Geothermal Energy: Bulgaria Has the Resource and the Need. Will We Take Advantage of It?
- 5 days ago
- 6 min read
Updated: 4 hours ago
Georgi Stefanov – Member of the Board of Directors of the Bulgarian Geothermal Energy Association (BAGE)
In times of volatile energy markets, domestic resources can provide competitive prices and strategic autonomy
Georgi Stefanov is an expert in climate policy, energy policy and the green economy with more than 20 years of experience in the transition toward a low-carbon economy. He led the Climate and Energy Programme of WWF Bulgaria (2008–2021) and served as Chief of Staff to the Deputy Prime Minister for Climate Policies (2022–2023). He actively contributes to European climate policy development, including the European Green Deal and industrial decarbonisation. He is a member of the Board of Directors of the Bulgarian Geothermal Energy Association (BAGE) and teaches at New Bulgarian University and Sofia University “St. Kliment Ohridski”.
Geothermal energy is already economically competitive — its costs are comparable to those of coal and gas power plants.
The potential of this technology in the European Union is significant: more than 300 TWh of annual electricity generation, which is approximately 42% of the current output from coal and gas.
Unlike variable renewable sources, geothermal energy provides continuous baseload power and contributes to the stability of the electricity system. This makes it a resource of systemic importance.
The question is no longer whether the technology works, but how it will be positioned within the energy mix.
Bulgaria has favourable geological conditions that allow competitive and predictable energy prices.
To transform this potential into real economic impact, the country must make a strategic choice — to place geothermal energy among the priorities of its national energy policy.
Geothermal energy can already provide competitive electricity at a scale capable of covering a significant share of Europe’s needs, comparable to coal-fired power plants.
This is highlighted in the latest report by the energy think-tank Ember, published in February 2026, “Hot Stuff: Geothermal Energy in Europe.”
The question today is no longer whether the technology works, but how it will be positioned within the energy mix of Europe and Bulgaria.
What are the benefits of geothermal energy?
Geothermal energy is the only renewable technology capable of generating electricity continuously, helping the grid maintain stable frequency and reliable operation. For this reason, it effectively provides baseload generation.
Geothermal energy does not require the import of fossil fuels and is not exposed to international price shocks.
In the context of increasing military conflicts and tensions along global energy supply routes — which directly affect gas, oil and electricity prices — the development of domestic energy resources becomes an element of national security. Geothermal energy can contribute precisely to such greater energy autonomy.
Geothermal energy is also not exposed to the price of carbon emissions, giving it an advantage over coal and gas power plants and ensuring greater price predictability both in the short and long term.
In addition, a significant part of the technological value chain is produced in Europe — from drilling services to engineering solutions — creating domestic industrial value and reducing dependence on imported energy technologies and solutions.
This combination of price resilience, regulatory stability and the ability to provide constant baseload generationdistinguishes geothermal energy from other renewable sources. It should therefore be viewed not merely as a complementary technology, but as a resource of systemic importance.
What do the latest data for Europe show?
After examining the technological characteristics of geothermal energy, it is important to look at the real picture in Europe today — in terms of capacity, production and projects.
A large potential
At generation costs below €100 per megawatt-hour (MWh) — comparable to coal and gas power plants — geothermal energy could provide around 50 gigawatts (GW) of capacity in Europe. Of this, approximately 43 GW could realistically be deployed within EU member states. Because geothermal plants can operate almost continuously — with capacity factors between 75% and 95% — they have the potential to produce more than 300 terawatt-hours (TWh) of electricity annually. In other words, this is enough electricity to supply tens of millions of European households, or close to half (42%) of the electricity generated by coal and gas power plants in the EU in 2025.
Geothermal energy therefore already has a potential comparable to a significant share of traditional fossil-fuel baseload generation.
More and more European countries are developing geothermal projects
Today, 147 geothermal power plants operate in Europe, producing around 20 TWh of electricity annually.Production remains concentrated mainly in Turkey, Italy and Iceland, but the sector is gradually expanding.
Geothermal electricity is now also produced in Croatia, France, Germany, Hungary, Austria and Portugal, while new projects are being developed in Belgium, Slovakia and neighbouring Greece.
At the same time, around 50 geothermal power plants are currently under construction or in various stages of planning, indicating a clear trend of sector expansion. This is also contributing to declining investment costs per kilowatt of installed capacity.
Although this trend is not explicitly highlighted in the Ember report, it is clearly observed in the market for new geothermal projects. Companies developing such facilities over the past two to three years confirm this development.
At the same time, analyses show significant geothermal potential, particularly in Central and Eastern Europe.The largest economically competitive potential (below €100/MWh) has been identified in Hungary, with about 28 GW, followed by Turkey with nearly 6 GW.
Countries that have developed this energy segment over the past decade have already demonstrated its substantial potential. In many other countries, the process of exploration and confirmation is currently underway — including Bulgaria.
This means that countries with traditionally coal-based energy systems and strong industrial traditions have a real opportunity to gradually replace part of this baseload generation with domestic geothermal resources.
Fig. 1: Installed geothermal capacity by country (MW), including operating and under-construction plants / Source: EMBER based on data from EGEC’s Market Report, 2024
Technological breakthroughs are expanding geothermal potential
This potential is not accidental. Advances in drilling technologies and geothermal reservoir management now allow economically efficient energy production beyond traditional high-temperature zones. This expands the geographical reach of the technology and makes it applicable in a larger number of countries.
At the same time, a significant share of the production and supply chain — from drilling services to the construction of power plants — is developing within Europe. As a result, geothermal energy is gradually becoming not only an energy resource but also a structural element of European industrial policy.
The “European Strategy and Action Plan on Geothermal Energy – for a competitive, secure and affordable Europe,” expected to be presented on 19 May, is likely to further reinforce this direction.
Bulgaria’s geothermal opportunity
Within this European context, the natural question arises: what is the potential of Bulgaria?
Bulgaria has real geological potential
Bulgaria has a genuine geological potential for the development of geothermal energy.
The country possesses a substantial body of accumulated geological data indicating favourable temperature conditions at accessible drilling depths. This means that the resource is not hypothetical but technically accessible.
According to expert assessments by the Bulgarian Association Geothermal Energy (BAGE), given the available potential, the cost of geothermal electricity in Bulgaria could be lower than the EU average.
With the current marginal costs of coal and gas power plants ranging between €90 and €150/MWh, geothermal energy is no longer merely an “alternative,” but an economically sound baseload energy solution with a predictable price profile.
This has direct implications for the country. As coal regions undergo transformation, Bulgaria needs domestic low-carbon baseload capacity capable of ensuring system stability and competitive electricity prices. Geothermal energy can fulfil precisely this role.
The question is no longer technological — it is strategic.
Bulgaria can choose to include geothermal energy as a priority within its national energy strategy. This would represent more than simple diversification of energy sources.
It would strengthen industrial competitiveness, provide more predictable electricity prices, attract new investments, and reduce dependence on coal and gas — both for electricity generation and for the modernisation and decarbonisation of district heating systems.
The Ember report shows that the window for such positioning is already open. The remaining task is for Bulgaria to prioritise this issue.
In a context of unstable international energy markets, such a step also has a national security dimension, while the new EU financial instruments planned for the 2028–2034 period will very likely be directed precisely toward such strategic investments.
END
