In the context of accelerating climate change and increasingly stringent environmental policies, carbon intensity has become a key indicator for assessing the environmental performance of energy systems. It is commonly defined as the amount of carbon dioxide (CO₂) emitted per unit of electricity generated, typically expressed in grams of CO₂ per kilowatt–hour (gCO₂/kWh). This metric provides a direct link between the composition of a country’s energy mix and its associated emissions, enabling meaningful comparisons across countries and over time. Lower carbon intensity levels are generally associated with a higher share of low–carbon energy sources, whereas higher values reflect continued reliance on fossil fuels.
At the EU level, trends in carbon intensity are shaped by a comprehensive policy framework aimed at decarbonising the energy system. Key instruments include the EU Emissions Trading System, which establishes a carbon price for electricity generation and energy–intensive industries, thereby incentivising emissions reductions. Complementary regulatory measures, such as the Renewable Energy Directive and the Energy Efficiency Directive, set binding targets for renewable energy deployment and reductions in energy consumption. These policies are embedded within broader strategic frameworks, notably the European Green Deal and the Fit for 55, which collectively outline the EU’s pathway towards climate neutrality by mid–century while allowing Member States flexibility in implementation.
Within this European context, Bulgaria stands out with a mixed but evolving picture. In 2024, the country’s greenhouse gas (GHG) emissions were dominated by CO₂ (73.2%), followed by methane (CH₄) at 15.8%, nitrous oxide (N₂O) at 8.2%, and fluorinated gases at 2.8%1. Given its overwhelming share, CO₂ is the primary driver of Bulgaria’s emissions profile and thus the central focus of decarbonisation efforts. Within this context, the power sector stands out as the largest source of emissions, accounting for approximately 34% in 2024, followed by transport at 30%. However, sectoral trends diverge significantly: while emissions from transport have increased by 14% since 2015, emissions from the power sector have declined substantially – by approximately 58% over the same period. This divergence reflects structural differences in decarbonisation pathways, with electricity generation more directly exposed to EU climate policies and technological substitution.
Carbon intensity in this analysis is calculated by dividing total CO₂ emissions from the power sector (based on data from EDGAR) by total energy generation (reported by ENTSO–E). The results show a significant downward trend: in 2024, Bulgaria’s carbon intensity decreased by 15% compared to the previous year and by 44% relative to 2015 levels. That progress, however, has not been smooth. There are notable fluctuations. In 2017, carbon intensity increased slightly, suggesting temporary reliance on more carbon–intensive generation. A more significant reversal occurred during 2021–2022, when carbon intensity rose by a cumulative 21% compared to 2020. This period coincided with the European energy crisis, when high gas prices and energy security concerns led to increased coal use across many countries, including Bulgaria.
Table 1: CO2 emissions by sector, Bulgaria, 2015-2024
| Sector | % share of total CO2 emissions for 2024 | 2024 vs 2025 |
|---|---|---|
| Agriculture | 2% | |
| Buildings | 3% | |
| Fuel Exploitation | 7% | |
| Industrial Combustion | 11% | |
| Power Industry | 34% | |
| Processes | 12% | |
| Transport | 30% | |
| Waste | 0% |
When placed in a European perspective, Bulgaria’s role appears relatively small in absolute terms but significant in structural terms. In 2024, the country accounts for around 2% of total EU power sector emissions, ranking roughly 15th. Much larger economies such as Germany, Poland, and Italy dominate emissions due to the size of their energy systems. Meanwhile, countries like Sweden, with extensive low–carbon generation, contribute only about 1%.
Despite its relatively smaller share of total emissions, Bulgaria ranks among the most carbon–intensive energy systems in the EU. In 2024, its carbon intensity is estimated at approximately 320 gCO₂/kWh, significantly above the EU’s lowest values observed in countries such as Finland (25 gCO₂/kWh), Spain (31 gCO₂/kWh), and Sweden (36 gCO₂/kWh), as well as its neighbouring country Romania (72 gCO₂/kWh). At the higher end of the spectrum, countries such as Estonia (605 gCO₂/kWh) and Poland (712 gCO₂/kWh) exhibit even greater reliance on carbon–intensive fuels. Although not the highest, Bulgaria remains closer to coal–dependent systems like Czechia and Poland than to the EU’s low–carbon leaders in 2024.
Table 2: Carbon intensity of power industry among EU countries in 2024
| Country | Energy generation MWh | CO2 emissions of power industry Mt CO2eq/yr | CO2 intensity gCO₂ / kWh | % of total CO2 emissions of power industry in EU |
|---|---|---|---|---|
| Finland | 310 534 032 | 7,89 | 25 | 1,3% |
| Spain | 1 001 586 596 | 30,93 | 31 | 5,3% |
| Sweden | 161 579 956 | 5,83 | 36 | 1,0% |
| France | 523 714 680 | 22,11 | 42 | 3,8% |
| Croatia | 53 828 419 | 2,74 | 51 | 0,5% |
| Hungary | 129 289 701 | 7,38 | 57 | 1,3% |
| Romania | 204 620 945 | 14,68 | 72 | 2,5% |
| Netherlands | 424 922 060 | 31,02 | 73 | 5,3% |
| Portugal | 45 804 828 | 4,62 | 101 | 0,8% |
| Denmark | 34 473 485 | 4,18 | 121 | 0,7% |
| Slovakia | 29 467 095 | 3,86 | 131 | 0,7% |
| Lithuania | 7 667 555 | 1,04 | 136 | 0,2% |
| Austria | 66 148 764 | 9,95 | 150 | 1,7% |
| Ireland | 46 201 579 | 7,39 | 160 | 1,3% |
| Belgium | 72 487 494 | 12,59 | 174 | 2,1% |
| Latvia | 5 904 262 | 1,06 | 179 | 0,2% |
| Slovenia | 15 270 834 | 3,89 | 255 | 0,7% |
| Italy | 232 961 163 | 69,16 | 297 | 11,8% |
| Greece | 50 189 955 | 15,10 | 301 | 2,6% |
| Bulgaria | 36 703 255 | 11,76 | 320 | 2,0% |
| Germany | 437 653 767 | 171,40 | 392 | 29,1% |
| Czechia | 68 737 363 | 30,93 | 450 | 5,3% |
| Estonia | 4 930 413 | 2,98 | 605 | 0,5% |
| Poland | 158 451 852 | 112,75 | 712 | 19,2% |
The relatively high carbon intensity of Bulgaria’s energy sector can be attributed to several structural factors. Coal – especially lignite – continues to play a central role in Bulgaria’s energy mix, supported by domestic availability and energy security concerns. At the same time, although renewable energy has expanded rapidly in recent years – particularly solar – this growth started from a relatively low base. Institutional constraints, grid limitations, and investment uncertainty have also slowed the transition.
At the same time, there are clear signs of change. The rapid expansion of solar capacity and initial steps toward battery storage indicate that the system is beginning to shift, in part driven by market incentives rather than policy alone. This is an important point: carbon intensity is not just an environmental indicator – it increasingly reflects economic competitiveness. In a European market where carbon pricing plays a central role, more carbon–intensive electricity becomes more expensive.
This has direct implications for Bulgarian businesses. While households are largely shielded by regulated electricity prices, industrial consumers operate on the wholesale market and are directly exposed to carbon costs. As a result, carbon intensity can influence not only national emissions, but also the competitiveness of Bulgarian industry and its incentives to adapt consumption patterns.
Author: PhD Candidate Lyubimka Georgieva