Assessment of the Energy Security of EU Countries in Light of the Expansion of Renewable Energy Sources

Abstract

In response to disturbances in the European energy market due to Russia’s invasion of Ukraine, Europe had to strengthen its strategic resilience and reduce reliance on Russian gas imports by conserving energy, producing clean energy, and diversifying energy sources. A crucial aspect of this effort is assessing energy security, which serves as an indicator summarizing various aspects of energy development. This study evaluates the energy system’s ability to continuously, economically, and environmentally safely meet consumer needs in 28 European economies. This research employs non-linear (piecewise linear) normalization and the multiplicative convolution method, analyzing data from 2000 to 2021. Critical components of energy security examined include the resource supply, resource availability, consumption, compensability, efficiency, safety, and innovativeness. The findings indicate that most EU countries have sufficient-to-moderate levels of energy security. The histogram depicting the distribution of the energy security index and its components reveals that the innovation aspect within a country’s energy security framework has the lowest scores. This indicates insufficient innovation activity in developing and implementing new technologies and modern energy transportation and consumption methods. Consequently, the study highlights the inadequate effectiveness of current energy transition measures and offers recommendations for European policymakers based on these findings.

1. Introduction

In 2022, in response to the disturbances in the European energy market caused by Russia’s invasion of Ukraine, facing the task of enhancing Europe’s strategic resilience and reducing its dependence on Russian gas imports, the European Union implemented a plan to phase out Russian fossil fuel consumption by 2030 (REPowerEU Plan) [1], which focuses on conserving energy, generating clean energy, and diversifying energy sources. In an effort to urgently reduce the dependence on fossil fuels, EU member states are applying the following different models of energy transformation: expanding solar and wind energy, developing nuclear energy, or combining traditional and renewable energy sources with an emphasis on hydrogen technologies.

According to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [2], since the late 1800s, the global average temperature has increased by about 1.1 °C. Some experts declare that excessive CO₂ emissions contribute to global warming, the deterioration of the environment and the weather, the reduction in food and water supplies, the lowering of the sea level, and threats to the health of the global population [3]. The continuation of these trends and the lack of reforms in climate change management policies can increase the global temperature by 3 °C by the end of the century. At the same time, there is a prediction that a 2 °C reduction in the average annual temperature is possible by reducing CO₂ emissions by approximately 25% by 2030 compared to 2010 levels, and achieving net-zero emissions by 2070 [4].

The leading causes of global warming are the emission of greenhouse gases (mainly CO₂) caused by anthropogenic activities, the burning of fossil fuels, and energy production. In particular, power plants’ impact on the ecology in terms of CO₂ emissions is equal to metallurgic factories, and surpasses all other industries (30% of all solid particles emitted into the atmosphere, 63% of sulfur dioxide (SO₂), and more than 53% of nitrogen oxides (NO_x) pollute the air from stationary energy sources). Moreover, experts predict that energy consumption will increase by almost 1.5 times by 2050 [5]. According to the data of the World Economic Forum “Report on Global Risks 2023” [6], the energy supply crisis currently ranks first among the risks faced by humanity, ahead of the impact levels of the “Cost of Living Crisis”, “Rising Inflation”, “Food Crisis”, and “Cyber Attacks” on critical infrastructure. To mitigate the negative impact of energy consumption and economic activity on the environment, a transition, firstly, to low-carbon energy sources and, finally, to zero-carbon energy production, including renewable energy sources and low- and zero-energy technology, must be implemented [7].

This has contributed to the development of a significant number of programs and strategies at the international and national levels aimed at the transition to zero-carbon energy and the fight against climate change. The most important and influential document identifying the paths for reforming the European energy market is the “Energy Roadmap 2050”, implemented by the European Commission in 2012. According to this roadmap, the main direction of the development EU countries should be the creation of a new energy system model, which will make the whole system harmless, inexpensive, productive, and workable in the long term by increasing the segment of renewable energy sources to 66% and reducing greenhouse gas emissions by 80%. This would reduce energy-related CO₂ emissions by 85% and the energy demand by 41% by 2050.

Furthermore, the Feed-in Tariff (Fit) for 55 package (Council of the EU and the European Council, n.d.) should be mentioned [8]. This package of propositions to adjust and modernize EU legislation and advance new ideas aims to align EU policies with the climate goals set by the Council and the European Parliament. Directive 2012/27/EU on the energy efficiency of the European Parliament and the Council sets a goal to increase energy efficiency, to reduce energy utilization by 20%, and to intensify energy efficacy by 32.5% by 2030. Thus, by 2030, the European Union plans to decrease final energy consumption to 956 million tons of oil equivalent (Mtoe) and/or primary energy consumption to 1273 Mtoe, expanding energy consumption from renewable sources to 32%. And there is some evidence that the shift in energy production trends from traditional fossil fuel combustion to renewable energy technologies has resulted in a reduction in greenhouse gases by 7.1 g per euro of GDP in the EU-27 member states for every USD 1000 increase in GDP per capita [9].

Determining the integral level of energy security plays a crucial role, as it is an indicator that encapsulates various aspects of energy development. It allows for a wide-ranging assessment of the energy system’s capacity to meet current and future energy needs in a reliable, economical, and environmentally safe manner, ensuring adequate supply for a growing economy and defense requirements.

It is expedient to divide the analysis of the scientific publications into critical sections. The first section reviews the research focused on analyzing the benefits and challenges of transitioning to renewable energy, while the second section discusses the view of energy security.

One of the most important directions of the modern global energy policy is the transition to renewable energy, which is due to the decrease in the cost of electricity production from renewable sources and the need for deep decarbonization [10,11,12].

Achieving the goal of a carbon-neutral society by 2050 and replacing fossil fuels with renewable energy necessitates significant transformations in energy systems and profound changes in economics and society [13]. The deep decarbonization of the electricity sector requires not only technological improvements, but also the large-scale reform of energy markets, increasing the role of state regulation and international cooperation in creating stable and predictable market conditions for investors [14]. Many studies explore the role of government policies and the quality of governance, highlighting the importance of institutional quality in reducing CO₂ emissions, ensuring a green transition, and increasing the capacity of renewable energy sources [15,16,17,18,19].

While renewable energy can offer substantial environmental, social, and economic advantages, its rapid adoption may lead to various societal challenges and face numerous obstacles [20,21,22,23,24,25]. Renewable energy projects require significant initial investments, which is one of the biggest challenges for low- and middle-income countries. Banks often avoid financing such projects due to the high risks associated with political instability and the weak financial stability of countries [15,16]. The lack of modernized power grids and energy storage systems significantly limits the integration of renewable sources into the overall energy system. For EU countries, political incoherence is a serious obstacle to the development of renewable energy. Despite the adoption of a common EU policy on the transition to a climate-neutral economy by 2050, different approaches to implementing these goals significantly reduce the effectiveness of common market mechanisms in the field of decarbonization [18].

Some studies show that the speed and efficiency of renewable energy implementation depend on the geographical and economic characteristics of the regions [26]. Differences in the development of renewable energy sources are due to different levels of state support, industry characteristics, and energy strategies of the countries [27]. The greatest progress in the implementation of clean energy sources is made by countries with the strict regulation of CO₂ emissions [28]. Positive dynamics in the transition to green energy are characterized by Visegrad Group countries [29]. In recent years, EU countries have observed an increase in the share of renewable energy in the overall energy balance of the EU, which is due to the application of effective energy policy measures, such as the EU Emissions Trading System (EU ETS) and the Green Deal [30]. The USA and Canada have significant potential for the development of renewable energy sources [11]. A key element of the future energy system of Japan and South Korea is the development of hydrogen energy technologies [31].

Many studies have been devoted to the study of financial incentives for the development of renewable energy. Such incentives may include subsidies, tax breaks, green bonds, feed-in tariffs (Fits), emission trading schemes, and direct investment in renewable projects [32,33,34,35,36]. The conclusion of guaranteed power purchase contracts for renewable energy producers, and the support of green investment through tax incentives and subsidies, play an important role in achieving a 100% share of renewable energy sources in the country’s energy balance [37]. Equally important drivers of the development of renewable energy are international financing, strategic partnerships with developed countries, and the gradual updating of the regulatory framework [38]; facilitating access to credit programs for small- and medium-sized enterprises in the field of renewable energy is also an important factor in its development [11]. The active use of financial instruments in the European Union, China, and the USA has a positive impact on the development of renewable energy. At the same time, insufficient access to financing for renewable energy support programs in African and South American countries significantly limits their opportunities for the use of renewable resources [39]. Financial incentives, such as fixed feed-in tariffs (Fits), contribute to the growth of interest in energy-saving measures and the involvement of households in the use of clean energy [40,41]. CO₂ taxes and emission trading systems are effective tools for stimulating environmentally responsible behavior in favor of renewable sources [42].

A separate pool of works is dedicated to digitalization and its role in ensuring an efficient transition to renewable energy. A high level of digital transformation enhances the impact of strategic social responsibility on a company’s current and future financial success [43]. Digitalization and smart grid technologies contribute to the optimization of energy distribution, the reduction in losses, and the integration of renewable energy sources [44,45].

The expediency of the transition to renewable energy sources is due to their positive impact on public health. The improvement of public health by reducing air pollution is a result of implementing a strategy for switching to renewable energy sources [46,47]; the use of waste-to-energy technologies as an element of sustainable energy policy [48] received similar evidence for waste incineration and energy recovery.

Transitioning to renewable energy enables us to achieve the following two key objectives: cutting greenhouse gas production to mitigate future weather and climate impacts, and providing reliable, safe, timely, opportune, and commercial energy generation. Renewable energy can substantially benefit our energy security.

Energy security is a strategic priority for many countries, as it directly affects economic stability, national security, and the quality of life of the population [49,50]. From a macroeconomic viewpoint, energy security involves establishing a highly secure national energy system that is highly resilient to geopolitical threats [51]. Regarding environmental sustainability, energy security ensures stable energy consumption for each economy while reducing the reliance on fossil fuels and progressively increasing the quota of renewable energy sources [52].

Countries that depend on fossil fuel imports are more vulnerable to global energy crises, so public policy should be aimed at diversifying energy supplies, developing their own energy infrastructure, and integrating alternative energy sources [53,54]. Countries that rely on renewable energy have greater energy security in the long term, but this requires significant initial investments and the modernization of energy infrastructure [55].

In the European context, strategic decisions regarding energy security differ significantly between countries. Poland relies on nuclear energy and the preservation of coal-fired generation [56], increasing coal and oil reserves, which is a traditional approach to ensuring energy security [57], and also expanded the use of photovoltaic systems to reduce the dependence on traditional energy sources [58]. Germany focuses on an accelerated transition to renewable energy and the development of hydrogen technologies [56]. Lithuania, after the energy crises in Europe, implemented a strategy of reducing the dependence on Russian gas by developing its own liquefied natural gas terminals (LNG terminals) and expanding renewable energy generation [59].

Thus, the new regional model of energy security is based on the diversification of the energy supply, the modernization of infrastructure, and the integration of energy markets to reduce the impact of price fluctuations. For the energy balance of Ukraine, biofuels and waste are among the promising primary energy sources [60].

Countries that export gas, oil, and coal often fail to address critical vulnerabilities in their energy policies, which can lead to structural risks in the face of global market fluctuations [61]. Australia faces energy challenges caused by geopolitical competition, which requires a review of its energy sector development strategy and a reduction in dependence on fossil fuel exports [62]. At the same time, some countries are implementing a systemic approach to energy security, taking into account its inter-relationship with water and food resources. This contributes to reducing the dependence on imported energy resources and increasing the resilience of national economies.

However, long-term energy stability depends not only on physical resources but also on financial support mechanisms. The financial stability of energy markets is largely determined by the effectiveness of state support, the availability of investments in infrastructure modernization, and the development of CO₂ emission trading mechanisms (the EU ETS) [63], and countries with diversified energy markets demonstrate higher resilience to crisis events [64].

Thus, the results of the above analysis show that the primary strategies for restructuring economic systems towards an additive economy involve overhauling the types of energy production, modifying energy networks and interface spheres, and altering the structure of primary resources [65]. While considerable focus is on green energy’s efficiency and environmental benefits, its implications for overall energy security, especially in geopolitical risks and dependencies, require deeper investigation [66].

Despite the growing number of studies on renewable energy integration and energy security, significant research gaps remain, particularly in the following areas: (1) Insufficient comparative analyses: There is a lack of empirical studies systematically comparing different national approaches to the green energy transition and evaluating their relative success in achieving energy security and efficiency. Addressing this gap could foster a more nuanced understanding of best practices and assist in developing adaptable, context-sensitive policy frameworks. (2) Neglect of social acceptance and the political economy: Technical evaluations of energy security often overlook critical socio-political factors, such as public trust, institutional effectiveness, and civic engagement. These elements play a decisive role in shaping the legitimacy, pace, and spatial distribution of energy transitions, particularly in regions characterized by governance fragmentation or historical injustices. (3) Limited integration of innovation and compensatory mechanisms: Most existing energy security indices omit variables reflecting a country’s innovation capacity, financial resilience, and access to compensatory mechanisms (e.g., energy rents or adaptive subsidies), thus constraining the systemic assessment of long-term energy resilience. (4) Underexplored interdependencies between energy, innovation, and geopolitics: The dynamic relationship between renewable energy development, innovation potential, and energy consumption across diverse geopolitical and economic contexts remains insufficiently examined. This limits the ability to formulate robust cross-national strategies for energy independence.

Unlike previous studies, this article aims to fill these research gaps by developing a comprehensive index of energy security measures that incorporate innovation and compensatory factors, performing a cross-country comparative analysis of EU member states and Ukraine, and offering practical insights for policy harmonization and investment prioritization across the EU.

The paper is organized as follows: Section 2 outlines the materials and methods, describing the selection of indicators, the normalization procedures, and the calculation techniques for the composite index. Section 3 presents the empirical results, including descriptive statistics, country-level index values, and graphical interpretations. Section 4 provides an in-depth discussion of the findings in light of recent academic literature and geopolitical developments. Finally, Section 5 concludes with key takeaways, policy recommendations, and avenues for future research.

2. Materials and Methods

The evaluation of energy security will focus on seven main components that characterize the safety and efficiency of using traditional (oil and oil products, natural gas, coal, nuclear energy, and hydropower) and renewable (solar, wind, biomass, and other renewable sources) energy sources. Consequently, this study’s information base will consist of 31 indicators reflecting various aspects of the energy system’s operation (Appendix A). This research targets European countries, including EU member states and Ukraine, which attained EU candidate status in June 2022 and is actively implementing energy, environmental protection, and climate change reforms. Due to the lack of data for certain variables in specific periods, the study will cover the period 2000–2021.

Given the diverse nature of the variables comprising the statistical base for studying a country’s energy security level, the initial stage will involve normalizing the data to make them comparable. Following Yu et al. [67], Pele et al. [68], and Rangel de Castro Soares and Almeida [69], we selected a non-linear (piecewise linear) normalization method as our methodological tool, as it effectively smooths out significant differences in variables, including variations in units of measurement and positive or negative values. The obtained values will serve as the foundation for calculating the country’s energy security level.

In the subsequent stage, we will convert the normalized values to Harrington’s dimensionless desirability scale using the following formula:

$$X_i=\mathrm{e}\mathrm{x}\mathrm{p}(-\exp \left(-N_i\right))$$

(1)

where $X_i$ is the normalized value of the i-variable of the energy security level converted into the dimensionless scale of Harrington desirability and $N_i$ is the normalized value of the i-variable of the energy security level.

The obtained values will be used to construct dependence curves, illustrating the relationship between the normalized values of the i-variable of the energy security level (converted into the dimensionless Harrington desirability scale (di) and their factual values $\left(f_i\right)$).

The shape of the curve dictates the formula selection for transforming the analyzed data array into the dimensionless Harrington–Mencher desirability scale, following the algorithm proposed by Harrington.

For variables where the relationship curve between normalized values (converted into the Harrington desirability scale) and actual values forms an S-shaped symmetric growth curve (the first type), we will use the following formula:

$${XM}_i=\mathrm{e}\mathrm{x}\mathrm{p}(-\exp \left(9\times {({\displaystyle \frac{N_i-N_{i min}}{N_{i max}-N_{i min}}})}^{1.927}\right)-2)$$

(2)

where ${XM}_i$ is the normalized value of the i-variable of the energy security level converted into the dimensionless scale of Harrington–Mencher desirability, $N_{i min}$ is the minimum value of the normalized i-variable of the energy security level, and $N_{i max}$ is the maximum value of the normalized i-variable of the energy security level.

For variables where the relationship curve between normalized values converted into the dimensionless Harrington desirability scale and actual values forms the second type of curve (an S-shaped asymmetric growth curve), the transformation of variables will be conducted using the following formula:

$${XM}_i=\mathrm{e}\mathrm{x}\mathrm{p}(-\exp \left(9\times {({\displaystyle \frac{N_i-N_{i min}}{N_{i max}-N_{i min}}})}^{i_{comp}}\right)-2)$$

(3)

where ${XM}_i$ is the normalized value of the i-variable of the energy security level converted into the dimensionless scale of Harrington–Mencher desirability, $N_{i min}$ is the minimum value of the normalized i-variable of the energy security level, $N_{i max}$ is the maximum value of the normalized i-variable of the energy security level, and $i_{comp}$ is the adjustment coefficient that takes into account values of similar variables of the benchmark country, as follows:

$$i_{comp}={\displaystyle \frac{\mathrm{l}\mathrm{n}(2-ln(\ln \frac{1}{X_{i_{comp}}}))}{\ln \left(f_{i_{comp}}-N_{i min}\right)-\mathrm{l}\mathrm{n}(N_{i max}-N_{i min})}}$$

(4)

where $X_{i_{comp}}$ is the normalized value of the i-variable of the benchmark country’s energy security level converted into the dimensionless scale of Harrington desirability and $f_{i_{comp}}$ is the factual value of the i-variable of the benchmark country’s energy security level.

For variables where the relationship curve between normalized values converted into the dimensionless Harrington desirability scale and actual values forms the third type of curve (an S-shaped asymmetric curve with slow initial growth), we will utilize the following formula:

$${XM}_i=1-\mathrm{e}\mathrm{x}\mathrm{p}(-\exp \left(9\times {({\displaystyle \frac{N_{i max}-N_i}{N_{i max}-N_{i min}}})}^{i_{comp}}\right)-2)$$

(5)

For variables exhibiting the fourth type of curve (an S-shaped symmetric descending curve), we will employ the following formula:

$${XM}_i=\mathrm{e}\mathrm{x}\mathrm{p}(-\exp (-\left(9\times {\left({\displaystyle \frac{N_{i max}-N_i}{N_{i max}-N_{i min}}}\right)}^{1.927}\right)-2)$$

(6)

For the fifth type of curve (an S-shaped asymmetric curve with exponential decay), we will apply the following formula:

$${XM}_i=1-\mathrm{e}\mathrm{x}\mathrm{p}(-\exp (-\left(9\times {({\displaystyle \frac{N_{i max}-N_i}{N_{i max}-N_{i min}}})}^{i_{comp}}\right)-2)$$

(7)

$$\mathrm{where} i_{comp}={\displaystyle \frac{\mathrm{l}\mathrm{n}(2-ln(\ln \frac{1}{{1-X}_{i_{comp}}}))-ln9}{\ln \left(f_{i_{comp}}-N_{i min}\right)-\mathrm{l}\mathrm{n}(N_{i max}-N_{i min})}}$$

(8)

For variables demonstrating the sixth type of curve (an S-shaped asymmetric curve with a gradual initial decline), we will utilize the following formula:

$${XM}_i=\mathrm{e}\mathrm{x}\mathrm{p}(-\exp (-\left(9\times {({\displaystyle \frac{N_{i max}-N_i}{N_{i max}-N_{i min}}})}^{i_{comp}}\right)-2)$$

(9)

Next, we will compute the country’s energy security level using the multiplicative convolution method, as follows:

$$ESI={\sum }_{i=1}^n{a}_i{·XM}_i$$

(10)

where n is the number of variables and $a$_i is the weighting coefficient for each of the analyzed variables, calculated using the Fishburne formula, as follows:

$$a_i={\displaystyle \frac{2·(n-i+1)}{n·(n+1)}}$$

(11)

where n is the number of variables and i is the rank of the variables. The rank of each analyzed variable will be determined using expert assessment methods according to Quevedo et al. [70]. To ensure methodological transparency and reliability, a panel of 35 experts was selected based on their proven academic qualifications and professional experience in the field of energy security and renewable energy policy. The experts represented EU countries (Poland, Slovak Republic, Denmark, and Sweden). A modified Delphi method was used to reach consensus, as follows: the experts independently ranked the variables in the first round, followed by two iterative rounds of anonymous feedback and re-evaluation to converge their assessments. The final ranking was obtained by averaging the positions assigned in the last round.

The highest weights were assigned to variables reflecting environmental safety and energy efficiency. CO₂ emissions per capita (Saf1) and total greenhouse gas emissions (Saf2) received the highest weights of 0.044 each. The variables related to energy consumption (Con1–Con13) were uniformly weighted at 0.033, indicating moderate significance across multiple consumption dimensions. Compensatory indicators, such as resource rent for oil, coal, and gas (Comp1–Comp3), were assigned a weight of 0.025 each. Variables under the “Resource provision” component (RP1–RP8) were predominantly rated with a lower significance, ranging from 0.016 to 0.020, as were the Accessibility indicators (Ac1 and Ac2), which received a weight of 0.015. The lowest weighted variables belonged to the “Innovativeness” component (I1–I13), each receiving a weight of 0.007, reflecting the relatively lower perceived impact of patent activity on short-term energy security outcomes.

In the final stage of the study, the results will be interpreted both quantitatively and qualitatively using the criteria outlined in

Table 1. Characteristics of the country’s energy security levels.

Value	Level	Characteristic
0.8–1.0	High	The condition of the country’s energy system ensures the continuous, cost-effective, reliable, technically advanced, environmentally safe, and economically sustainable fulfilment of consumers’ present and future energy demands in quantities adequate to support economic growth and defense requirements. The country is capable of producing sufficient energy resources not only for domestic use but also for export.
0.6–0.8	Sufficient	Countries with an ample supply of domestic energy resources and the imperative to reform their energy markets to enhance the management efficiency of energy development components and boost the proportion of renewable energy sources.
0.4–0.6	Moderate	Countries with a moderate energy security level, attributed to inadequate domestic energy resources, limited capacity in their energy markets to adopt new energy-efficient and energy-saving technologies, modern control, management, and accounting systems for energy consumption, and establishing a competitive environment to ensure sustainable economic development.
0.2–0.4	Low	Countries lacking adequate energy resources experience high levels of energy dependence, an unbalanced and economically unjustified pricing policy for energy products, low readiness and innovation among energy market participants in adopting new energy-efficient and energy-saving technologies, and an energy sector that struggles to adapt to consumer needs and global market changes.
0–0.2	Critical	Countries facing a substantial deficit in energy resources find their energy systems vulnerable to external and internal threats. The volume of human-caused greenhouse gas emissions far surpasses the capacity of measures to reduce CO2 emissions and environmental clean-up efforts, exacerbated by the scarcity of energy resources, a minimal proportion of renewable energy sources, and an ineffective management framework for the country’s energy development.

.

3. Results

In the initial stage, we will conduct a comparative analysis of the energy security variables across 28 countries. The descriptive statistics presented in

Table 2. Descriptive statistics of energy security variables.

Variable	Minimum Value	Maximum Value	Average Value	Standard Deviation
RP1	−77.03	50.97	−0.07	16.02
RP2	0.00	251.48	24.10	37.61
RP3	0.00	304.63	27.08	53.75
RP4	0.24	402.40	57.53	82.79
RP5	0.00	172.77	18.09	30.67
RP6	0.00	530.51	57.36	103.61
RP7	0.00	93.59	5.83	9.91
RP8	0.00	451.53	32.71	81.19
Ac1	77.76	100.00	99.44	2.67
Ac2	92.76	100.00	99.75	0.94
Con1	15,779.98	113,106.20	42,330.54	17,458.33
Con2	0.00	58.40	16.55	11.70
Con3	0.00	1747.47	126.54	249.54
Con4	0.00	38,178.08	6514.54	6676.22
Con5	1.92	2976.69	203.21	523.05
Con6	0.00	30,380.21	8121.56	5550.22
Con7	0.00	26,194.45	2597.67	4271.66
Con8	0.00	50,470.69	8621.49	9152.53
Con9	0.00	23,852.87	3920.23	5287.17
Con10	0.00	80,359.70	16,397.78	12,010.95
Con11	0.00	7845.18	902.16	1352.85
Con12	0.00	1709.75	186.06	318.03
Con13	0.00	7361.92	891.37	1332.98
Comp1	0.00	2.00	0.16	0.30
Comp2	0.00	2.71	0.18	0.37
Comp3	0.00	2.05	0.16	0.32
Ef1	42.37	801.86	377.29	184.95
Ef2	1.11	15.20	3.67	1.54
Saf1	2.93	25.61	7.44	3.47
Saf2	−9.33	26.63	8.32	4.45
Saf3	0.00	3.64	0.47	0.69
I1	1.00	9966.00	447.92	1326.37
I2	0.00	50.00	9.01	11.29
I3	1.00	1227.00	49.93	138.70
I4	0.00	940.00	34.22	93.38
I5	0.00	129.00	6.87	16.26
I6	0.00	726.00	52.74	116.69
I7	0.00	144.00	8.23	15.63
I8	0.00	77.00	5.46	10.38
I9	0.00	451.00	27.90	55.51
I10	0.00	90.00	3.14	8.68
I11	0.00	1714.00	45.01	186.59
I12	0.00	94.00	3.89	10.41
I13	0.00	140.00	6.04	18.13

demonstrate significant differences in the implementation of energy policies among individual countries. The minimum values for most analyzed variables are near zero, and the standard deviation values indicate substantial variability among the variables. For instance, in 2022, Luxembourg reported a minimum electricity production from renewable sources (RP2) of 0 TWh, whereas Spain exceeded 120 TWh. Similarly, the minimum electricity demand (Con5) was 2.68 TWh in Malta compared to 505.4 TWh in France. Thus, it can be inferred that the formulation of national energy policies varies significantly among the analyzed countries, influencing their transition rates to renewable energy sources. Some countries also lack innovative initiatives to adopt energy-saving technologies and equipment.

In the subsequent phase, following the normalization of indicators to achieve comparable data (using normalization methods), curves were plotted depicting the relationship between normalized values transformed into the dimensionless Harrington desirability scale and the actual values of energy security indicators (Figure 1). These curves helped to identify the curve type (from the first to the fifth) and the corresponding formula (from 2 to 10) for converting the analyzed data into the dimensionless Harrington–Mencher desirability scale. Curves of the first and second types were predominant among the analyzed energy security indicators.

Calculating the country’s energy security level requires establishing weighting factors for each indicator. Using the Fishburne formula, weighting factors were determined (

Table 3. Weighting coefficients of a country’s energy security variables.

Variable	Rank	Weighting Coefficient	Variable	Rank	Weighting Coefficient
RP1	29	0.016	Con13	12	0.033
RP2	25	0.020	Comp1	20	0.025
RP3	25	0.020	Comp2	20	0.025
RP4	25	0.020	Comp3	20	0.025
RP5	25	0.020	Ef1	3.5	0.042
RP6	25	0.020	Ef2	3.5	0.042
RP7	25	0.020	Saf1	1.5	0.044
RP8	25	0.020	Saf2	1.5	0.044
Ac1	30.5	0.015	Saf3	5	0.040
Ac2	30.5	0.015	I1	38	0.007
Con1	12	0.033	I2	38	0.007
Con2	12	0.033	I3	38	0.007
Con3	12	0.033	I4	38	0.007
Con4	12	0.033	I5	38	0.007
Con5	12	0.033	I6	38	0.007
Con6	12	0.033	I7	38	0.007
Con7	12	0.033	I8	38	0.007
Con8	12	0.033	I9	38	0.007
Con9	12	0.033	I10	38	0.007
Con10	12	0.033	I11	38	0.007
Con11	12	0.033	I12	38	0.007
Con12	12	0.033	I13	38	0.007

). Subsequently, employing the multiplicative convolution method, the overall energy security level for European countries was computed.

In the final stage, we will analyze the results quantitatively and qualitatively using the threshold values of energy security levels provided in

Table 4. Grouping of countries by the level of energy security in 2021.

Value	Level	Countries
0.6–0.8	Sufficient	Slovak Republic, Estonia, Ireland, Slovenia, Spain, Belgium, Czech Republic, Austria, Poland, the Netherlands, Finland, France, Germany
0.4–0.6	Moderate	Cyprus, Croatia, Latvia, Portugal, Romania, Lithuania, Denmark, Luxembourg, Sweden, Hungary, Ukraine, Bulgaria, Italy, Greece
0–0.2	Critical	Malta

. The findings depicted in Figure 2 illustrate the varying trends in the energy security levels across different countries worldwide.

Thus, over the analyzed period, there has been a decline in energy security levels in Austria (from 0.713 in 2000 to 0.649 in 2021), Germany (from 0.8 to 0.697), and Spain (from 0.734 to 0.634), among others. Conversely, only 10 out of the 28 countries examined saw an increase in energy security levels, including Bulgaria (from 0.451 to 0.577), Estonia (from 0.504 to 0.618), Latvia (from 0.398 to 0.505), and Lithuania (from 0.398 to 0.534), among others.

Additionally, the results of grouping countries by their energy security levels in 2021 indicate that most countries have achieved a sufficient-to-moderate level of energy security (Table 4; Figure 3). Notably, none of the analyzed countries attained a high level of energy security, with Malta being the only country classified under the critical level of energy security.

Simultaneously, the histograms illustrating the distribution of values for the energy security index and its components (detailed in Appendix B) reveal that the innovative element in a country’s energy security framework exhibits the lowest values. This underscores the need for more thorough research and management strategies.

Thus, according to the analysis, most countries had sufficient or moderate levels of energy security, while Malta was at a critical level. Western and Central European countries, such as Germany, France, the Netherlands, and Poland, demonstrated greater stability thanks to the diversification of energy sources and developed infrastructure. At the same time, Southern and Eastern European countries, including Ukraine, Italy, and Bulgaria, faced challenges related to import dependence and insufficient energy innovation. Overall, no country achieved a high level of security, which indicates the need to increase investment in renewable energy sources, infrastructure projects and strategic energy policy planning.

4. Discussion

This article addresses several of the following critical issues: the ongoing increase in energy consumption, the dependence of countries on energy imports, and the limited share of renewable energy sources in the overall electricity production mix. Drawing on a literature review, it argues for the importance of developing an approach to assess a country’s energy security comprehensively, considering the security, production, and consumption of both traditional and renewable energy resources. This approach facilitates an evaluation of a country’s energy sector and aids in developing evidence-based tools for ensuring sustainable energy development.

This article proposes an integrated method to assess a country’s energy security level, combining 31 indicators across the following seven groups that evaluate the security and efficiency of individual energy sources: Resource provision, Accessibility, Consumption, Compensatory measures, Efficiency, Safety, and Innovativeness.

Based on an analysis of energy security trends among 28 European countries from 2000 to 2021, significant disparities in implementing national energy policies worldwide are highlighted. Countries like the Slovak Republic, Estonia, Ireland, Slovenia, Spain, Belgium, Czech Republic, Austria, Poland, the Netherlands, Finland, France, and Germany exhibit the highest (sufficient) levels of energy security. At the same time, Malta demonstrates the lowest (critical) level. The trend analysis reveals a decline in energy security levels in most of the countries examined (e.g., for Austria, it decreased from 0.713 in 2000 to 0.649 in 2021; for Germany, it decreased from 0.8 to 0.697; for Spain, it decreased from 0.734 to 0.634), with only ten countries showing improvement (e.g., for Bulgaria, it increased from 0.451 to 0.577; for Estonia, it increased from 0.504 to 0.618; for Latvia, it increased from 0.398 to 0.505; for Lithuania, it increased from 0.398 to 0.534, among others).

Additionally, the histogram illustrating the distribution of the energy security index and its components indicates that the innovative element in a country’s energy security framework has the lowest values. This reflects inadequate innovative activity to develop and implement new technologies and modern energy transportation and consumption methods. Therefore, this component requires prioritized attention from governments of countries with sufficient energy security levels. For countries with moderate energy security levels, the priority should focus on enhancing the energy consumption efficiency (within the “Efficiency” category) and increasing the share of renewable energy sources (within the “Security” category).

5. Conclusions

This study provides a comprehensive assessment of the energy security of EU countries in the context of the expansion of renewable energy sources. The findings highlight that, while most EU countries have achieved a sufficient or moderate level of energy security, no country has yet achieved a high level of energy security. The analysis highlights that energy security depends not only on the diversification of energy sources, but also on the effectiveness of energy policies, infrastructure modernization, and innovation in renewable energy technologies.

A key finding of this study is that the transition to renewable energy sources in EU countries remains uneven.

No EU country achieved a high level of energy security in the analyzed period (2000–2021), indicating the need for further improvements in infrastructure, innovation, and policy coordination.

While Western and Central European countries (e.g., Germany, France, the Netherlands, and Poland) demonstrate relatively higher energy security levels due to better energy diversification and infrastructure development, Southern and Eastern European countries (e.g., Ukraine, Italy, and Bulgaria) face challenges related to import dependence and low innovation activity in the energy sector. This discrepancy highlights the need for targeted policy measures to enhance the energy security in all EU member states.

This study also highlights the critical role of innovation in energy security. The results show that the lowest scores on the index of energy security are associated with the innovation component, indicating a lack of activity in the development and deployment of new energy technologies. This suggests that increasing investment in research and development, as well as promoting cooperation between governments, industry, and research institutions, are important for strengthening the EU’s energy sustainability.

At the same time, strengthening innovation in the energy sector, particularly in lower-performing states, requires targeted interventions aimed at enhancing both national and EU-level capacities for research, development, and deployment (RD&D). A key mechanism for promoting innovation in energy systems lies in the effective use of EU-wide instruments. For instance, Horizon Europe allocates more than EUR 95 billion to research and innovation initiatives, including those focused on clean energy technologies. Similarly, funding streams under the European Green Deal and the Just Transition Mechanism provide critical financial support to countries with structural energy disadvantages, enabling investments in smart grids, energy storage systems, and next-generation renewable technologies.

Facilitating equitable access to these funding opportunities, particularly for Central and Eastern European countries, can accelerate the convergence of innovation capacities across the EU. In addition, fostering regional innovation clusters and promoting cross-border public–private partnerships would stimulate knowledge exchange and reduce fragmentation in the deployment of energy technologies. Enhancing patent cooperation, for example, through intellectual property pooling under the European Patent Office framework, could further amplify synergies among innovators in member states with varying levels of R&D intensity.

Additionally, the geopolitical context resulting from Russia’s invasion of Ukraine highlights the strategic importance of innovation, not only as a tool for modernization, but also as a factor of resilience. Countries with a stronger innovation infrastructure are better positioned to rapidly diversify energy sources, reduce the dependence on politically unstable suppliers, and adapt to critical shocks. Therefore, future assessments of energy security should more explicitly account for the geopolitical dimensions of innovation policies and their role in enhancing systemic flexibility and independence.

In addition, Russia’s full-scale invasion of Ukraine in 2022 highlighted the strategic importance of innovation, not only as a means of technological modernization, but also as a key element of energy system resilience. The cessation of gas supplies from Russia, the EU’s largest external energy supplier, exposed the vulnerability of the EU’s energy dependence. Countries with more stable and innovative ecosystems were able to respond more flexibly and quickly to shocks by accelerating the deployment of domestic renewable energy, expanding the storage capacity, and investing in grid modernization. Germany, which has advanced technological and institutional capacity in solar and wind energy, was able to increase the integration of renewable energy and expand its infrastructure in a few months. Similarly, Lithuania, thanks to active innovation in energy infrastructure (e.g., the LNG terminal in Klaipeda and early investments in smart grids), effectively stopped importing Russian gas by mid-2022. At the same time, countries with less developed innovation potential had no alternatives to gas-fired heating and electricity generation, and faced problems in adapting to new realities. They also faced problems of grid congestion, lack of energy storage capacity, and low readiness to quickly scale up clean energy solutions.

In this context, strengthening energy security requires a comprehensive and multidimensional approach, which covers not only innovative development, but also the modernization of infrastructure, the enhancement of institutional capacity, effective regulatory policy, and strategic planning in the conditions of geopolitical instability. The key directions are the diversification of energy sources, the development of decentralized energy systems, the development of interconnections between EU member states, as well as an increase in the reserve capacity for energy storage.

In addition, an important task is to ensure the flexibility of energy markets, in particular, through the digitalization of demand management systems, the development of balancing mechanisms, and renewable sources into energy networks.

From an economic perspective, expanding the use of renewable energy sources offers the opportunity to increase energy independence while contributing to economic growth and employment. Countries that prioritize clean energy infrastructure and energy-efficient technologies are likely to reap long-term benefits, including reduced carbon emissions, reduced dependence on fossil fuel imports, and increased stability in energy markets.

While contributing to global energy market reform, this study acknowledges limitations and shortcomings that warrant consideration in future research. Specifically, the active development of “net-zero emissions” concepts underscores the significance of comparing human-caused emissions to carbon dioxide removals for evaluating energy policy effectiveness. The absence of data on carbon dioxide removals limits the scope of indicators and assessments of policy gaps towards achieving net-zero emissions. Thus, future research should explore aligning EU countries’ energy policies with “net-zero emissions” requirements. Furthermore, this study focused on a limited number of indicators within specific categories (“Accessibility”, “Compensatory”, and “Safety”), suggesting that future studies should encompass a broader range of indicators within these blocks.

In addition, a more comprehensive discussion would benefit from integrating recent insights from the political economy of energy transitions, with particular attention to the role of social acceptance and public trust in energy governance. These dimensions are increasingly recognized as decisive factors in the success or failure of renewable energy projects. While technical feasibility and economic efficiency remain central, the societal dimension of transition—involving citizens’ perceptions, participation, and local impacts—has emerged as a crucial determinant of the implementation speed and scope.

Numerous studies highlight that public opposition to renewable energy infrastructure often stems, not from the opposition to renewable energy per se, but from procedural injustices, such as the lack of stakeholder engagement, non-transparent decision-making processes, or the uneven distribution of costs and benefits. For example, Rosenbloom [11] emphasizes that transitions framed as top-down and technocratic tend to generate resistance, especially in rural or disadvantaged communities that feel excluded from planning processes. Similarly, Monyeia et al. demonstrate how concerns about energy justice and fairness in electricity decarbonization can undermine public support for low-carbon policies, particularly in contexts where communities are already facing poverty and energy insecurity [20].

Myroshnychenko et al. further elaborate on this by showing that regulatory barriers and the absence of consultative mechanisms significantly hinder entrepreneurship and start-up activity in renewable energy across several EU countries [24]. This results in a mismatch between energy policy objectives and local capacities or the willingness to engage, particularly in Central and Eastern Europe. Thus, social acceptance is not merely a soft factor but a strategic pillar of energy security, as it directly affects the pace, spatial distribution, and legitimacy of energy transitions.

Moreover, countries with low institutional trust, fragmented governance structures, or histories of environmental injustice are more likely to experience resistance to renewable energy deployment. This resistance can manifest in delayed permitting processes, legal challenges, or even the cancellation of infrastructure projects.

Considering this, future assessments of energy security and transition readiness should incorporate qualitative and quantitative indicators for energy security assessment, including energy and power components, reliance components, and police. Carbon dioxide removal (carbon dioxide removal) and the monitoring of progress in achieving net-zero emissions goals is also a promising area. Particularly noteworthy is the study of the influence of the financial mechanisms of the European Union on the convergence of the innovative potential of the member states. Expanding research into countries with different geopolitical and institutional contexts will allow us to form a more comprehensive vision of the vulnerability of energy systems and identify effective strategies for increasing their stability in the face of global challenges.