Bulgaria’s current energy mix

The Bulgarian electricity market is currently in transition, but nuclear power is expected to remain dominant. The government is slowly decreasing its coal power capacity to gradually replace it with renewable power capacity. During this energy shift, the government plans to rely on nuclear power generation to meet the major electricity demand.

Nuclear power generation was 15.9TWh in 2020 making its share 44% in total power generation in the country. Nuclear energy will remain a dominant source for power generation until 2030, despite plans to increase renewable power capacity. Bulgaria currently has 12,668MW of installed capacity, enabling the country to meet and exceed domestic demand.

Lignite coal is mainly behind the growth of electricity production. Data for 2021 show an increase in electricity production from this local coal by 30.8%, reaching 18,888GWh. Thus, nuclear energy, which in 2020 had the largest share in the electricity mix, has been displaced from the first place. Nevertheless, nuclear power production remains higher than in 2019 and 2020 at 16,487GWh (a 0.1% increase when compared to 2020).

The production of electricity from natural gas, like lignite, also marked a significant jump of 27.7% compared to 2020, reaching 2,788 GWh. The past year also turned out to be extremely favorable for the hydropower production, which realized an increase of 52.5% and 5,095GWh were produced. However, it should be noted that the electricity generated by hydropower pumping capacity has fallen almost twice from 447GWh (2020) to 222GWh (2021).

The production of electricity from other renewable sources turned out to be more modest compared to 2020. In 2021, the amount of electricity produced by solar power exceeds that of wind. The corresponding values ​​are 1,428GWh (a 0.1% decrease when compared to 2020) and 1,388GWh (a 2.7% decrease when compared to 2020). Biomass electricity decreased by 1.2% to 249GWh.

Environmentally friendly, efficient and secure energy is critical to Bulgaria’s productivity, competitiveness and growth. Bulgaria is a major producer and exporter of electricity in the region and plays an important role in the energy balance of the Balkans. The country’s strategic geographical location makes it a major hub for transit and distribution of oil and gas from Russia to Western Europe and other Balkan states.

The future of the Bulgarian nuclear market and project opportunities

Bulgaria has a long-standing positive experience of nuclear energy, recognizing the benefits it brings to people and the environment. Bulgaria currently has 2 nuclear reactors, generating about one-third of its electricity.

In 2020, the country had only 1 nuclear power station known as the Kozloduy nuclear power plant (NPP) which has 6 units. After the decommission of Units 1 and 2 Kozloduy NPP in 2002, and Units 3 and 4 in 2006, all the nuclear power is generated through Units 5 and 6.

In line with the National Recovery and Resilience Plan, the Bulgarian government announced plans for creating energy storage capacity for 6GWh by 2026 and a new battery plant is planned near Stara Zagora. The project includes the implementation of smart grids to reduce technological losses in the network and improve transparency, accuracy, and rapid response to accidents. The idea with batteries is to divert electricity exports toward Bulgarian businesses.

The leadership of the state is currently negotiating with the United States on nuclear power technology for Kozloduy, as well as options for supply of United States liquefied natural gas (LNG) and CO2 capture systems.

Bulgaria has taken multiple steps toward the development of nuclear power in the country in recent times; the country even joined the Nuclear Energy Agency (NEA) in January 2021. Moreover, Kozloduy NPP also signed a Memorandum of Understanding (MoU) with United States-based NuScale Power for the deployment of NuScale’s small modular reactor (SMR) technology. Such steps provide a clear indication that the government, despite plans to shift toward renewable power, is still keen on developing nuclear power.

Nuclear project opportunities exist in the following areas: 

  • Equipment of the Turbine Hall of the new nuclear capacity, including switchgears, transformers and other power evacuation;
  • Maintenance and upgrade of steam turbines at Kozloduy NPP;
  • Activities related to the decommissioning of four NPP reactors;
  • Small /Advance Modular Reactors;
  • Diversification  of Kozloduy NPP’s fuel supply;
  • Removing and packaging of historical nuclear waste;
  • Nuclear safety and radiation protection;
  • Technical support for the regulatory body; and 
  • Working with Bulgaria’s universities on training and educating nuclear engineers.

In May 2022, the 20 unions representing Belgian, Bulgarian, Czech, Finnish, French, Hungarian, Lithuanian, Romanian, Slovakian and Slovenian energy workers stated the inclusion of nuclear and gas in the European Union taxonomy is vital for tackling climate change and increasing energy independence.

Bulgaria’s opportunity to shift to renewable energy sources

The Russia-Ukraine-NATO crisis created an opportunity for Bulgaria to expand renewable energies and invest in energy efficiency solutions, rather than merely replace one gas supplier with another.

Currently, Bulgaria has the goal of using 27% of renewable energy sources (RES) by 2030. However, the planned investments in the renewable energy sector are currently insufficient for the transformation of the energy mix. Some experts argue that Bulgaria should shift its focus away from large-scale energy projects and towards the decentralization of electricity production with a leading role and thought for households and small and medium enterprises.

Currently, the focus is on financing large-scale projects for RES investment tenders, under which a minimum quota of 25% is set for the installation of battery storage systems. This project to connect 1.7GW of RES capacity puts excessive focus on the use of batteries. This means that in the framework of well-interconnected power markets in the Southeast Europe (SEE) region, the excess power storage capacity does not make much economic sense.

The transformation of the electricity mix on the part of RES and Kozloduy nuclear power plant should put an end to rising electricity prices, and volatility may occur at limited times of the year, when a combination of imports, demand management systems and energy efficiency, would smooth out the peaks and ensure security of supply.

Promoting renewable energy

Bulgaria started renewable energy promotion, including the establishment and implementation of the institutional and legal framework only in 2007. The state experienced strong RES development in two periods (2007-2012 and 2012-2016) and increased its share dramatically. Bulgaria will increase the installed capacity for renewable energy from 1.8GW to 4.3GW by 2024.

By the end of 2030, Bulgaria is targeting a further 2,645MW (2,174MW in solar, 249MW in wind, 222MW in biomass) of electricity generation capacity installed from RES, mostly photovoltaic plants, in line with the European Union goals for green energy transition. In accordance with Bulgaria’s Electricity System Operator’s (ESO) plan, by 2030 the share of the energy produced by RES in Bulgaria’s gross final consumption should reach 27.1% where the European Union target is 32%.

In Bulgaria, there are 242 hydropower plants in operation. In total, the National Electric Company (NEK) owns 30 conventional hydro and pumped storage plants with a total installed capacity of 2,713MW in generating mode and 937MW in pumping mode. Hydropower’s importance is not limited to the production of energy because it plays a key role in greenhouse gas emissions reduction.

Hydropower contributes to an annual avoidance of 491,690 tons of CO2 emissions, which translates into an annual CO2 cost savings of USD $3.5 million. Another significant benefit of the sector is the opportunity for integrated water resource management to reduce the risk of natural disasters. Bulgaria must take urgent control measures on small hydropower to avoid European Union sanctions; in other words, the local authorities need to take urgent measures to effectively control small hydroelectric power plants.

By the end of 2024, ESO will finalize its investment program  aiming to secure the grid connection of new power plants with a total installed capacity of 4,500MW, primarily renewables.

ESO has invested more than EUR 25 million in the digitalization of the grid; modernization and digitalization of the medium-voltage grid is expected to be completed by 2024. The deadline was mid-2026, but activities were implemented much faster.

ESO has also signed preliminary agreements for 4,000MW, and it must secure the connection for 4,500MW, according to the target set in the country’s National Recovery and Resilience Plan. The plan also sets a goal to increase the cross-border transmission capacity by 2,000MW. 

Regional cooperation

Bulgaria has already finished its part of the new power line with Greece, where neighbouring Greece needs to build the remaining 29 kilometres of the new interconnector with a total length of 122 kilometres. By the end of 2023 it is expected the power line will become operational.

Also, Greece and Bulgaria have recently signed an MoU on natural gas storage and a new oil pipeline, announcing the documents will deepen the 2 countries’ cooperation in the energy sector and benefit the wider region. The first MoU aims to allow energy companies from Greece to store natural gas in Bulgaria’s Chiren depot, while Bulgarian companies would be able to use the LNG terminal at Revithoussa near Athens. Under the second MoU, the 2 sides will explore possibilities for reviving a project to build an oil pipeline between the ports of Alexandroupolis in Greece and Burgas in Bulgaria.

Furthermore, 2 shared hydropower plants were announced in January 2023 by Bulgaria and Romania, modeled after the successful Iron Gates plants Romania already operates together with Serbia. Bulgaria’s Minister of Energy, Rosen Hristov, confirmed that the plants are part of Bulgaria’s strategy for the energy sector until 2053 and will be built by the Romanian state company Hidroelectrica.

About the Author: Felipe Gaitán Michelsen