Renewable Energies as a Substitute for Fossil Fuel Resources in Poland


 BackgroundThe characteristic feature of modern energy sector in the EU is the development of environmentally friendly technologies based on renewable energy sources (RES). The use of alternative and RES contributes to resolving not only energy efficiency issues, but many of the environmental, economic and social problems. RES are also one of the priorities of the world's low carbon policy and reducing CO2 emissions into the atmosphere. Growing electrical energy consumption and increasing integration of RES in power systems have led to new challenges, thus it is required to investigate and properly analyze the impact of integrated RES on the power system as a substitute for fossil fuel resources.ResultsThe aim of the article is to show the possibilities of developing RES in Poland in the context of environmental protection, energy self-sufficiency and international obligations. The depletion of primary energy sources and the increase in emissions of greenhouse gases to the atmosphere forces undertaking certain activities, aimed at seeking substitutes for fossil fuels. According to the author’s analysis, RES are the best and safest substitutes for traditional energy resources such as fossil fuel.ConclusionsThe author examines electricity production mix in EU counties and compares it to Polish energy sector. Taking into consideration the transmission network density in Poland, while energy sector changes its structure and expands, the mix of technologies deployed to produce electricity determines the associated burden on transmission networks. Polish energy sector development in the context of modernization of transmission grid provides an opportunity for investors to prepare the energy system for increasing the share of renewable energy sources. In the process of implementing the appropriate solution, the experiences of other countries that have significantly increased the share of renewable energy in the past could be used. This article presents the main areas of action that may facilitate the further integration of different energy sources in the specific context of Poland's changing energy system. Not all integration options will be important for Poland at the same time.

This paper uses scienti c studies published mainly in Polish and English languages as well as statistic data from Ministry of Energy in Poland, Eurostat databases, polish statistics o ce, etc. The publications authored by Yankelovich D., Wojnowski J., Tomaszewski K., Nyman J., Maj R. are of the utmost importance for the scienti c analysis of the development of Polish renewable energy sector, taking into account European conditions and experiences, directly and indirectly related to the development of energy sector.
In the last twenty years, the interest in environmental protection issues, including the development of renewable energy sources, has increased in scienti c literature in Poland. This is so not only because of the obligations towards the signed EU strategies and constantly increasing demand for energy, but also because of the development of the awareness of the society and entrepreneurs who see future business potential in this eld. Furthermore, it is worth highlighting that the problems of international energy security in the 21st century have been given important attention in different scienti c papers.
Numerous articles and scienti c publications re ect the problem of energy security, energy dependence of the EU and Poland on energy supplies from abroad, mostly from Russia. In Poland, issues related to energy security should be treated as an important element of national security. This topic is important and attractive in terms of research, therefore there are a large number of sources, which, however, are limited to a small number of monographs, and the dominant role is played by analyzes, articles and chapters in collective works devoted to issues in the eld of security theory. The authors analyze this issue from the perspective of political science, especially within the framework of placing Poland's energy policy in the European context, but also in the technical and economic context, using an interdisciplinary approach necessary in the presentation of the state's energy balance. They also take into account aspects of the theoretical analysis of the concept of energy security. There are also discussions aimed at ensuring the country's energy security, or at least reducing the risks associated with it due to the geographical location, the need to increase Poland's energy self-su ciency in terms of the demand for electricity produced from renewable sources and fossil fuels.
However, there are no comprehensive research treating renewable energy sources as an element of permanent sustainable development and their reference to the national and European scale, which is a response to the growing ecological and climate challenges of the modern Europe in the context of the density of transmission networks and power grid. This paper uses the method of diagnostic survey, which understood by T. Pilch and T. Bauman (Pilch, Bauman 2001) as a way of gathering knowledge about structural and functional attributes as well as about the dynamics of social phenomena, opinions and views of selected communities, the intensi cation and directions of development of speci c phenomena, based on a selected group in which a given phenomenon occurs. Apanowicz J. (Apanowicz 2003) notes, that the diagnostic survey method is a scienti c undertaking that consists in the statistical collection of facts and information about structural and functional phenomena and the dynamics of their development. This method enables a statistical description and helps to explain certain mass phenomena. According to Łobocki M. (Łobocki 2000), the survey method is understood as a research method whose primary function is to collect information about problems of interest to the researcher.
Multidimensional market relations: energy producers -transmission networks -nal recipients, in which renewable energy development issues take a special place, contributed to the topic and prompted the formulation of this paper goals. Therefore, the main aim of the article was to assess the current state of development of renewable energy sources as a substitute of traditional sources of electricity on the background of the EU energy policy and the development of transmission networks.
After collecting and processing the source materials, it was processed using the following research methods: analysis, synthesis, confrontation and criticism of the source materials, which forms the foundations of the scienti c development of the undertaken topic, exposing the essence, purpose and original tasks of the undertaken research.

Discussion
Searching for new renewable energy sources (RES) solutions began in the early 1970s as a result of the 1973 oil crisis. The research took nearly 20 years, and the outcomes became noticeable only in the 1990s. The startup period in the implementation of new technologies extended approximately over two decades (Kwinta 2014).
The environmental protection measures and the battle against climate change de nitely involve funds being transferred across the globe. According to Bloomberg New Energy Finance (BloombergNEF 2020), the investments in the renewable energy sector reached USD 333.6 billion in 2019 ( g. 1). According to Bloomberg data, the peak investment ow in Europe ended in 2011, reaching USD 134 billion (BloombergNEF 2020).
Nowadays, Asia-Paci c region is the leader of RES investments in the world as the economies around the world are still indisputably highly dependent on energy sources. The availability and cost of energy carriers (petroleum, coal, natural gas) are determinant for the pace of economic development at a country level. Therefore, it is of utmost importance for most countries to be able to secure the supply of energy carriers for their economies and to make sure end customers have access to energy. For example, according to recent research (Yankelovich 2006; Ostry 2010; Nyman 2018) on the US foreign policy, nearly 90% of Americans consider energy security to be a priority. It is therefore no surprise that all countries pay much attention to energy diversity and energy security.
It is crucial to ensure energy security for every country, which means diversi cation of energy supply, i.e. the use of a broad range of sources of energy raw materials and various types of energy, and to diversify suppliers and transport paths and mechanisms. A system based on ten to twenty large power plants is more vulnerable to sabotage than a one based on ten to twenty thousand dispersed small-to-medium capacity power stations. The risk related to the EU's energy dependence may be reduced by establishing reliable partnerships with suppliers, transit countries and customers. Figure 2 shows the diversi cation of electricity sources in EU countries grouped by energy source.
As shown in Figure 2, Poland is the EU's fourth largest consumer of fossil fuels (mainly coal) used for electricity generation. The Polish energy sector has always been based on coal and lignite, and therefore the largest power generation units were located near coal and lignite mines.
According to the Energy Market Agency and to PSE S.A. data, the share of coal in the energy source mix decreased from 62% in 1996 to 49,27 % in 2019 (2020b). However, coal remains the main source of electricity in Poland, as shown in Figure 3.
According to the "Polish energy policy to 2030" and "Program for the hard coal mining sector in Poland" coal will remain the basic raw material for the electric power sector (Ministry of Economy 2009; Ministry of Energy 2018), even though the extraction capacity declines and the mines lack funds to access new deposits. Also, the market offers large quantities of cheap imported coal. Combined with the poor performance and underinvestment of Polish mines, this results in a slowdown affecting the electricity sector (Wroński 2015).
The energy networks are underdeveloped, especially in the current situation of abovementioned conditions. The reason for this is the fact that the transmission and distribution networks were neither expanded nor upgraded since the 1970s and the network infrastructure ( Figure 5) is not aligned with the changing location and structure of electricity demand and production. All abovementioned circumstances results, for instance, in blocking the access to electricity from wind and biogas power plants and developing the distributed generation. As a consequence, according to some forecasts, by 2030, ca. 60% of electricity will be produced from coal while the share of RES will be ca. 20%, as shown in When comparing the density of electricity grids between Poland and other European countries (Figure 7), the difference is clearly noticeable. As mentioned earlier, Poland has one of the Europe's lowest infrastructure densities of highest-voltage transmission lines.
Especially during summer period, electricity demand largely exceeds the average level, particularly in major agglomerations. Many networks in these areas have already reached their operational limits and must be extended and upgraded (Wasiuta 2014). Therefore, rm conclusions can be drawn regarding the extent of required investment projects in Poland. In Polish economy, the demand for hard coal is partially ful lled with imports, and that trend is forecasted to continue. In 2017, coal imports into Poland was 13,3 million tons which is 18% of total consumption. By the end of 2019, 16,7 million tons of coal were imported into Poland, which is 24% of total consumption (Statistics Poland (GUS) 2020).
In Poland, steam coal accounted for most of the imports. The largest quantities (61% of total imports) were imported into Poland from Russia, followed by Australia with 19.2% (although it was coking coal only); 8.6% of total coal imports originated from the USA and Columbia (EUROSTAT 2020b).
The problem of lignite extraction is also discussed intensively, mainly with the environmentalist community, because it has a strong environmental impact (Wojnowski 2002). For the energy sector and the coke industry, it would be impossible to switch exclusively to Polish raw materials because some types of coal are not extracted in Poland (Wasiuta 2014). Compared to neighboring countries, Poland has relatively large coal resources, documented natural gas reserves, shale gas, Europe's largest geothermal reservoirs. Among the non-biomass renewable options, wind power has the largest potential in Poland.
The main challenges to its development are the limited number of locations with high wind speed. Offshore offers better wind speed than onshore, but its costs are twice as high (Waydel 2008;Gielen et al. 2015).
Nuclear power plants are a controversial source of energy for the society and a potential target for hackers, and therefore involve the issues of national security. Nevertheless, it can be pointed out the low carbon emission aspect of nuclear energy (Johnson 2009). Having the above in mind, according to different calculations, wind energy, for instance offshore wind energy at the Baltic sea, could be a substitute for nuclear energy in Poland (2012; Kowalczyk 2019). In this context, the diversi cation of energy sources is a fundamental aspect of managing the risks to secure supplies of energy raw materials to any country. Renewable energy sources could play a major role in this process. The production of electricity from renewable sources, and especially distributed generation production cannot be perturbed by foreign governments or other national or international organizations; this is an essential aspect for the country's energy security.
Though more expensive, cogeneration is more environmentally friendly and consists in the simultaneous production of electricity and heat used in industrial processes, building heating and water heating. It results in saving conventional sources and reducing carbon emissions, as promoted under the relevant EU Directive (European Parliament 2012). Cogeneration is crucial for the national energy security. The European Union pays particular attention to promoting this technology by emphasizing not only its energy e ciency but also the ability to considerably reduce the emissions of carbon dioxide and other harmful chemicals. While this technology attracts interest from the coal and gas industries, it may also be combined with renewable energy sources. Undoubtedly, such a solution contributes to reducing the use of conventional fuel in electricity and heat production processes.
The greater use of primary energy contained in fuel in the simultaneous production of electricity and heat contributes to improvements in energy e ciency. This is the key advantage of this system: energy e ciency may be up to 30% higher compared to separate generation of both types of energy in condensing power plants (electricity) and boiler stations (heat). Cogeneration plants provide heat and power 50 -70% more e ciently than traditional facilities. Observation of technological processes shows that a cogeneration system uses 100 fuel units to produce 40 units of electricity and 50 units of heat whereas a total of 170 fuel units are required to produce the same amounts of energy in separate processes (Buczyńska 2015;Schleup 2008).
However, real bene ts can be attained through the use of renewable energy sources. If used instead of conventional fuels, they contribute to a further reduction in carbon emissions. In cogeneration, renewable energy sources mainly mean the use of biomass. Ingredients used to cogenerate heat and electricity include: farm waste, waste food, plants and waste wood. In broad terms, biomass also means biogas which is produced with the use of manure or in waste treatment plants. The greatest shares of biomass used in cogeneration systems are reported in Sweden and New Zealand, i.e. countries with the largest forestry and wood industries (Buczyńska 2015). In accordance with these assumptions, the obligation to purchase renewable energy was introduced.
The adoption of the Act on Renewable Energy Sources (Sejm of the Republic of Poland 2015b) was followed by many changes. For the rst time in Poland, feed-in tariffs were introduced which specify the principles for the sale of energy by the smallest RES micro-installations to the grid.
Because of the fact, that the support mechanism for high-e ciency cogeneration expired at the end of 2018, the Ministry of Energy prepared a draft Act on Promoting Electricity from High-E ciency Cogeneration (2018) providing for a new support mechanism for the producers of energy from cogeneration installations. By the end of 2019 the law was adopted and entered into force (Sejm of the Republic of Poland 2019). The introduction and implementation of these changes is an important element in the ght against high levels of pollutants and greenhouse gases in Poland. In addition to cogeneration, tri-generation becomes increasingly important, especially in Germany (because of the availability of the technology). This means using the same technological process to generate heat, electricity and cooling energy in order to reduce the amount and cost of primary energy required to produce each of these energies separately (Gailfuß 2019).
Heat, cooling energy and electricity are three totally different products subject to different laws. While the market for heat and cooling energy is of a purely local nature, electric power is sold across a wide territory (on a countrywide and Union-wide basis). Ecological arguments and the strategic importance of cogeneration and tri-generation, mainly due to improvements in the e ciency of primary fuel consumption through the use of heat, are the reasons why efforts are being made to introduce stronger economic incentives and legal frameworks supporting the use of these solutions. The cogeneration policy results from the EU climate policy. To meet the objective of reduced carbon emissions, it is necessary to considerably reduce heating-related emissions.
Self-su ciency means not only secure supplies of energy to end customers from external and internal suppliers but also the internal operational security of the entire energy sector. In Poland, it is threatened by many factors, such as miners' strikes, the deplorable condition of transmission networks, as re ected by numerous network failures and measures taken by monopolists who do offer certain products to end customers but charge extremely high prices. These threats may be quali ed as socio-political, technical and economic aspects. However, the customer does not care about the reasons behind a disruption in energy or fuel supply. Some countries, e.g. the US, Italy or Japan, are not energy self-su cient but feel secure. This is because their national energy policies address various dimensions: e ciency (in Japan), diversi cation (Italy and US) and adequate foreign policy, especially alliances (in Japan and US). Equating energy security with self-su ciency may result in an attempt to build a country which does not need any external relationships. This would be unviable, as illustrated by the example of North Korea (2007). However, the above does not mean that Poland should refrain from seeking a greater degree of self-su ciency in industries which rely on other countries, i.e. the gas and liquid fuels industries.
The development of renewable energy sources is among the key objectives of the Polish energy policy.
The draft "Energy policy for Poland to 2050" (Ministry of Energy 2015a) developed by the Ministry of Economy includes a long-term development strategy for the energy sector, a forecast of fuel and energy demand and an implementation program. Also, it clearly indicates the development of RES to be a strategic objective (Ministry of Energy 2015b). The document de nes priority lines of action, such as: improvements in energy e ciency; increased security of fuel and energy supply; diversi cation of electricity production (through the introduction of nuclear energy); greater use of renewable energy sources, including biofuel; development of competitive markets for fuel and energy; and reduced environmental impact of the energy sector. The Minister of Economy monitors the ongoing progress in policy implementation. Also, an interministerial team in charge of national raw material policy (Poland 2012) has been in place since 2016. The key role of RES in the development of the Polish energy sector is also re ected by the adoption of the long awaited Act on Renewable Energy Sources (Sejm of the Republic of Poland 2015a).
The key lines of development for the energy policy are as follows (Ministry of Economy 2009): improvements in energy e ciency; increased security of fuel and energy supply; diversi cation of the electricity production mix through the introduction of nuclear energy; extended use of renewable energy sources, including biofuel; development of competitive markets for fuel and energy; reduced environmental impact of the energy sector. The de ned energy policy orientations are largely interdependent. The improvements in energy e ciency reduce the increase in demand for fuel and energy. This contributes to energy security by making the country less dependent on imports while also helping reduce emissions and the resulting environmental impact of the energy sector. Similar effects can be achieved by promoting a greater use of renewable energy sources, including biofuel, clean coal technologies and nuclear energy.
To comply with European Union obligations, Poland as well as all EU countries, is required to reach the share of energy from renewable energy sources in EU's gross nal consumption of energy in 2030 which is 32% (European Parliament 2018). Every country will also be committed to a greater integration of renewable energy sources into the energy system, for increasing exibility of the energy system and maintaining grid stability, developing transmission and distribution grid infrastructure and intelligent networks. It should be also noted, that initially much was expected from the use of biofuels and bioliquids, including a reduction in transport carbon emissions and freeing the country from dependence on fossil fuel supplies from abroad. However, in reality, the situation proved to be much more complicated. The European Union issued two Directives which require the member states to attain speci c levels of biofuel use in transport. For the calculation of a Member State's gross nal consumption of energy from renewable energy sources and the minimum share of biofuels and bioliquids consumed in transport, where produced from food and feed crops, shall be no more than one percentage point higher than the share of such fuels in the nal consumption of energy in the road and rail transport sectors in 2020 in that Member State, with a maximum 7% of nal consumption of energy in the road and rail transport sectors. As a consequence of this policy, large areas under existing crops started to be converted to biofuel feedstock production. At the same time, to meet the growing demand for food, it was necessary to establish new agricultural areas. This is done through deforestation and destruction of peatland and other valuable habitats which naturally store carbon and reduce atmospheric carbon According to assumptions of the "Polish energy policy to 2030," support mechanisms for RES development in Poland need to be strengthened; improvements should be made to the investment climate; new, more effective economic instruments should be deployed to provide a momentum for RES investments and for the production of RES-based technologies while also maximizing the absorption of European funds, mainly under the Regional Operational Programs, Rural Development Program and the Infrastructure and Environment Operational Program, allocated to such projects as: production of renewable energies together with the connection to the distribution/transmission network (hydropower, wind, solar, geothermal, biogas and biomass energy); construction and reconstruction of networks enabling the connection of renewable electricity to the National Electricity System; construction of installations for biofuel and its components.
Even though the relevant act was adopted, the development of RES in Poland continues to face many problems. The uncertainty surrounding the regulations and the absence of support for the development of a dispersed RES system are the main barriers to the development of this sector in Poland. According to the "Polish renewable energy machinery industry: updated business directory and assessment of development opportunities for the industry in the 2020 and 2030 time horizon," (Wiśniewski et al. 2016) a report by the Institute for Renewable Energy, the absence of a consistent support policy for the Polish RES industry may result in halting its development and losing measurable bene ts. It has already become apparent that some industries of this sector face an uncertain future. For instance, solar energy companies are doing somewhat better but without adequate incentives from the government they, too, may stop developing. Currently, as many as 33,800 people are employed in the RES industry. According to the "energy revolution" (2013)  According to experts from the Institute for Renewable Energy, the Polish industry of solar energy equipment alone may contribute a total of PLN 18.5 billion to the budget in 2015-2030. However, this cannot be done without a stable legislation and a long-term policy which provide support for dispersed RES systems .
A stable and socially equitable support system is a necessary condition for the development of the Polish RES sector, especially including the most promising small and micro-installation segment. Feed-in tariffs are the most effective support instrument for the development of the RES sub-sector specialized in the manufacture of power generation equipment. The bene ts of this system are the predictability and simplicity of support. It is also crucial that support has to be provided mostly for dispersed investments in small and micro-sources to encourage the development of local companies and prosumers. In order for renewable energy companies to develop, the equipment manufacturing sector must be included in o cial statistics on the RES sector (which currently are not kept) . The amendment to the RES Act extends the support for RES development by combining feed-in tariffs with a system of rebates (Article 4 of the RES Act (Sejm of the Republic of Poland 2015b)) which enables cashless settlement of payments for electricity used by prosumers and produced in a micro-installation.
So far, the Polish RES industry has the longest track record in the production of solar collectors, biomass boilers and heat pumps. Each year in Poland, specialized companies sell and install equipment worth PLN 2 billion. A steep decline in multiannual support programs for RES-based heat production and the promotion of coal as a local fuel are barriers to the development of these traditionally strongest companies of the Polish RES industry and make it impossible to offset losses incurred domestically with exports (Sejm of the Republic of Poland 2015b).
By leveraging market mechanisms, the Energy E ciency Act introduces a series of measures, including the system of energy performance certi cates -so called "white certi cates", which should drive measurable energy savings in three areas: increased energy savings for end customers; increased energy savings in personal equipment; and reduced electricity, heat and natural gas losses across the industry and in distribution networks. B2C energy suppliers are required to receive and submit "white certi cates" for redemption to the President of the Energy Regulatory O ce. Otherwise, they must pay a compensation fee. Electricity, natural gas and heat suppliers are required to obtain a speci c number of certi cates depending on the amount of energy sold.
Although the households keep improving their energy e ciency ratios, energy demand in this sector is estimated to grow until 2030. While total energy consumption will increase only slightly (by ca. 5%), the increase in the consumption of one of its components (electricity) will grow by as much as 50%. Electricity production uses the greatest amounts of primary energy, and therefore electricity savings are potentially most bene cial to the environment. Since early 2000s, Poland has witnessed tremendous improvements in energy e ciency. Indeed, the energy intensity of Gross Domestic Product decreased by nearly one third. However, energy e ciency of the Polish economy is three times lower compared to the most developed European countries and approximately two times lower than the EU average level. Also, primary energy use per capita in Poland is almost 40% lower than in the"old 15" EU countries. This suggests there is a great potential for energy savings in Poland, which is a characteristic of economies experiencing rapid growth (Ministerstwo Infrastruktury i Rozwoju 2014).
Households use ca. 20% of electricity consumed in Poland (Maj 2015), and have the greatest impact on consumption growth rates. The potential for savings seems considerable, yet not adequately used. Therefore, the question could be explored whether households should be provided with greater support in the area of electricity savings.

Conclusions
The development of low-carbon energies which is an economically strategic sector of science, engineering and technology, depends on signi cant improvements to its development conditions. With reference to the essential objective of the European Union Directive on renewable and low-carbon forms of energy generation, it may be concluded that no single organizational solution and no single technology exists that could meet the demands and expectations of all parties. Optimum solutions must be sought in speci c locations (using primarily combined heat and power) and speci c macroeconomic and regional environments. Ensuring the conditions for a contribution to the development of renewable energies in Poland is a challenge to the government. The energy sector should evolve in a direction consistent with measures taken by the European Union and with initiatives taken by local authorities.
However, despite the great opportunities behind the use of renewable energies, their average share in the general energy mix of European Union countries is expected to be only 32% by 2030. Perhaps it will rise to 50% by 2050. Therefore, while having no other option than to continue relying on coal, oil and gas and nuclear energy in some countries, European Union must be aware of the consequences of the continued use of these energy carriers. An increased use of renewable energies should neither make EU less vigilant to energy security nor release it from responsibility for future generations.

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Competing interests -Not applicable.   Total length of 220 kV and 400 kV transmission lines per 1000 m2 of national territory Source: (Stankowska 2009)