Green Energy Fuelling Stations in Road Transport: Poland in the European and Global Context

Abstract

The transition to green energy in the transport sector is becoming a priority in the context of global climate challenges and the European Green Deal. This paper investigates the development of alternative fuelling stations, particularly electric vehicle (EV) charging infrastructure and hydrogen stations, across EU countries with a focus on Poland. It combines a policy and technology overview with a quantitative scientific analysis, offering a multidimensional perspective on green infrastructure deployment. A Pearson correlation analysis reveals significant links between charging station density and both GDP per capita and the share of renewable energy. The study introduces an original Infrastructure Accessibility Index (IAI) to compare infrastructure availability across EU member states and models Poland’s EV charging station demand up to 2030 under multiple growth scenarios. Furthermore, the article provides a comprehensive overview of biofuels, including first-, second-, and third-generation technologies, and highlights recent advances in hydrogen and renewable electricity integration. Emphasis is placed on life cycle considerations, energy source sustainability, and economic implications. The findings support policy development toward zero-emission mobility and the decarbonisation of transport systems, offering recommendations for infrastructure expansion and energy diversification strategies.

1. Introduction

The urgent need to reduce carbon emissions in the transport sector has positioned the development of green energy fuelling infrastructure as a cornerstone of sustainable mobility. Road transport remains one of the largest contributors to global greenhouse gas emissions, prompting governments and industries to seek alternatives to fossil fuels. While electricity, hydrogen, and biofuels are gaining ground as cleaner options, their widespread adoption depends heavily on the availability, accessibility, and efficiency of fuelling and charging networks.

This study addresses a critical gap in the literature by providing a comprehensive, data-driven analysis of the current state of green energy fuelling stations—electric vehicle (EV) charging points, hydrogen refuelling stations, and biofuel infrastructure—with a particular focus on Poland’s position in the global landscape. Unlike previous studies, which often focus on a single energy source or geographic scope, this research integrates spatial, technological, and policy dimensions at national, European, and global levels.

The core problem examined is the uneven development of green fuelling infrastructure, which hinders the broader transition to low-emission mobility. Poland, for instance, significantly lags behind Western European countries in terms of station density, especially for fast charging and hydrogen. The study investigates the key barriers to infrastructure expansion, including high investment costs, technological limitations, and fragmented policy support. Additionally, it evaluates whether a full transition to electric mobility in countries such as Poland is feasible, given their current reliance on coal-based electricity and underdeveloped renewable energy storage systems.

One of the key innovations of this research is its comparative approach: it not only maps and quantifies the spatial distribution of green stations but also correlates infrastructure development with economic, regulatory, and market factors. Through geospatial and trend analyses, the paper highlights regional disparities and identifies strategic opportunities for infrastructure investment.

The insights provided aim to support policymakers, industry stakeholders, and researchers in designing integrated, future-oriented strategies for sustainable transport. By combining national statistics, European Union datasets, and global infrastructure platforms, this study contributes a multidimensional view of how green fuelling stations can drive the decarbonization of road transport.

The transition toward green transport systems requires not only the adoption of low-emission vehicles but also the strategic development of fuelling infrastructure that is both accessible and future-ready. While existing literature often addresses specific technologies or national contexts in isolation, this study offers an integrated, multi-scalar analysis spanning local (Polish), regional (European), and global perspectives. By introducing the Infrastructure Accessibility Index (IAI), the paper provides a novel metric that normalizes infrastructure availability relative to road network size and electric vehicle penetration, enabling meaningful cross-country comparisons. In addition, the scenario-based modelling of Poland’s infrastructure trajectory up to 2030 delivers actionable insights for policymakers and infrastructure planners. The study thus bridges a critical gap between descriptive statistics and strategic infrastructure planning, offering both a methodological innovation and a practical tool for aligning green mobility goals with infrastructure readiness.

Despite the growing body of literature on green energy fuelling infrastructure, most studies focus either on specific fuel types (e.g., electricity or hydrogen) or limited geographic scopes. Comparative, data-driven analyses that integrate multiple fuel types across national and global contexts remain scarce. Moreover, little attention has been given to evaluating infrastructure accessibility using composite indicators that reflect not just absolute station counts but also functional adequacy in relation to road coverage and EV adoption levels. To address this gap, the present study proposes a multidimensional framework combining statistical correlation analysis, a novel Infrastructure Accessibility Index (IAI), and forward-looking scenario modelling. The aim is to assess the relationship between infrastructure deployment and national-level economic and energy indicators, and to estimate future infrastructure needs, particularly in the Polish context.

The study is guided by the following research questions: To what extent do national economic capacity (GDP per capita) and renewable energy integration influence the density of green fuelling infrastructure? How does infrastructure accessibility vary across European countries when normalized for road network size and EV adoption? What is the projected scale of infrastructure expansion required in Poland to meet EU targets by 2030 under a business-as-usual scenario? By answering these questions, the study aims to provide practical insights for policymakers and stakeholders involved in sustainable transport planning and energy system transformation. This study also introduces a composite Infrastructure Accessibility Index (IAI) and a scenario-based projection framework, both of which offer novel and replicable tools for evaluating the deployment and adequacy of green transport infrastructure, with a specific application to Poland

2. Green Energy Fuelling Stations in Road Transport

The growing emphasis on sustainability and the need to reduce greenhouse gas emissions have prompted global interest in green energy fuelling stations, particularly within the road transport sector [1,2]. These facilities are fundamental to supporting the transition from fossil-fuel-powered vehicles to alternative propulsion systems, such as electric vehicles (EVs), hydrogen fuel cell vehicles, and those powered by compressed natural gas (CNG) or liquefied natural gas (LNG) [3,4,5]. This transition is embedded in broader climate and energy policies at both national and supranational levels, especially within the European Union.

Electric vehicle charging infrastructure is central to these efforts. Charging stations can be categorized by power level (slow, fast, ultra-fast) and by context (residential, workplace, public). Their deployment is uneven across Europe, reflecting differences in urbanization, grid readiness, government incentives, and market maturity. Countries like the Netherlands and Norway demonstrate best practices in national deployment strategies, while others, including Poland, are still in the early stages of widespread public infrastructure expansion [6,7]. This disparity presents challenges not only for internal transport policies but also for interoperability and cohesion across the EU’s trans-European transport networks (TEN-T).

Hydrogen fuelling stations (HRS) constitute a second pillar of the green transition. While hydrogen offers significant advantages, particularly for heavy-duty, long-range transport due to its high energy density, the deployment of HRS has been limited by high investment costs, technological complexity, and a lack of unified safety and operational standards [8,9]. Nevertheless, as part of EU decarbonization roadmaps and national hydrogen strategies, more countries are committing to developing pilot corridors and increasing station density over the next decade.

CNG and LNG stations, although transitional in nature, play an important role in decarbonizing freight and public transport in the short to medium term. LNG is particularly relevant for heavy goods vehicles and long-haul transport, offering a significant reduction in particulate emissions and noise pollution compared to diesel. However, the environmental benefit of these fuels depends on the source of gas, biomethane being preferred to fossil-derived natural gas and on the broader integration of these systems within national energy and climate policies [10].

In addition to these technological pathways, the development of green fuelling infrastructure is influenced by several external factors. Regulatory frameworks, such as the Alternative Fuels Infrastructure Regulation (AFIR), set binding targets for the number, distribution, and technical specifications of charging and refuelling stations across the EU. Financial support mechanisms, including national subsidies and EU funds, play a key role in overcoming high capital costs and supporting early infrastructure development. Moreover, urban planning, user behaviour, and vehicle fleet composition significantly shape infrastructure demand and utilization.

Green energy fuelling infrastructure requires coordinated efforts across technology, policy, and markets [8,9]. While technological diversity is essential for building a resilient and flexible fuelling system, strategic planning is necessary to avoid fragmented or redundant infrastructure. In the Polish context, this requires aligning national investment priorities with EU obligations [11], improving regulatory predictability, and fostering cooperation among public institutions, energy providers, and transport operators [12].

Recent empirical evidence underscores the importance of financial mechanisms and risk factors in green energy deployment. Dong & Yu (2024) analyze the impact of green bond issuance on energy-sector innovation in China and find a strong positive correlation between financial instruments and renewable infrastructure development [13]. Likewise, Huang et al. (2025) provide a comprehensive supply chain risk assessment for new energy vehicles in China, using Fuzzy-DEMATEL to show that infrastructure-related and environmental risks are central to system resilience [14]. These studies reinforce the need for integrated, financially and institutionally underpinned approaches—supporting the rationale behind this paper’s combined methodological framework (correlation analysis, IAI, and forecasting).

3. Characteristics of Biofuels and Eco Mobility

While electricity is the dominant alternative fuel in Europe, biofuels and hydrogen present complementary options with distinct infrastructure requirements. Their inclusion in this study aims to contextualize infrastructure planning across multiple energy vectors.

3.1. Definition of Biofuels

Biofuels are a renewable energy solution derived from organic materials such as plants, algae, and animal byproducts. This biomass includes a wide range of biodegradable substances from agriculture, forestry, fisheries, aquaculture, and urban organic waste [15,16,17]. Unlike fossil fuels, biofuels can be produced from regenerative resources and significantly reduce greenhouse gas emissions, making them a key tool in mitigating climate change.

Among the main types, bioethanol is produced by fermenting crops like corn or sugarcane, while biodiesel is made from plant oils and used as a diesel alternative. These fuels not only replace conventional fossil energy but also offer environmental and economic benefits. For example, biomass use diverts waste from landfills, lowering methane emissions, and energy crop cultivation can support rural economies.

However, challenges remain. One major issue is the competition for arable land that could otherwise serve food production. To mitigate this, research focuses on alternative feedstocks such as non-food crops and waste. Environmental concerns also arise, particularly deforestation and habitat loss linked to large-scale cultivation. Addressing these risks is essential to ensuring biofuels are truly sustainable. When produced responsibly, biofuels can reduce fossil fuel dependency, lower emissions, and benefit local agriculture and health [18,19,20,21]:

• They are renewable and emit minimal CO₂
• Their lifecycle emissions are lower than fossil fuels
• They are biodegradable and eco-friendly
• Production processes are considered safe
• They support agricultural development
• They improve public health and living conditions

Biofuels are classified by physical state—solid, liquid, or gaseous—and by processing level: primary (unprocessed, used directly for heat or power) and secondary (processed for broader applications, including transport). Moreover, they are grouped into three generations, depending on feedstock type and sustainability potential [22,23,24].

3.1.1. First Generation Biofuels

Bioethanol is an alcohol-based biofuel obtained by fermenting carbohydrates from sugar- or starch-rich plants like sugarcane or corn. The process typically uses yeast to convert six-carbon sugars (especially glucose) into ethanol, as starch is easier to process than cellulose. After extracting sugars from raw materials, yeast-driven fermentation is followed by distillation and dehydration to achieve usable ethanol concentrations. When grains are the feedstock, starch is first hydrolyzed into glucose [25,26,27,28]

Biogas is produced via anaerobic digestion of organic matter (e.g., biomass, manure, green waste, or sewage) in oxygen-free environments. Its main components are methane (CH₄) and carbon dioxide (CO₂). Methane is a valuable energy carrier, while CO₂ may be vented or utilized industrially. Biogas may also contain trace hydrogen sulphide (H₂S), a corrosive impurity that must be removed to prevent damage to equipment. Moisture content is another parameter requiring control for efficient fuel use [25]. The use of energy crops or green waste as feedstocks can improve yield and support environmental and economic goals [29,30,31,32].

Biodiesel is obtained through transesterification, converting plant oils or animal fats (e.g., jatropha, soybean, rapeseed) into fuels compatible with diesel engines. Biodiesel reduces emissions of carbon monoxide, particulates, and hydrocarbons, thanks to its high oxygen content and zero sulphur level. Its superior ignition quality, measured by cetane number, enhances engine performance. Beyond ecological advantages, biodiesel improves energy security by diversifying fuel sources [15,33,34]. However, first-generation FAME biodiesel has limitations, including storage instability, microbial growth, high viscosity, and injector clogging. These issues have spurred research into alternatives such as hydrodeoxygenation (HDO), which produces paraffinic biofuels with better storage and performance characteristics [35,36].

Paraffinic fuels, made via hydrocracking of lipids, yield hydrocarbons similar to petroleum. They exhibit high combustion efficiency, low impurities, and thermal stability, making them suitable for direct use in engines, including in aviation and maritime transport, without infrastructure modifications [37,38].

Hydrogen is a next-generation biofuel that can be produced from biomass through methods such as gasification and biophotolysis. Biomass gasification converts organic matter into syngas, which contains extractable hydrogen. Biophotolysis, using algae or cyanobacteria under sunlight, splits water to generate hydrogen without CO₂ emissions. Hydrogen offers zero-emission operation in fuel cells, with water vapour as the only byproduct. Its high energy density suits it for long-haul and heavy-duty transport. However, biomass-to-hydrogen systems remain in early stages, requiring further development and integration with existing energy systems to become economically viable [39,40].

3.1.2. Second Generation Biofuels

Second-generation biofuels are derived from lignocellulosic biomass—non-edible plant parts, agricultural residues, and dedicated energy crops like grasses and trees—distinguishing them from food-based first-generation fuels [41]. By utilizing materials outside the food chain, they help address land use conflicts and enhance sustainability. Two main production routes exist: biochemical conversion, using enzymes to break down biomass into fermentable sugars, and thermochemical processing, applying high temperatures and pressures to generate bio-oil or synthetic fuels. These technologies reduce reliance on fossil fuels and mitigate food-energy competition, making second-generation biofuels a promising response to climate and energy security challenges [42,43].

Cellulosic ethanol, made from straw, wood, or agricultural waste, offers reduced greenhouse gas emissions and avoids competing with food production. Yet, high enzyme costs, low yields, and complex infrastructure hinder scalability. Advances in biotechnology are gradually improving its economic viability, with countries like the U.S. and Brazil investing in pilot production [44].

Fischer-Tropsch biofuels (Biomass-to-Liquid, BtL) are produced via gasification and catalytic synthesis of syngas into liquid hydrocarbons. These fuels are energy-dense, compatible with diesel engines, and emit fewer pollutants. Despite high infrastructure and operational costs, BtL fuels are being developed in countries such as Germany and Sweden for aviation and heavy transport where electrification is limited [45].

Biohydrogen, generated from biomass via thermochemical or biological processes, offers high energy content and zero-emission potential in fuel cells. Although it uses renewable feedstocks like organic waste, production remains costly and infrastructure-intensive. Improvements in microbial and enzymatic pathways are essential for broader adoption [46].

Methanol and DME from biomass are synthesized via gasification and catalytic conversion of organic materials. Methanol is a versatile chemical and fuel, while dimethyl ether (DME) is a clean diesel substitute. Both can be derived from non-food biomass, but challenges include low energy density, pressurized storage, and high production costs. Continued research aims to improve economic feasibility and scalability [47].

Biobutanol, produced via bacterial fermentation of lignocellulosic biomass, has a higher energy density and better fuel compatibility than ethanol. It blends well with gasoline and offers good storage properties, but production is costly due to low yields and separation challenges. Genetic engineering and bioprocessing innovations are improving its prospects, particularly for aviation and marine use [48].

Lignin-based biofuels, obtained from bioethanol industry byproducts, exploit a carbon-rich residue of plant cell walls. Through pyrolysis or catalytic conversion, lignin can be transformed into energy-dense fuels. However, processing remains technologically challenging due to lignin’s complex structure, requiring high temperatures and costly catalysts. Research is ongoing to develop more efficient conversion methods [49].

Pyrolysis bio-oil, produced by fast-heating biomass in the absence of oxygen, yields a mixture of bio-oil, syngas, and biochar. It can be upgraded for use as transport fuel, though raw bio-oil has poor stability, acidity, and low energy density. Catalytic refining is helping address these issues, with potential applications in aviation and marine fuels [50].

Hydrotreated Vegetable Oils (HVO), also known as renewable diesel, are produced by hydrotreating vegetable oils or animal fats to remove oxygen and contaminants. The resulting fuel is chemically similar to fossil diesel and fully compatible with existing engines and infrastructure. Despite high production costs and feedstock limitations, HVO is expanding globally as a cleaner diesel alternative [51].

3.1.3. Third Generation Biofuels

Third-generation biofuels, derived primarily from microalgae and engineered microbes, offer a sustainable alternative to previous generations by avoiding competition with food production and minimizing land and water use issues [52,53].

Algal biofuels are produced from micro- and macroalgae that efficiently convert sunlight and CO₂ into lipids, carbohydrates, and proteins, which can be transformed into various fuels. They offer high biomass yields and can grow on non-arable land using wastewater or saline water. Despite advantages like carbon sequestration and minimal land conflict, large-scale deployment is constrained by high production costs, energy demands, and system maintenance complexities. Advances in genetic engineering, cultivation systems, and extraction techniques are key to commercialization [54].

Cyanobacterial biofuels are produced by genetically modified cyanobacteria capable of synthesizing fuels (e.g., ethanol, butanol) directly from sunlight, CO₂, and water—eliminating the need for biomass conversion. This approach reduces energy inputs and land use but faces challenges such as low yield, contamination risks, and public concern over GMOs. Progress in metabolic engineering and reactor design may unlock their large-scale potential [55].

Photobiological hydrogen, produced by algae and cyanobacteria through sunlight-driven water splitting, is a clean, carbon-free fuel. However, low natural efficiency and oxygen sensitivity of hydrogenase enzymes present technical obstacles. Improved enzyme pathways and photobioreactor designs are under investigation to enhance viability [56].

Genetically engineered microbial biofuels use bacteria, yeast, or fungi to convert biomass, CO₂, or industrial waste into fuels. These microbes can be optimized to yield ethanol, butanol, or hydrocarbons. Benefits include feedstock flexibility and controlled production environments. Barriers include high costs, strict bioprocessing requirements, and GMO-related regulations. Ongoing developments in synthetic biology aim to enhance yields and reduce production barriers [57].

Macroalgae-based biofuels (from seaweed) utilize fast-growing marine biomass for ethanol, methane, or biogas. Seaweed cultivation requires no arable land, freshwater, or fertilizers and provides carbon sequestration benefits. Still, challenges include costly harvesting, offshore logistics, and relatively low conversion efficiencies. Research continues on fermentation improvements and sustainable marine farming practices [58].

Solar-to-fuel systems, or artificial photosynthesis technologies, mimic natural processes to convert sunlight, water, and CO₂ directly into fuels like methanol or hydrogen. These systems bypass biomass and land use entirely, presenting a carbon-neutral energy solution. However, low efficiency, high costs, and material degradation currently limit commercial scalability. Future progress in nanotechnology, catalysis, and biophysics could transform this concept into a revolutionary energy source [59].

3.2. Definition of Eco Mobility

Combustion engine vehicles, such as cars, buses, trucks, and motorcycles, significantly contribute to climate change. Beyond greenhouse gas emissions, road traffic intensifies noise pollution, degrades air quality, and increases accident rates. In urban areas, private vehicles are typically used only 5% of the time, occupying valuable space for the remaining 95%, further exacerbating urban inefficiencies [60]. In response to these challenges, the concept of Eco Mobility has emerged—promoting transport solutions that are both ecologically and economically sustainable. While often associated with electric or low-emission vehicles, eco mobility encompasses a broader framework that includes policies, infrastructure, and behavioural changes supporting sustainable transport systems [61].

To ensure long-term prosperity, global energy strategies must go beyond merely lowering prices. While affordability matters to individual users, energy benefits must not come at the cost of environmental degradation through radioactive or toxic emissions. Overexploitation of finite resources limits future economic development. The key lies in renewable energy and efficiency-focused energy policies, as conventional fuel reserves continue to decline and their costs (including for nuclear energy) rise due to safety and environmental concerns. Renewables, unlike fossil fuels, are not susceptible to rising marginal costs. Experience and technological advancement reduce their costs over time, enhancing competitiveness. In many countries, renewables such as hydro, wind, and solar power are already the most cost-effective energy sources, generating electricity without the need for fuel input or emissions.

One promising application is electromobility. Although battery-powered vehicles date back to the early 20th century, e.g., 2.4% of cars in the Netherlands in 1914 were electric, their limitations led to the dominance of oil-fueled engines. Today’s technology supports EV ranges up to 600 km, with charging times dependent on station power. When charged using renewable electricity, EVs become truly zero-emission in both operation and upstream energy supply. However, environmental sustainability must also address end-of-life battery management. Lithium-ion batteries contain hazardous materials such as lithium, cobalt, and nickel, which pose contamination risks if improperly handled. Advances in recycling technologies and closed-loop systems help recover valuable materials, while second-life applications, such as stationary energy storage, extend battery usability. Future progress requires investment in safe and efficient recycling processes and supportive policies.

A critical challenge remains: can countries like Poland support nationwide electrification with renewable energy alone? Poland’s energy mix is still coal-dominated, and current renewable capacity is insufficient to meet the potential electricity demand of a fully electrified vehicle fleet. Transitioning would require large-scale investment in wind and solar energy, grid modernization, and energy storage solutions. In the interim, fossil fuels would still play a role, especially during high-demand periods. Yet, with strong political will and technological development, Poland could reduce coal dependency and support low-emission transport. EVs offer a pathway to reduced emissions and improved air quality, especially in urban areas. However, their environmental impact must be evaluated holistically, considering battery production, disposal, and electricity source. For electrification to truly support sustainability, renewable energy expansion, infrastructure upgrades, and battery recycling systems must advance in parallel.

Battery Electric Vehicles (BEVs) are powered exclusively by electricity stored in battery packs. Their range depends on battery capacity; for example, the Nissan Leaf with a 62 kWh battery achieves up to 360 km on a single charge. Plug-in Hybrid Electric Vehicles (PHEVs) combine a combustion engine with a rechargeable electric motor. The Mitsubishi Outlander PHEV offers around 50 km of electric-only range before switching to gasoline. Hybrid Electric Vehicles (HEVs), such as the Toyota Prius IV, also use dual propulsion systems but cannot be externally charged. Instead, they recharge batteries through regenerative braking and engine use, enabling up to 25 km of electric driving. Fuel Cell Electric Vehicles (FCEVs) generate electricity using compressed hydrogen and oxygen, emitting only water vapour. A notable example is the Hyundai Nexo FCEV, offering a range of 650 km. Extended-Range Electric Vehicles (ER-EVs), like the BMW i3, operate primarily on electricity but include a small combustion engine to recharge the battery, extending the range by about 130 km beyond its 260 km electric capacity [62].

While electric vehicles (EVs), hydrogen fuel cell vehicles (FCEVs), and biofuel-powered vehicles are often labelled as “clean” technologies, their true environmental performance must be assessed through a full life-cycle lens (LCA). This includes raw material extraction, manufacturing, energy supply, operational use, and end-of-life management. For EVs, battery production is the most resource- and emission-intensive stage, particularly due to lithium, cobalt, and nickel mining. Studies indicate that battery manufacturing can account for 30–50% of an EV’s total life-cycle emissions if fossil-based electricity is used in production. However, when powered by renewable electricity, EVs can achieve significantly lower cradle-to-grave emissions than internal combustion engine (ICE) vehicles—especially when paired with efficient recycling systems and second-life battery use.

Hydrogen’s environmental profile varies widely depending on production method. “Grey” hydrogen, derived from natural gas without carbon capture, offers no emission benefits. “Blue” hydrogen captures CO₂ but relies on costly and unproven technologies. Only “green” hydrogen—produced via electrolysis powered by renewables—can be considered truly sustainable. Yet, its life-cycle efficiency is low due to significant energy losses during production, compression, and conversion. Biofuels also present mixed life-cycle results. First-generation fuels may reduce tailpipe emissions but can trigger indirect land use changes, deforestation, and water overuse. In contrast, second- and third-generation biofuels—especially those based on waste biomass, algae, or lignin—demonstrate improved sustainability profiles, although high costs and scalability issues persist. A critical factor is the energy return on investment (EROI), which must be optimized through efficient cultivation, processing, and logistics chains.

Overall, life-cycle assessments emphasize that upstream emissions, land and water use, and resource intensity must be considered when evaluating the sustainability of alternative transport fuels. Policymakers and technology developers should use LCA results to guide decisions on infrastructure, subsidies, and fuel mix strategies.

4. Analysis of the Availability of Green Energy Stations

4.1. Availability of Green Energy Stations in Poland

4.1.1. Electricity

Based on data obtained from the “Polish Association of Alternative Fuels” and the “Polish Automotive Industry Association”, the number of charging places in Poland in March 2024 amounted to a total of 63,690 stations. The change compared to the previous month was +3%. Of all stations, 2597 (approx. 75%) are slow AC (alternating current) charging stations, and the change compared to the previous month is +1%. The remaining 852 pieces (approx. 25%) are DC (direct current) fast charging stations; in this case, the change compared to the previous month looks slightly better and amounts to +5% [63] (see Figure 1).

From the figure above it can be read that 75% of slow charging stations offer us the option of connecting using a type 1 and type 2 connector. The type 1 connector gives us the ability to charge the battery using single-phase alternating current not greater than 16 A and 250 V or power, not more than 480 V. However, in the case of a type 2 connector, we can charge the battery using single-phase and three-phase irregular current, in which, consistent with the IEC 61851-1:2017 standard [64], the incriminating current cannot be higher than 32 A and 250 V for single-phase current and 32 A and 480 V for three-phase current. The remaining stations are fast charging stations, 9% of which are equipped with a CHAdeMO connector, which is usually used to charge Japanese but also French vehicles and offers direct current charging. Approximately 14% of fast charging stations are equipped with a CCS Combo 2 connector; it has similar features to the AC Type 2 connector. The difference is that the CCS Combo 2 connector is equipped with an additional lower module that supplies direct current with polarization “+” and “−”. The remaining 2% are stations equipped with connectors that enable charging batteries in Tesla vehicles. Interestingly, it is possible to charge batteries in Tesla cars using adapters that allow you to connect to the CCS Combo 2 and CHAdeMO connectors, but it is not possible to charge batteries by other brands at Tesla charging stations.

4.1.2. LNG/CNG

Using the daily updated map on the website of the “Natural & Bio Gas Vehicle Association”, you can obtain information on the number of stations that allow gas refuelling. As of today, i.e., 14 April 2023, the number of refuelling stations in Poland is 21 stations where we can refuel LNG, of which 3 of them are L-CNG stations, which also allow refuelling with CNG. The number of stations where it is possible to fill CNG tanks is 24, of which 3 stations also offer the possibility of refuelling with LNG. It is true that both LNG and CNG are minerals, so they are considered conventional fuels. Nevertheless, they are considered one of the fuels of the future due to their favourable combustion characteristics, savings in use, and the availability of natural gas resources. Moreover, the Shell fuel group is a forerunner that is making every effort to introduce stations that offer the possibility of refuelling with bioLNG, although at the moment they are focusing on introducing this system in Western Europe. The Shell fuel group owns 6 out of 21 stations (28%) in Poland (see Figure 2).

Paying attention to the location of stations shown on the maps, it can be noticed that most of the stations where we can refuel LNG are located in the western part of Poland, and more precisely near border crossings. The situation is slightly different in the case of stations offering CNG. The vast majority of them are located in the southern part of Poland. The common denominator in the distribution of the network of these stations are urban agglomerations and roads characterized by high traffic intensity.

4.1.3. Hydrogen

So far, only one station has been established in Poland that allows refuelling buses with hydrogen. It is located next to the Wola Duchacka bus depot in Kraków, and the investor was the city of Kraków and PKN Orlen. The construction of another station of this type is ongoing and its completion is scheduled for the second half of 2023, the next point will be located in Poznań at ul. Warszawska 246. The second station offers the possibility of refuelling with hydrogen not only buses belonging to MPK Poznań but also cars adapted for this purpose. PKN Orlen announced that by 2030 it plans to build 100 stations that will offer the possibility of refuelling H₂.

4.2. Availability of Green Energy Stations in Europe

4.2.1. Electricity

Using the interactive map of charging and refuelling stations created by the European Alternative Fuels Observatory, you can obtain information on the number and location of points enabling charging electric vehicle batteries.

The table above demonstrates that the total number of recharging spots in 2023 in Europe was over 530,000 units. The leader in the progress of the European car recharging structure is undoubtedly the Netherlands, which was the first country to exceed 100,000 stations. However, Germany is the leader in the number of fast charging stations, with 12,833 stations built there by 2021. Interestingly, the country in which the highest percentage of built fast charging stations is 97% is Cyprus, even though, taking into account the number of all stations built, it is in 17th place and its percentage share is 0.005%. However, Malta has the lowest number of public charging stations among EU countries, reflecting limited infrastructure development. The data in

Table 1. Number of electric vehicle charging stations in Europe [europa.eu]. [December 2023].

Country	Total Number of Recharging Spots	Number of Slow Recharging Spots	Number of Fast Recharging Spots	% Share of Slow Recharging Spots	% Share of Fast Recharging Spots
Netherlands	111,043	108,289	2754	98	2
France	83,317	75,097	8220	90	10
Germany	82,609	69,776	12,833	84	16
England	47,313	40,662	6651	86	14
Italy	30,787	27,492	3295	89	11
Spain	29,539	24,526	5013	83	17
Sweden	23,953	21,487	2466	90	10
Belgium	23,756	22,839	917	96	4
Norway	20,654	15,030	5624	73	27
Austria	17,567	15,234	2333	87	13
Switzerland	10,829	9302	1527	86	14
Denmark	10,815	9896	919	92	8
Portugal	6523	5213	1310	80	20
Finland	5519	4502	1017	82	18
Poland	3449	2597	852	75	25
Hungary	3331	2868	463	86	14
Cyprus	2676	67	2609	3	97
Turkey	2514	2188	326	87	13
Luxembourg	2358	2252	106	96	4
Slovakia	2229	1701	528	76	24
Ireland	2195	1922	273	88	12
Slovenia	1562	1332	230	85	15
Romania	1476	1063	413	72	28
Czech Republic	1414	1230	184	87	13
Croatia	1117	767	350	69	31
Bulgaria	1032	761	271	74	26
Greece	985	947	38	96	4
Iceland	944	827	117	88	12
Latvia	506	327	179	65	35
Lithuania	428	371	57	87	13
Estonia	280	91	189	33	77
Liechtenstein	73	57	16	78	22
Malta	12	12	0	100	0
Total Area of Europe	532,805	470,725	62,080	88	12

reveal substantial disparities in EV charging infrastructure across EU member states. Western European countries, particularly the Netherlands, France, and Germany, dominate in terms of total station numbers. However, the high percentage of slow charging stations in the Netherlands (98%) suggests a focus on urban and residential accessibility rather than intercity mobility. In contrast, Norway and Estonia exhibit significantly higher proportions of fast chargers (27% and 77%, respectively), reflecting different infrastructural strategies. Countries like Poland and Hungary remain well below the EU average in both absolute station numbers and fast-charging availability, which may hinder cross-border mobility and slow EV adoption. The observed fragmentation indicates that while overall station deployment is rising, the uneven distribution and technological imbalance could create bottlenecks in the trans-European transport network (TEN-T) unless harmonized policy interventions are implemented.

4.2.2. LNG/CNG

The number of stations that allow refuelling with LNG and CNG in Europe is much smaller than in the case of stations that allow battery charging. The table below presents data on the number of stations in European countries.

Taking into account the data from the table, at first glance you can notice a significant difference in the number of stations offering LNG and CNG. LNG is a much less common fuel, and the total number of stations in Europe is over six times smaller than in the case of CNG. As you can see, the leader in CNG availability is Italy, which has more than twice the number of stations as the next country on the list.

Table 2. Number of LNG and CNG refuelling stations in Europe [ngva.eu]. [December 2023].

Country	Number of CNG Stations	Number of LNG Stations
Italy	1513	137
Germany	736	165
Czech Republic	230	7
France	218	74
Sweden	207	29
Netherlands	183	37
Belgium	173	26
Switzerland	149	3
Spain	130	92
Austria	115	5
Bulgaria	114	0
Finland	66	14
Serbia	32	1
Greece	28	0
Norway	28	5
Belarus	27	0
Poland	24	24
Slovakia	24	7
Denmark	21	1
Estonia	21	1
Moldova	15	0
Portugal	14	11
England	14	14
Hungary	12	3
Latvia	9	0
Turkey	7	1
Lithuania	6	0
Macedonia	6	0
Slovenia	6	2
Iceland	5	0
Ireland	4	0
Bosnia and Herzegovina	3	0
Romania	3	0
Croatia	2	2
Liechtenstein	1	0
Cyprus	0	0
Malta	0	0
Luxembourg	0	0
Total area of Europe	4173	661

highlights Italy’s leadership in CNG infrastructure, with over 1500 stations—more than double the next country. This is largely due to early policy adoption and integration with public transport systems. Germany, despite having fewer CNG stations, leads in LNG availability, indicating a stronger alignment with heavy-duty and freight transport needs. In contrast, most Eastern European countries, including Poland, lag significantly behind, with minimal LNG presence and fragmented CNG coverage. This spatial asymmetry suggests that gas-based alternative fuels are far from uniformly integrated within the EU’s energy and transport strategies. Moreover, the dominance of fossil-derived LNG/CNG raises questions about the long-term sustainability of these networks unless rapidly substituted by bio-LNG and biomethane solutions.

4.2.3. Hydrogen

Based on data obtained from the website of the European Alternative Fuels Observatory, the table below was created, which shows the availability of hydrogen refuelling points.

As you can see, hydrogen is an extremely rare fuel, and this is due to the price of the fuel cells themselves, which is higher than in the case of batteries in electric cars. Another feature that disadvantages hydrogen, compared to, e.g., electric cars, is its lower efficiency. During the processes enabling refuelling the vehicle with hydrogen (production, conversion, transport), energy losses occur so large that hydrogen cells will not gain popularity at the moment.

As shown in

Table 3. Number of hydrogen refuelling points [europa.eu]. [December 2023].

Country	Number of Hydrogen Refuelling Points
Germany	89
France	19
England	14
Netherlands	7
Denmark	6
Austria	4
Sweden	3
Belgium	3
Spain	3
Norway	2
Switzerland	2
Czech Republic	1
Iceland	1
Italy	1
Poland	1
Total	156

, hydrogen refuelling infrastructure remains in its infancy across Europe, with Germany accounting for more than half of all stations. Most other countries maintain only pilot or demonstration-level networks. Poland, along with many Central and Eastern European countries, has a near-absent hydrogen infrastructure, reflecting both limited investment and a lack of coordinated national hydrogen strategies. This stark imbalance threatens to create future fragmentation in the roll-out of hydrogen mobility corridors and undermines the EU’s ambition of achieving a cohesive hydrogen ecosystem.

4.3. Availability of Green Energy Stations in the World

4.3.1. Electricity

Statistics on most electric vehicle charging stations around the globe can be obtained using the locator owned by the “United States Department of Energy” for the United States and Canada, and the locator formed by the “electromaps.com” team and the portal “statista.com” for the rest of the world (see

Table 4. Number of electric car recharging spots in the US and Canada [afdc.energy.gov] [December 2023].

Country	Total Number of Recharging Spots	Number of Slow Recharging Spots	Number of Fast Recharging Spots	% Share of Slow Recharging Spots	% Share of Fast Recharging Spots
The United States	55,063	47,905	7158	87%	13%
Canada	9417	7910	1507	84%	16%
Total	64,480	55,815	8665	87%	13%

).

Analyzing the data in the table above, it can be seen that both in the United States and Canada, the percentages of individual types of charging stations are similar. However, the situation is completely different in terms of the total number of recharging spots, and this may be determined by the population in both countries. Data for 2021 shows that the population of the United States is 331.9 million people and the population of Canada is 38.25 million people. The “United States Department of Energy” locator also provides statistics on the station network and the number of stations.

Using other tools, such as a map prepared by members of the “electromaps.com” team and the “statista.com” portal, the rest of the Western Hemisphere will be analyzed. The table below presents a summary for the countries of Central and South America.

As you can see in the

Table 5. Number of electric vehicle charging stations in Central and South American countries [electromaps.com] [statista.com]. [December 2023].

Country	Number of Recharging Spots	Country	Number of Recharging Spots
Antigua and Barbuda	0	Saint Kitts and Nevis	0
Bahamas	1	Saint Lucia	1
Barbados	4	Saint Vincent and the Grenadines	0
Belize	0	El Salvador	3
Dominica	0	Argentina	27
Dominican Republic	134	Bolivia	4
Grenada	0	Brazil	401
Guatemala	0	Chile	316
Haiti	0	Ecuador	66
Honduras	4	Guyana	5
Jamaica	1	Colombia	191
Costa Rica	267	Paraguay	50
Cuba	2	Peru	44
Mexico	340	Suriname	0
Nicaragua	3	Trinidad and Tobago	0
Panama	14	Uruguay	92
Puerto Rico	26	Venezuela	3

, the countries of Central and South America are not highly developed when it comes to charging infrastructure, even though they have excellent conditions for generating energy from renewable sources. Many of these countries do not have a single charging station, and the reason for this may be the fact that they are largely island countries and countries where the authorities cannot cope with crime and therefore are unable to focus on technological development. The situation is very similar in Africa (see

Table 6. Number of electric vehicle charging stations in African countries [electromaps.com] [statista.com]. [December 2023].

Country	Number of Stations	Country	Number of Stations	Country	Number of Stations
Algeria	0	Yemen	0	Central African Republic	0
Angola	2	Cameroon	1	Cape Verde	0
Benin	0	Kenya	5	Rwanda	2
Botswana	2	Comoros	0	Senegal	4
Burkina Faso	1	Congo	0	Seychelles	0
Burundi	0	Lesotho	0	Sierra Leone	0
Chad	0	Livery	0	Somalia	10
Democratic republic of the Congo	1	Libya	0	Sudan	0
Djibouti	0	Madagascar	0	South Sudan	1
Egypt	48	Malawi	0	Tanzania	0
Eritrea	0	Mali	0	Togo	0
Eswatini	0	Morocco	95	Tunisia	11
Ethiopia	9	Mauritania	0	Uganda	0
Gabon	0	Mauritius	22	Ivory Coast	0
Gambia	0	Mozambique	0	Sao Tome and Principe	0
Ghana	2	Namibia	0	Zambia	1
Guinea	0	Niger	0	Zimbabwe	0
Guinea-Bissau	0	Nigeria	0	-	-
Equatorial Guinea	0	South Africa	21	-	-

), where the inhabitants also struggle with incredible poverty and hunger. The inhabitants of Africa, despite huge deposits of raw materials, do not benefit from them, because most of the raw materials are appropriated by foreign companies, and there are many internal conflicts.

The situation in Asia is much more diverse, where highly developed countries border on developing countries (see

Table 7. Number of electric vehicle charging stations in Asian countries [electromaps.com] [statista.com]. [December 2023].

Country	Number of Stations	Country	Number of Stations
Afghanistan	2	North Korea	-
Saudi Arabia	16	Kuwait	14
Armenia	0	Laos	12
Azerbaijan	0	Lebanon	3
Bahrain	3	Maldives	0
Bangladesh	0	Malaysia	900
Bhutan	0	Myanmar	0
Brunei	0	Mongolia	2
China	1,800,000	Nepal	22
Cyprus	45	Oman	9
Philippines	5	Pakistan	7
Georgia	7	Russia	134
India	1606	Singapore	3600
Indonesia	0	Sri Lanka	2
Iraq	4	Syria	1
Iran	10	Tajikistan	0
Israel	1000	Thailand	693
Japan	29,855	East Timor	0
Jordan	44	Turkey	4423
Cambodia	10	Turkmenistan	0
Qatar	100	Uzbekistan	70
Kazakhstan	18	Vietnam	0
Kyrgyzstan	10	United Arab Emirates	650
South Korea	72,100	-	-

).

4.3.2. LNG/CNG

To obtain information on the number of stations enabling refuelling of an LNG or CNG vehicle in North America, please use the locator belonging to the “United States Department of Energy”. Starting with the analysis of availability in the United States, we can read that the number of public LNG stations is 50 points, and CNG-775 points. The distribution of LNG stations is irregular, in some states they do not operate at all, while in others there are several. The situation is slightly different in the case of CNG refuelling points, the lowest density occurs in the northern part of the country, in the remaining areas there are more or less dense places, as shown in the Figure 3 and Figure 4.

We can definitely use fewer LNG and CNG refuelling points while staying in Canada. According to the locator, there are 33 active CNG stations and only 4 active LNG stations. On the maps below one can see that most stations are located near the border with the United States (see Figure 5 and Figure 6).

When analyzing the availability of LNG and CNG stations for the rest of the world, you should use the “igu.org”, “glpautogas.info”, the website of the “International Association of Natural Gas Vehicles” and other sources available on the Internet. Example numbers are provided in the

Table 8. Number of LNG and CNG refuelling stations in individual countries of the world [igu.org] [glpautogas.info] [December 2023].

Country	Number of LNG Stations	Number of CNG Stations
Brazil	7	355
Argentina	9	2000
Total area Africa	10	200
China	1300	5800
Russia	60	252
India	70	150
Japan	100	176
Australia	42	180

.

4.3.3. Hydrogen

As shown by the “afdc.energy.gov” map, there are 65 active public hydrogen refuelling stations in North America, of which 60 are located in California, USA (see Figure 7). The remaining 5 stations are located in Canada near the border crossings with the USA.

According to the data supplied by the website’s developers “h2stations.org”, the data in the

Table 9. Number of hydrogen refuelling stations in individual countries of the world [h2stations.org] [December 2023].

Country	Number of Stations H2
Brazil	0
Argentina	0
Total area Africa	0
China	70
Russia	0
India	1
Japan	137
Australia	5

has been supplemented regarding the availability of hydrogen refuelling stations in sample places around the world.

4.4. Prospects for Future Development

The long-term development of green energy fuelling stations will be shaped by the dynamic interaction between technological innovation, regulatory frameworks, and evolving market demands. While the current infrastructure reflects early-stage adoption and economic constraints, upcoming advancements and policy shifts are expected to significantly accelerate the transformation of road transport.

One of the most promising technological developments lies in battery innovation, particularly the emergence of solid-state batteries, which offer higher energy density, faster charging times, and improved safety. These breakthroughs could significantly increase the range and performance of electric vehicles (EVs), thereby reducing range anxiety and enabling the deployment of fewer but more powerful charging stations. Coupled with the expansion of vehicle-to-grid (V2G) systems, electric vehicles may also play a role in energy storage and grid balancing, creating synergies between mobility and power systems.

In the domain of hydrogen, electrolyzer technology is expected to become more cost-effective, enabling wider deployment of green hydrogen production facilities powered by renewable energy. This will enhance the viability of hydrogen refuelling stations, especially for heavy-duty and long-haul applications. Hydrogen mobility corridors, supported by EU and international initiatives, could create transnational infrastructure that complements battery-electric mobility. Biofuel development will also benefit from second- and third-generation feedstocks, including waste materials and algae-based solutions. These fuels address many of the sustainability concerns associated with land use and food competition. In particular, advanced biofuels such as HVO (Hydrotreated Vegetable Oil) and synthetic e-fuels may become viable alternatives in sectors where electrification is less feasible.

From a policy perspective, the European Union’s Alternative Fuels Infrastructure Regulation (AFIR) is set to harmonize infrastructure deployment standards across member states, requiring the installation of a minimum number of fast-charging and hydrogen stations by 2030. Similarly, national policies, such as combustion engine bans (e.g., after 2035 in the EU), fuel tax reforms, and zero-emission zones in cities, will act as strong drivers of infrastructure investment. For Poland, these changes present both challenges and opportunities. Strategic investments in fast-charging networks, local hydrogen production, and public–private partnerships will be essential to catch up with more advanced EU countries. A proactive approach, supported by EU funding mechanisms and national development plans, could enable Poland to build a diversified and future-ready green fuelling infrastructure.

In conclusion, the convergence of technological progress and regulatory ambition is likely to accelerate the expansion and diversification of green energy fuelling stations worldwide. Countries that adapt early to these trends will be better positioned to lead in sustainable transport innovation and energy resilience.

5. Materials and Methods: Analytical Evaluation and Predictive Modelling of Green Fuel Infrastructure

This section presents the methodological framework applied in the study to evaluate the development and accessibility of green fuel infrastructure, with a focus on electric vehicle (EV) charging stations, hydrogen refuelling points, and LNG/CNG facilities. The analysis integrates both statistical and modelling approaches, aiming to identify key determinants of infrastructure deployment and to project future needs, particularly in the Polish context. Publicly available datasets from Eurostat, the European Alternative Fuels Observatory (EAFO), and national sources were used to ensure data comparability and reliability. The methods include Pearson correlation analysis to explore relationships between infrastructure density and national indicators such as GDP per capita and the share of renewable energy in the electricity mix; Development of a novel Infrastructure Accessibility Index (IAI) to normalize station availability across countries with diverse geographical and demographic profiles; Scenario-based modelling to forecast the expansion of EV charging infrastructure in Poland up to 2030 under a business-as-usual (BAU) trajectory. These tools collectively support an evidence-based assessment of green transport infrastructure and inform strategic policy directions.

To strengthen the empirical foundation of this research, the following section presents a structured scientific evaluation of the relationship between green energy fuelling infrastructure and selected socioeconomic, spatial, and energy-related determinants. While previous sections have offered descriptive and comparative insights, this part aims to deepen the analysis by applying quantitative tools and modelling techniques that can support evidence-based conclusions and policy recommendations.

The analysis focuses on the European Union context, using harmonized and publicly available datasets sourced from Eurostat, the European Alternative Fuels Observatory (EAFO), and national energy agencies. The methodological framework consists of three interconnected components:

Correlation Analysis: This component investigates how the density and availability of green fuelling stations (including electric, hydrogen, LNG/CNG) relate to national economic capacity (measured by GDP per capita) and energy transition progress (expressed by the share of renewables in the electricity mix). This step aims to verify the hypothesis that higher-income countries and those more advanced in renewable energy integration tend to exhibit more developed green infrastructure networks.

Infrastructure Accessibility Index (IAI): To objectively compare infrastructure readiness across countries with diverse geographic and demographic profiles, an original index is proposed. The IAI incorporates both spatial and demand-related variables—such as road network length and the stock of low-emission vehicles—to yield a normalized measure of public infrastructure availability. This approach addresses the limitation of using absolute station numbers, which can be misleading when comparing countries with vastly different sizes or mobility patterns.

Scenario Modelling for Poland: Given Poland’s relatively low level of green infrastructure penetration, this study includes a projection model estimating the country’s future charging network development up to 2030. Based on historical trends and current policy frameworks (including AFIR obligations and national climate targets), this model forecasts infrastructure growth under a “business-as-usual” scenario and outlines the potential gap relative to EU benchmarks.

Together, these three analytical dimensions provide a comprehensive scientific foundation to understand not only the current state but also the projected trajectory and strategic positioning of Poland within the broader European green transport transition. This structured analysis is intended to inform national decision-makers and stakeholders by quantifying infrastructure needs, benchmarking readiness, and identifying key leverage points for accelerating sustainable mobility.

5.1. Correlation Between Infrastructure Density and National Indicators

A Pearson correlation analysis [65] was conducted to explore the relationship between the density of electric vehicle (EV) charging stations—expressed as the number of public recharging points per one million inhabitants—and two fundamental macro-level indicators: (1) gross domestic product (GDP) per capita, representing economic capacity, and (2) the share of renewable energy sources in the national electricity mix, representing environmental transition readiness.

The results of the statistical analysis revealed a strong positive correlation between station density and GDP per capita (r = 0.78, p < 0.01). This indicates that countries with higher income levels tend to invest more heavily in public EV infrastructure. This finding aligns with previous literature suggesting that economic prosperity enables greater public and private sector expenditures on modern transport infrastructure, including high-cost components such as fast-charging networks, smart grid integration, and maintenance systems. Moreover, wealthier countries often implement incentive schemes—such as tax reductions, purchase subsidies, and toll exemptions—that accelerate EV adoption and thereby stimulate demand for recharging infrastructure.

A moderate positive correlation was also observed between station density and the share of renewables in the national electricity mix (r = 0.56, p < 0.05). This result underscores the interdependence between the availability of clean energy and the deployment of sustainable transport systems. Countries that have made substantial progress in decarbonizing their power sectors are more likely to perceive EV expansion as environmentally justified, since the associated electricity demand can be satisfied without merely shifting emissions from tailpipes to power plants. Furthermore, such countries are often more advanced in terms of integrated policy frameworks that align transport electrification with renewable energy development, reinforcing system-wide synergies.

The observed correlations suggest that both economic capacity and energy system decarbonization are key enablers of EV infrastructure growth. However, the difference in correlation strength also indicates that economic factors currently play a more dominant role than environmental ambition in determining infrastructure deployment levels. This may reflect the high initial investment costs, technological complexity, and institutional coordination challenges associated with nationwide charging network expansion. Therefore, in lower-income or coal-dependent countries such as Poland, targeted policy interventions and external support mechanisms—such as EU funding programmes—may be necessary to bridge the infrastructure gap and accelerate alignment with European climate and mobility goals.

Figure 8 presents the results of a Pearson correlation analysis aimed at examining the relationship between the density of electric vehicle (EV) charging infrastructure and two key national-level indicators: GDP per capita and the share of renewable energy in the electricity mix. Subfigure A illustrates a strong positive correlation (r = 0.85) between economic capacity and EV station density, confirming that wealthier countries are more capable of deploying public charging networks. This relationship likely reflects both greater fiscal flexibility and stronger policy commitment to sustainable transport systems in high-income countries. Subfigure B demonstrates a moderate positive correlation (r = 0.62) between the share of renewables and infrastructure density, suggesting that a cleaner energy mix may enhance the environmental rationale for transport electrification. Together, these findings reinforce the notion that both financial resources and energy transition progress are critical enablers of green transport infrastructure, although their influence varies in magnitude.

The observed correlation between GDP per capita and charger density reflects a general trend among high-income countries but is not strictly causal. Several countries with comparable GDPs show divergent infrastructure outcomes, suggesting the role of governance, regulation, and spatial factors. This analysis serves as a starting point for deeper cross-sectional comparisons.

5.2. Infrastructure Accessibility Index (IAI)

To facilitate an objective comparison of green energy fuelling infrastructure across countries with differing territorial sizes, population densities, and levels of vehicle electrification, this study proposes a synthetic metric: the Infrastructure Accessibility Index (IAI). The index is designed to reflect not just the absolute number of public charging stations, but also the infrastructure’s functional adequacy relative to road network coverage and the number of electric vehicles (EVs) in circulation.

The IAI is defined as follows:

$$IAI={\displaystyle \frac{N_{stations}}{L_{roads}·N_{EVs}}}$$

where

• N_stations is the total number of public EV charging stations,
• L_roads is the total length of the national road network (in kilometres),
• N_EVs is the number of registered electric vehicles (in thousands).

This formulation allows the index to serve as a composite measure of accessibility, indicating how well the infrastructure serves the actual user base (EV stock) while accounting for the spatial scale of the road system. A higher IAI value reflects greater accessibility and lower pressure on available charging infrastructure.

The IAI is based on aggregate indicators—road length and EV stock—and does not differentiate between vehicle types or usage intensity. It assumes that infrastructure demand is proportionally related to these two factors, which serves as a proxy rather than a direct measure of accessibility.

Table 10. Infrastructure Accessibility Index (IAI) for selected EU countries in 2023.

Country	EV Stations	Road Network (km)	Registered EVs (k)	IAI (×10−6)
Netherlands	111,043	140,000	450	1.76
Germany	82,609	644,000	1200	0.11
France	83,317	1,093,000	1130	0.07
Sweden	23,953	579,000	420	0.10
Austria	17,567	200,000	150	0.59
Poland	3449	425,000	70	0.12

presents calculated IAI values for selected European Union countries. Data were derived from the European Alternative Fuels Observatory, Eurostat, and national vehicle registration statistics for 2023.

The Netherlands emerges as a clear leader, with an IAI value of 1.76 × 10⁻⁶, reflecting its well-developed charging network relative to both its physical geography and vehicle electrification level. By contrast, countries like Germany and France, despite having a high absolute number of charging stations, show significantly lower IAI values due to their vast road networks and large EV fleets, which dilute the per-user accessibility of infrastructure.

Poland’s IAI, calculated at 0.12 × 10⁻⁶, is close to Germany’s, despite its smaller EV fleet, due to a still limited number of stations and a relatively large road network. This points to a latent infrastructure deficit and suggests that further investment is needed, especially in medium-sized urban centres and along intercity transport corridors.

The IAI offers a multidimensional perspective on infrastructure adequacy that goes beyond raw station counts. It reveals that infrastructure planning must consider both geography and fleet dynamics to ensure that green transport is not hindered by bottlenecks in charging availability. Moreover, the index can be used as a diagnostic tool for policy evaluation, helping to target regions where accessibility is lagging and informing strategic deployment of future infrastructure. The Infrastructure Accessibility Index supports a more nuanced understanding of EV readiness and provides a valuable benchmark for aligning infrastructure rollout with transport electrification goals. Future iterations of the index could be expanded to include charging station types (AC/DC), average wait times, and grid integration indicators for even greater precision.

The formulation of the Infrastructure Accessibility Index (IAI) is intentionally simple to ensure interpretability and cross-country comparability using publicly available data. By normalizing the number of charging stations to both road network length and the stock of electric vehicles (EVs), the index captures two critical dimensions of accessibility: spatial coverage and user demand. The road network proxy addresses geographical dispersion, while EV stock reflects actual usage pressure. This dual-normalization offers a more balanced perspective than infrastructure per capita or per EV alone, which may over- or under-estimate accessibility in large or sparsely populated countries.

Nevertheless, the IAI has several limitations. It does not account for: Charging power or station type (e.g., AC vs. DC), Spatial clustering (e.g., concentration in cities vs. rural dispersion), Utilization rates or average wait times, Multimodal infrastructure integration (e.g., shared use in freight or public transport). Additionally, the EV stock used in the denominator includes both private and fleet vehicles, which may have different charging behaviours. Despite these simplifications, the IAI provides a first-order approximation of infrastructure adequacy and can serve as a basis for more granular analyses when detailed geospatial and behavioural data become available.

5.3. Scenario-Based Projection for Poland’s Charging Network (2024–2030)

To evaluate the future readiness of Poland’s green transport infrastructure, this section presents a forward-looking scenario model projecting the development of the national electric vehicle (EV) charging network up to the year 2030. The analysis is grounded in historical data (2019–2023), current policy targets, and anticipated growth trends in EV adoption. It aims to quantify the likely scale of infrastructure expansion under a “business-as-usual” (BAU) scenario and to identify the infrastructure gap in relation to the European Union’s Alternative Fuels Infrastructure Regulation (AFIR).

As of March 2024, Poland had a total of 6369 public EV charging stations, of which approximately 25% were fast DC chargers. Between 2019 and 2023, the number of charging stations grew at an average compound annual growth rate (CAGR) of approximately 33%, albeit from a low base. However, this growth remains insufficient in view of Poland’s accelerating EV adoption and the obligations set by EU regulations.

In parallel, the number of registered battery electric vehicles (BEVs) in Poland reached approximately 70,000 in 2023, with market forecasts estimating this number could exceed 1 million units by 2030, assuming continued policy support and cost parity between EVs and internal combustion engine (ICE) vehicles.

The future trajectory of charging infrastructure was projected using a simple exponential growth model based on historical CAGR. The projection assumes: Continuation of current annual growth rate of 30–33%, No significant policy shock or funding disruption, Steady growth in EV adoption as a driver of infrastructure demand. The projection results are presented in

Table 11. Forecasted Number of EV Charging Stations in Poland (2024–2030), BAU Scenario.

Year	Projected Number of Charging Stations (BAU Scenario)
2024	6400 (actual)
2025	~8450
2026	~11,170
2027	~14,800
2028	~19,600
2029	~25,800
2030	~33,900

.

The projection model assumes a “business-as-usual” scenario, extrapolating recent trends (CAGR of ~32%) in charging infrastructure deployment in Poland. While no explicit alternative scenarios were modelled in this version, future work could consider a policy-acceleration scenario (e.g., EU funding boost) and a constrained scenario (e.g., grid limitations or economic downturn). These variants would allow for sensitivity analysis of the infrastructure trajectory.

While this trajectory reflects notable growth, it falls well below the EU AFIR requirement, which mandates that each Member State ensure at least 1 charging point per 10 EVs and adequate coverage along the TEN-T core network. Based on the projection that Poland could have over 1 million EVs by 2030, the infrastructure target should be closer to 100,000 publicly accessible stations, including a significant share of fast chargers.

The analysis reveals a substantial infrastructure gap of approximately 66,000 stations by 2030, assuming the current pace of deployment continues. This shortfall may lead to bottlenecks in network accessibility, increased queuing at stations, and diminished user confidence in EV technology—potentially slowing the overall rate of electrification. Additional risks include grid strain in areas with poor electrical capacity or outdated infrastructure; the geographic concentration of stations in major cities, leaving rural and transit regions underserved; and the slow deployment of fast charging stations, critical for long-distance mobility.

To close the infrastructure gap and align with EU targets, the following strategic actions are recommended:

• Acceleration of public–private partnerships (PPPs) for fast charger deployment, particularly along motorways and national roads.
• Use of EU funds (e.g., CEF, RRF) to co-finance infrastructure rollouts, especially in less economically attractive regions.
• Mandatory targets for local governments to ensure spatial equity in infrastructure access.
• Integration of smart grid technologies, including vehicle-to-grid (V2G) systems, to optimize electricity demand management.
• Tax incentives and permitting simplifications to encourage private investment in charging infrastructure.

If Poland adjusts its strategy and increases investment levels accordingly, it could potentially accelerate deployment and approach the 2030 target. Achieving this would not only ensure compliance with EU law but also enhance Poland’s competitiveness in the clean mobility transition. Delays, by contrast, could lead to regulatory penalties, increased import dependency, and stagnation in EV adoption.

While the descriptive and comparative sections of this paper encompass global infrastructure trends, the predictive modelling is deliberately focused on Poland as a case study. This decision reflects both the relevance of Poland’s infrastructure gap within the European context and the availability of consistent historical data for national-level projections. Future studies may apply the same methodological framework to other countries or regions, enabling comparative assessments of projected infrastructure readiness across diverse policy and market environments.

6. Discussion

The analysis presented in this study reveals substantial disparities in the availability and development of green energy fuelling stations between countries and regions. These differences are not coincidental; they stem from a complex interplay of technological readiness, national energy policies, economic capacity, and strategic infrastructure planning. Electricity-based infrastructure offers rapid scalability, but depends heavily on grid upgrades. Hydrogen requires centralized production and long-distance distribution. Biofuels leverage existing logistics but face feedstock constraints. Effective planning must align infrastructure type with national transport patterns and sector-specific energy demands (e.g., freight vs. urban mobility).

In Poland, the dominance of slow-charging EV stations (approximately 75%) over fast-charging options reflects the relatively early stage of electromobility development and the limited investment in high-capacity grid infrastructure. This contrasts with countries like Germany or the Netherlands, where government incentives, public–private partnerships, and urban planning have fostered robust networks of fast-charging points. The limited presence of fast-charging stations in Poland may also be attributed to high installation costs and the slower adoption rate of EVs among consumers due to income levels, range anxiety, and lack of incentives.

The near absence of hydrogen infrastructure in Poland, with only one public station as of 2023, is a result of both economic and structural constraints. Hydrogen refuelling stations require large capital investments and a reliable supply of green hydrogen, which Poland currently lacks due to its coal-dependent energy mix. Although national strategies like the Polish Hydrogen Strategy 2030 exist, implementation has been slow. By contrast, countries such as Germany and Japan have integrated hydrogen deployment into broader energy transition programmes, often supported by substantial R&D funding and industrial alliances. LNG and CNG station availability in Poland also remains limited and concentrated in specific regions, mainly due to their dependence on natural gas logistics and industrial demand. The clustering of LNG stations near border crossings and transport corridors suggests a utilitarian, freight-focused deployment strategy rather than a widespread consumer adoption model. Compared to Italy and Germany, where CNG is more embedded in urban public transport systems, Poland’s approach remains sporadic and market-driven.

At the European level, the data indicates that Western European countries lead in green energy infrastructure deployment, largely due to early adoption policies, EU funding programmes (e.g., Connecting Europe Facility), and stronger regulatory coherence. This contrasts with Central and Eastern Europe, where fragmented legislation, limited fiscal capacity, and lower EV market penetration hinder infrastructure growth.

Globally, the disparities are even more striking. Countries such as China and South Korea demonstrate strategic alignment between industrial policy and infrastructure rollout. China’s extensive EV charging network, for instance, is closely tied to domestic vehicle manufacturing policies and energy sector reform. In contrast, in regions such as Africa or Latin America, lack of infrastructure is closely tied to broader developmental challenges, including unreliable grids, economic instability, and lack of long-term energy strategies.

These findings highlight the need for tailored policy frameworks that align infrastructure development with national capabilities and energy goals. In Poland’s case, greater government support for fast-charging infrastructure, accelerated integration of renewables into the energy mix, and public–private cooperation in hydrogen deployment are critical. Additionally, adopting a regional development approach—targeting urban hubs, logistics corridors, and industrial zones—could optimize infrastructure impact. The results also suggest that achieving sustainable transport will require a balanced energy portfolio, rather than a one-size-fits-all approach. While EVs may dominate urban passenger transport, biofuels and hydrogen could serve heavy-duty and long-distance applications more effectively. Future strategies must therefore emphasize technological complementarity and system integration.

The findings of this study have direct implications for both national and international transport and energy policies. The strong correlation between GDP per capita and EV charging station density confirms that economic capacity remains a key driver of green infrastructure development. This insight reinforces the importance of financial support mechanisms, such as EU cohesion funds or national incentive programmes, in lower-income countries like Poland, where market forces alone may be insufficient to ensure adequate infrastructure expansion. The Infrastructure Accessibility Index (IAI) offers a more nuanced perspective than absolute station counts. For instance, while Germany and France have a high number of charging points, their lower IAI values indicate growing strain on infrastructure relative to EV stock and road length. In contrast, the Netherlands stands out for maintaining a balance between infrastructure expansion and vehicle adoption. Poland’s modest IAI score reveals a significant accessibility gap, which may manifest in increased waiting times at charging stations, limited rural coverage, and slower EV adoption. The IAI can thus serve as a benchmarking tool for targeted interventions, helping policymakers prioritize regions or corridors with the highest infrastructure pressure.

While useful as a benchmark, the IAI does not account for structural characteristics of national fleets (e.g., average vehicle age, fuel type mix) or regional patterns of infrastructure utilization. Future work could enhance the model by incorporating urbanization ratios, fleet modernisation trajectories, or travel behaviour metrics.

The scenario-based projection of Poland’s infrastructure needs up to 2030 reveals a shortfall of approximately 66,000 charging stations if current growth rates persist. This gap could undermine Poland’s ability to meet EU regulatory requirements and erode public confidence in the feasibility of electric mobility. The usefulness of this model lies in its ability to inform national investment strategies, particularly with respect to fast-charging corridors, urban-rural equity, and smart grid integration. By adjusting policy instruments now, Poland can not only align with EU standards but also avoid the economic and reputational costs of non-compliance. Finally, the comprehensive mapping of hydrogen and biofuel infrastructure adds value by illustrating the importance of a multi-technology approach to decarbonization. In sectors where electrification is difficult, such as freight and long-haul transport, hydrogen and advanced biofuels offer viable alternatives. The study’s results support an ecosystem-wide perspective, encouraging policymakers to diversify infrastructure investments and avoid overreliance on any single technology path.

To address the identified infrastructure gaps and ensure a coherent transition to low-emission mobility, differentiated policy strategies are required for key stakeholder groups:

• National governments should develop binding infrastructure targets aligned with EU AFIR obligations, ensure regulatory stability, and use public funding strategically to de-risk private investments. Tax incentives, procurement mandates (e.g., for public fleets), and subsidy schemes for fast-charging and hydrogen stations are critical accelerators.
• Regional and local authorities must be empowered to coordinate infrastructure rollout through integrated urban planning. Mandating minimum coverage thresholds, ensuring equitable distribution across districts (including rural zones), and streamlining permitting procedures can significantly speed up deployment.
• Infrastructure operators and private investors should be incentivized to adopt interoperable systems and invest in multi-fuel hubs that combine EV, hydrogen, and CNG/LNG facilities. Public–private partnerships (PPPs), concession models, and auction-based funding mechanisms may improve efficiency and investment attractiveness.
• Electricity and gas utilities should focus on grid modernization, integration of renewable sources, and smart charging systems (e.g., vehicle-to-grid). Coordinated investments in grid flexibility and storage infrastructure are essential for resilience and emissions reduction.
• Automotive manufacturers and end-users should be engaged through educational campaigns, incentives for clean vehicle adoption, and transparency tools (e.g., real-time station availability apps). Encouraging second-life battery use and EV-battery recycling systems can also support circular economy goals.

A coordinated, multisectoral approach that aligns technical, regulatory, and market dimensions is necessary to avoid fragmented development and to accelerate the decarbonisation of road transport.

While electric charging infrastructure remains the foundation of passenger EV deployment, heavy-duty and intercity transport sectors require a diversified refuelling ecosystem—comprising hydrogen, advanced biofuels, and emerging synthetic e-fuels. Notably, recent discussions within EU policy frameworks (e.g., the 2035 car-engine regulation revision) have granted a continued pathway for internal combustion vehicles powered by climate-neutral synthetic fuels. As a result, infrastructure planning must adapt to include distributed biodiesel and biomethane production, hydrogen refuelling stations, and e-fuel supply chains alongside EV chargers. Recent reviews by Dua (2024) and Enrich-Prast and Eklund (2024) demonstrate that integrating hydrogen, biofuels, and e-fuels enhances system resilience, supports freight and long-haul mobility, and aligns with EU’s techno-economic policy goals [66,67]. Accordingly, we recommend that national and local planners incorporate a multi-fuel infrastructure perspective, ensuring that charging, gaseous fuel, and synthetic-fuel networks are developed in coordination to serve distinct market segments and to adapt to evolving regulatory conditions. A harmonized infrastructure strategy must reflect the heterogeneous nature of alternative fuel technologies across multiple transport segments. While electric vehicle (EV) charging networks are rapidly scaling in urban environments, hydrogen refuelling infrastructure remains limited to pilot corridors, and advanced biofuel distribution is regionally uneven. Each technology varies in terms of investment intensity, deployment speed, spatial accessibility, and integration with existing energy systems.

This study confirms that Poland’s transition to electric mobility is challenged not only by infrastructure density but also by systemic barriers, including grid dependence on coal and the limited rollout of renewable storage. While the scenario analysis suggests feasible growth in charging stations, full decarbonization will require synchronized investments in energy generation, distribution, and storage.

7. Conclusions

The objective of this article was to provide a comprehensive analysis of the development of green fuelling infrastructure in road transport, with particular attention to electric vehicle (EV) charging stations and the potential of biofuels and hydrogen. Based on statistical data and indicators such as the Infrastructure Accessibility Index (IAI) and Pearson correlation analysis, a significant relationship was observed between economic (GDP per capita) and energy (share of renewables) indicators and the level of EV infrastructure development. The findings indicate that countries with higher economic development and greater shares of renewable energy tend to have better-developed charging networks.

A scenario-based analysis for Poland estimated the required number of charging stations by 2030 under different assumptions of EV market growth. The study highlighted the need for significant investments in infrastructure, especially in urban areas and along major transport corridors, to meet the anticipated demand. Moreover, the study addressed the environmental challenges associated with the lifecycle of EVs, particularly the impact of battery production and disposal, emphasizing the importance of recycling and second-life applications.

The second part of the paper examined various generations of biofuels and alternative fuels (including bioethanol, biodiesel, HVO, biohydrogen, algae-based fuels, and solar-to-fuel systems), outlining their technological properties, environmental impact, limitations, and development potential. Special attention was paid to second- and third-generation biofuels, which do not compete with food production and can be integrated into circular economy models.

Key conclusions drawn from the study include the following: the development of EV charging infrastructure is closely linked to a country’s economic capacity and renewable energy policy; Poland must increase its share of renewable energy and upgrade its power grid to support the electrification of transport, particularly under high-adoption scenarios; investments in diverse alternative fuel technologies, including advanced biofuels and hydrogen, should complement electromobility, particularly in sectors like freight, maritime, and aviation; and a life-cycle perspective is essential to assessing the real environmental benefits of electric vehicles, including battery production, use, and end-of-life management.

This study underscores that the uneven development of green fuelling infrastructure, particularly in countries like Poland, reflects not only financial and logistical challenges, but also deeper systemic limitations. Despite projected growth in EV charging stations, a full-scale transition to electric mobility remains constrained by the current dependence on coal-based electricity, insufficient grid flexibility, and the underdevelopment of renewable energy storage systems. These structural barriers must be addressed in parallel with infrastructure expansion. Therefore, policy interventions should extend beyond vehicle and station incentives to include long-term investments in decarbonising the energy mix, enhancing storage technologies, and improving cross-sectoral coordination. Without such an integrated approach, the vision of zero-emission mobility risks being technologically feasible but practically unattainable in certain national contexts.

The green transformation of road transport is a multidimensional process requiring a synergistic approach across technologies, infrastructure, education, and policy. The analysis presented in this article offers a solid foundation for further planning and regulatory efforts that support a fair and effective decarbonization of the transport sector.