systems of the EU go through the development of nuclear power plants. Given the entry of the further carrier in the form of green hydrogen, according to ESA, the only option for green hydrogen production in our region is through renewable energy sources and nuclear plants.