{"id":28,"date":"2018-12-14T10:01:25","date_gmt":"2018-12-14T10:01:25","guid":{"rendered":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/?post_type=chapter&#038;p=28"},"modified":"2024-03-12T14:36:44","modified_gmt":"2024-03-12T14:36:44","slug":"lecture-1-system","status":"publish","type":"chapter","link":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/chapter\/lecture-1-system\/","title":{"raw":"Electric Power System","rendered":"Electric Power System"},"content":{"raw":"<h1>Definition of EPS<\/h1>\r\n<p style=\"text-align: justify\">A <strong>system<\/strong> is a set of devices interconnected to fulfill previously specified function.<\/p>\r\n<p style=\"text-align: justify\">An <strong>energy system<\/strong> is defined as all components related to the production, conversion, delivery, and use of energy. The system structure, so a system itself is formally determined by a\u00a0 pair of ordered sets <em>S = &lt;U, K&gt;<\/em>, where <em>U<\/em> \u2013 a set of devices and <em>K<\/em> \u2013 a set of relations of interconnections of these devices, it is a set of configurations.<\/p>\r\nEnergy systems are divided according to energy carriers on:\r\n<ul>\r\n \t<li>electric power systems,<\/li>\r\n \t<li>thermal systems,<\/li>\r\n \t<li>gas-energy systems,<\/li>\r\n \t<li>systems of solid fuel supply<\/li>\r\n \t<li>systems of liquid fuel supply.<\/li>\r\n<\/ul>\r\nAn\u00a0<strong>electric power system\u00a0<\/strong>is a network of electrical components deployed to supply, transfer, and use electric power.\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Basic elements of electric power system (<strong>EPS<\/strong>) are:<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<ul>\r\n \t<li>generating units (power plants),<\/li>\r\n \t<li>transmission network,<\/li>\r\n \t<li>distribution network.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<h1>Main components of EPS<\/h1>\r\n<p style=\"text-align: justify\">A <strong>generating unit<\/strong> is created by a separated set of power plants\u2019 devices, which form independent technologic series of electric energy generation and which can generate electric energy by itself. Generating units are divided into traditional: coal, nuclear, gas, liquid fuels, and, recently quickly developing units based on renewable energy sources: hydro, wind, biomass and others.<\/p>\r\n<img class=\"size-full wp-image-61 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/img_5c138aaa438af.png\" alt=\"\" \/>\r\n<p style=\"text-align: justify\">An <strong>electric power network<\/strong> is a set of cooperating electric power lines and substations used for transmission, transformation and distribution of electric energy on specified area. Lines are divided into overhead with bare and insulated conductors and into cables. The following elements are met in substations: transformers, reactors (choking coils), capacitors, bus bars, switches and others.<\/p>\r\n&nbsp;\r\n<div style=\"text-align: justify\"><strong>Transmission networks<\/strong> belong to transmission electric power system which encompasses lines and substations of the highest voltages. They serve for the transmission of electrical energy over long distances. In Poland these are lines of voltages over 110 kV (220 kV and 400 kV). Voltage 400 kV is treated as evolutional.<\/div>\r\n<div><img class=\"size-full wp-image-62 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/img_5c138ab6e50da.png\" alt=\"\" \/><\/div>\r\n<div style=\"text-align: justify\"><strong>Distribution networks<\/strong> belong to distribution power systems which contain networks and power substations of low voltages, medium voltages and high voltages. They are used for distribution of electric energy between customers. In Poland these are low voltage networks (0.4 kV, 0.66 kV), medium voltage networks (6 kV, 10 kV, 15 kV, 20 kV, 30 kV) and high voltage networks \u2013 110 kV.<\/div>\r\n<img class=\"size-full wp-image-63 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/img_5c138ace5b32c.png\" alt=\"\" \/>\r\n\r\n&nbsp;\r\n<h1>Characteristic features of EPS<\/h1>\r\n<p style=\"text-align: justify\">The <strong>characteristic feature of EPS<\/strong> is that it <strong>covers large territory<\/strong> because usually it is the whole country.\r\nLong distances in case of large countries like Russia, Canada, USA, Australia, Brazil force to intensive research investigations in the area of electrical energy transmission technology on long distances (especially high voltage direct current transmission lines - HVDC).<\/p>\r\nWith current initiatives on smart grid and sustainable energy, <strong>distributed generations (DGs)<\/strong> and <strong>renewable energy sources (RES)<\/strong>, characterized by relatively small powers are going to play vital role in the emerging <strong>small<\/strong>, <strong>independent<\/strong>, <strong>local electrical power systems<\/strong>.\r\n<p id=\"RvYuehK\">From cybernetics point of view EPS is a huge system constituting multi-input and multi-output arrangement, relatively separated, dissipative, weakly self-adjustable and additionally controlled by the staff.<\/p>\r\n\r\n\r\n[caption id=\"attachment_77\" align=\"aligncenter\" width=\"648\"]<img class=\"wp-image-77 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c6157f66038a.png\" alt=\"\" width=\"648\" height=\"385\" \/> Fig. 1.1 Cybernetical approach to EPS[\/caption]\r\n\r\nThe extension\/development of EPS is directly connected with other branches of economy for which EPS serves and on which its development and existence depends. These are industry of fuel mining and reprocessing, other electric power systems, hydro economy of the country, machine-building industry and scientific background, infrastructure of the country, environment, etc.\r\n\r\n&nbsp;\r\n<div class=\"textbox shaded\">\r\n\r\nThe system is characterized by many parameters. The most important of them are the following:\r\n<ul>\r\n \t<li>peak power demanded by customers,<\/li>\r\n \t<li>annual production of electric energy,<\/li>\r\n \t<li>power installed in generating units,<\/li>\r\n \t<li>power of the largest generating unit,<\/li>\r\n \t<li>the highest nominal voltage of the transmission network,<\/li>\r\n \t<li>the longest distances of power flow,<\/li>\r\n \t<li>power structure,<\/li>\r\n \t<li>network structure.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<strong>Definitions of important parameters:<\/strong>\r\n\r\n<strong>Installed power <\/strong>of domestic power plants, it is the sum of nominal powers of all generating units (eg Poland at the end of 2002 was 34715MW).\r\n<strong>Maximum output capacity<\/strong> of commercial power plants in the system, it is the sum of the continuous powers of all generating units in the system, produced by thermal generators in the continuous way in the time of at least 15 hours, and by water generators in the time of at least 5 hours, at nominal conditions of work acknowledged by tests. (eg Poland it was 31887 MW in 2004)\r\n\r\n<strong>Available capacity<\/strong> of the domestic power plants it is maximum output capacity reduced by planned outages (maintenance), periodical losses, exploitation losses and others (eg in Poland in 2004 it was 26865 MW).\r\n\r\n<strong>Maximum annual demand for power<\/strong> it is power measured on the lines leading the current out from power stations (eg in Poland in 2004 it was on December 23 at 17.00 and it was 23108 MW) .\r\n\r\n&nbsp;\r\n\r\nElectric power system, <strong>as distinct from other economy systems<\/strong>, realizes tasks connected with the production, transmission and distribution of the product with immediate supply on any request of the client. It is characterized by the<strong> lack of possibility to store the product<\/strong>. All the production is consumed immediately. Thus the customers have the influence on production scale. It definitely determines current control of EPS operation.\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n<h1>Energy storage<\/h1>\r\nElectric energy cannot be directly stored, but some other energy carriers may be used to do it. The only one, commonly used way of electrical energy storage, is a pumped power station, in which during hours of small load the water is pumped from the lower reservoir to the upper one.\r\n\r\n[caption id=\"attachment_76\" align=\"aligncenter\" width=\"402\"]<img class=\"wp-image-76 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c6156e27830f.png\" alt=\"\" width=\"402\" height=\"222\" \/> Fig. 1.2 General idea of pumped hydro power station. Source: www.energy-storage.news, EnergyAustralia[\/caption]\r\n\r\nLast decade is a period of intense development of various types of energy storage other than pumped-storage hydroelectricity. Leading technologies are:\r\n<span style=\"text-decoration: underline\">Thermal power stations:<\/span>\r\n<ul>\r\n \t<li>Molten salt<\/li>\r\n<\/ul>\r\n<span style=\"text-decoration: underline\">Electrochemical:<\/span>\r\n<ul>\r\n \t<li>Lithium batteries,<\/li>\r\n \t<li>Sodium-sulfur batteries (NaS),<\/li>\r\n \t<li>Lead-acid batteries,<\/li>\r\n \t<li>Nickel batteries.<\/li>\r\n<\/ul>\r\n<span style=\"text-decoration: underline\">Electromechanical:<\/span>\r\n<ul>\r\n \t<li>Flywheels,<\/li>\r\n \t<li>Compressed-Air Energy Storage,<\/li>\r\n<\/ul>\r\n<span style=\"text-decoration: underline\">Chemical:<\/span>\r\n<ul>\r\n \t<li>Hydrogen storage.<\/li>\r\n<\/ul>\r\n[caption id=\"attachment_79\" align=\"aligncenter\" width=\"810\"]<img class=\"wp-image-79 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c615ab4e97a2.png\" alt=\"\" width=\"810\" height=\"400\" \/> Fig. 1.3 Technology maturity of storage. Source: Christiansen, C. and Murray, B. 2015. AECOM Energy Storage Study.[\/caption]\r\n<h1>Load profile<\/h1>\r\n<strong>Power structure<\/strong> is characterized by the way of covering system loads so it contains data about generating units. The curve of total system load by the powers demanded during 24 hours P(t) has the influence on the power structure.\r\n\r\n<img class=\"wp-image-731 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/06\/img_5cfe47414151d.png\" alt=\"\" width=\"635\" height=\"435\" \/>\r\n\r\n&nbsp;\r\n\r\n<strong>Basic load<\/strong> is covered by steam power plants characterized by small per-unit fuel costs, nuclear power plants and thermal-electric power stations. <strong>Midload<\/strong> power is covered by older thermal power stations and renewable sources.\r\nCovering of <strong>peak load<\/strong> should be guaranteed by hydro generating units, gas units and liquid fuel units.\r\n\r\n[caption id=\"attachment_82\" align=\"aligncenter\" width=\"440\"]<img class=\"wp-image-82 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c615f2a8017f.png\" alt=\"\" width=\"440\" height=\"307\" \/> Fig. 1.4 Generation power structure and demand. Source: www.pse.pl[\/caption]\r\n<h1>System structure<\/h1>\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">EPS can be divided on three hierarchical levels:<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<ul>\r\n \t<li>generation level,<\/li>\r\n \t<li>transmission level,<\/li>\r\n \t<li>distribution level.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n\r\n[caption id=\"attachment_83\" align=\"aligncenter\" width=\"543\"]<img class=\"wp-image-83 \" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61601c1846a.png\" alt=\"\" width=\"543\" height=\"722\" \/> Fig. 1.5 EPS levels and elements.[\/caption]\r\n\r\n&nbsp;\r\n\r\nThe <strong>level of generation<\/strong> is created by big system power stations which <strong>generators<\/strong> are connected to <strong>HV transmission network<\/strong> (400 kV, 220 kV) and to HV distribution network (110kV), through step-up transformers (the voltage on generators\u2019 terminals is about 20 kV - to small to send the power on long distances).\r\n\r\nThe <strong>level of transmission<\/strong> is created by <strong>lines and electric power substations 750 kV, 400 kV and 220 kV<\/strong>.\r\nThe different levels of voltages are coupled by\u00a0 transformers (the voltage ratio &gt; 2) or by auto-transformers (ratio \u2264 2). Reactive power compensation of opposite sign is used in HV transmission network because of its high reactive power generation.\u00a0In EHV\/110kV sub-stations capacitor banks for reactive power compensation are used on 110 kV side.\r\n\r\nThe <strong>level of distribution<\/strong> is created by <strong>networks and substations of medium and low voltages<\/strong>.\r\nCapacitor banks for reactive power compensation are used in:\r\n<ul>\r\n \t<li>substations 110kV\/MV on the medium voltage side,<\/li>\r\n \t<li>MV and LV networks.<\/li>\r\n<\/ul>\r\nIndustrial customers are supplied directly from MV network and household customers are supplied from LV network.\r\n\r\n&nbsp;\r\n\r\nElectric power systems of different countries are often connected together and such systems are called integrated systems. These systems are organizationally independent but, in reality, they create one electric power grid.\u00a043 TSOs from 36 countries are members of ENTSO-E (the European Network of Transmission System Operators for Electricity).\r\n\r\n[caption id=\"attachment_89\" align=\"aligncenter\" width=\"448\"]<img class=\"wp-image-89 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c6161ce4c291.png\" alt=\"\" width=\"448\" height=\"343\" \/> Fig. 1.6 ENTSOE countries . Source: www.entsoe.eu[\/caption]\r\n<h1>Environmental pollution<\/h1>\r\nThe <strong>generation, transmission<\/strong> and <strong>distribution<\/strong> of electric energy cause more and more <strong>environmental pollution<\/strong>.\r\n<div class=\"textbox shaded\">\r\n\r\nMain but not only one cause of pollution is burning of organic fuels, which is accompanied by:\r\n<ul>\r\n \t<li>emission of : SO2, NOx, dust, CO2, CO and heat to the atmosphere,<\/li>\r\n \t<li>thermal pollution (heating) and chemical pollution of waters,<\/li>\r\n \t<li>devastation of the area by ash dumps.<\/li>\r\n<\/ul>\r\n<\/div>\r\n&nbsp;\r\n\r\nAdditionally the following things are connected with electrical power engineering:\r\n<ul>\r\n \t<li>noise pollution,<\/li>\r\n \t<li>electrical power engineering disturbances,<\/li>\r\n \t<li>stray currents in the earth,<\/li>\r\n \t<li>enlarged corrosion,<\/li>\r\n \t<li>climatic changes,<\/li>\r\n \t<li>wood cutting for electrical lines, fuel transport and others.<\/li>\r\n<\/ul>\r\n<div>Nuclear power plants may cause danger of radioactive pollution of atmosphere and waters. <strong>All\u00a0 parts of the nuclear fuel\u00a0 cycle produce some radioactive waste<\/strong> and the relatively modest cost of managing and disposing of this is part of the electricity cost.<\/div>\r\n<div>European Union and universal standards (Kyoto protocol) request sharp requirements on environmental protection. It is tied with meaningful financial involvement which has to be used for this goal.<\/div>\r\nThe main objective in managing and disposing of radioactive (or other) waste is to protect people\u00a0 and\u00a0 the\u00a0 environment.\u00a0 This\u00a0 means\u00a0 isolating\u00a0 or\u00a0 diluting\u00a0 the\u00a0 waste\u00a0 so\u00a0 that\u00a0 the\u00a0 rate\u00a0 or concentration\u00a0 of\u00a0 any\u00a0 radionuclides\u00a0 returned\u00a0 to\u00a0 the\u00a0 biosphere\u00a0 is\u00a0 harmless.\u00a0 To\u00a0 achieve\u00a0 this, <strong>practically all radioactive wastes are contained and managed<\/strong>\u00a0 \u2013 some clearly need deep and permanent burial. Many long-term waste management options have been\u00a0 investigated\u00a0 worldwide\u00a0 which\u00a0 seek\u00a0 to\u00a0 provide\u00a0 publicly\u00a0 acceptable,\u00a0 safe\u00a0 and environmentally sound solutions to the management of radioactive waste.\r\n<h1>Basic parameters<\/h1>\r\nThe work effectiveness of electricity receivers, fed from the system, depends on parameters of energy supplied from the system.\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Basic parameters of electrical energy are following:<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<ul>\r\n \t<li>frequency,<\/li>\r\n \t<li>voltage phase symmetry,<\/li>\r\n \t<li>the content of non-linear distortions in voltage curve,<\/li>\r\n \t<li>continuity of energy supply.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n&nbsp;\r\n\r\n[caption id=\"attachment_97\" align=\"aligncenter\" width=\"373\"]<img class=\"wp-image-97 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c616f8d02a4c.png\" alt=\"\" width=\"373\" height=\"278\" \/> Fig. 1.7 Three phase voltage.[\/caption]\r\n\r\nThe <strong>most important parameter<\/strong>, determining the operation of EPS \u2013 <strong>frequency<\/strong> \u2013 depends on the active power margin in generating units and it depends on the operation of frequency automatic control systems in EPS.\r\n\r\nProper <strong>voltage levels<\/strong> are results of reactive power reserves in sources of this power and they depend on the operation of voltage automatic regulation in EPS.\r\n\r\nThe <strong>phase symmetry<\/strong> depends on EPS elements\u2019 symmetry and on distribution on individual phases of single-phase receivers.\r\n\r\nThe <strong>shape of voltage curve<\/strong>, not being sinusoidal, results from actual continuous rise of the share of non-linear receivers in EPS. These receivers generate higher current harmonics.\r\n\r\nThe <strong>continuity<\/strong> <strong>of energy supply<\/strong> depends on the reliability of EPS elements, protection system operation and it depends on reserves in generating and transmitting devices.\r\n<h1>Wide area synchronous grids<\/h1>\r\n<div class=\"textbox shaded\"><strong>Wide area synchronous grids<\/strong> (also known as synchronous zones) are\u00a0 electrical grids operating\u00a0 at a regional scale that operates at a synchro-nized frequency and are electrically tied together during normal system conditions.<\/div>\r\n&nbsp;\r\n<div><strong>The largest synchronous zone is the synchronous grid of Continental Europe (ENTSO-E).<\/strong><\/div>\r\n<div>The <strong>basic condition<\/strong>, which must be fulfilled by an electric power system of the country that wants to be joined to the connected system is keeping frequency at <em><strong>f = 50Hz<\/strong><\/em>. Detailed requirements are:<\/div>\r\n<ul>\r\n \t<li>standard deviation for 90% and 99% measuring intervals is lower than respectively 40 mHz and 60 mHz for the whole considered monthly period,<\/li>\r\n \t<li>number of days in a month with given frequency 49,99 or 50,01 does not exceed eight days.<\/li>\r\n<\/ul>\r\n<h1>European Network of Transmission Systems<\/h1>\r\nEuropean countries are connected with one another for decades now and transmission system operators have been working in regions since the 1950s.\r\nTSOs are responsible for security of supply in their area. In order to do this they plan decades ahead how the grid will need to evolve depending on the big trends in the power system.\r\nFrom a year in advance to real time, TSOs run a continuous series of calculations and adapt their assumptions constantly to new issues arising on their grid but also that of their neighbours \u2013 notably through RSCs but also through the ENTSO-E awareness system.\r\n\r\n[caption id=\"attachment_106\" align=\"aligncenter\" width=\"427\"]<img class=\"wp-image-106 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c617f9e07d7c.png\" alt=\"\" width=\"427\" height=\"459\" \/> Fig. 1.8 Evolution of TSOs' organizations.[\/caption]\r\n\r\n<div><strong>The ENTSO-E System Operations activities:<\/strong><\/div>\r\n<ul>\r\n \t<li>Developing European operational standards,<\/li>\r\n \t<li>Protecting critical infrastructure systems,<\/li>\r\n \t<li>Developing and maintaining a common system operation channel: the Electronic Highway,<\/li>\r\n \t<li>Developing a common model of the grid that can be used for system operation,<\/li>\r\n \t<li>Defining a methodology for dealing with operational reserves \u2013 power reserves that can be activated to maintain the grid balanced,<\/li>\r\n \t<li>Classification &amp; follow up of operational incidents,<\/li>\r\n \t<li>Promotion and enhancement of coordinated system operation and services notably through the regional service providers.<\/li>\r\n<\/ul>\r\n<div>The System Operations Committee has 5 permanent regional groups based on the synchronous areas RG Continental Europe, RG Nordic, RG Baltic, RG Great Britain, and Ireland-Northern Ireland. RGs ensure compatibility between system operations on the one side and market solutions and system development issues on the other.<\/div>\r\n<div><\/div>\r\n<div>\r\n\r\n[caption id=\"attachment_109\" align=\"aligncenter\" width=\"426\"]<img class=\"wp-image-109 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61805ee3868.png\" alt=\"\" width=\"426\" height=\"456\" \/> Fig. 1.9 ENTSO-E regional groups.[\/caption]\r\n\r\n&nbsp;\r\n\r\n<\/div>\r\n<div><\/div>\r\n<h1>Energy net generation per country<\/h1>\r\n<div>\r\n\r\n[caption id=\"attachment_111\" align=\"aligncenter\" width=\"925\"]<img class=\"wp-image-111 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618b6182182.png\" alt=\"\" width=\"925\" height=\"526\" \/> Fig. 1.10 Energy net generation per country[\/caption]\r\n<h1 id=\"UlhIYZk\">Coal electricity generation per country<\/h1>\r\n<\/div>\r\n\r\n[caption id=\"attachment_120\" align=\"aligncenter\" width=\"592\"]<img class=\"wp-image-120 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618d9cbf63a.png\" alt=\"\" width=\"592\" height=\"326\" \/> Fig. 1.11 Hard coal and lignite as percentage of national electricity production.[\/caption]\r\n\r\n<strong>Western Europe is phasing out coal<\/strong>, but Eastern Europe is sticking to it. Three more Member States announced coal phase-outs in 2017 - Netherlands, Italy and Portugal. They join France and the UK in committing to phase-out coal, while Eastern European countries are sticking to coal. The debate in Germany, Europe\u2019s largest coal and lignite consumer, is ongoing and will only be decided in 2019.\r\n\r\n[caption id=\"attachment_119\" align=\"aligncenter\" width=\"426\"]<img class=\"wp-image-119 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618d611a4ba.png\" alt=\"\" width=\"426\" height=\"339\" \/> Fig. 1.12 Coal phase-out years and operational capacity[\/caption]\r\n\r\n[caption id=\"attachment_121\" align=\"aligncenter\" width=\"593\"]<img class=\"wp-image-121 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618df1adf69.png\" alt=\"\" width=\"593\" height=\"323\" \/> Fig. 1.13 Lignite electricity generation (top 5 countries). Source: The European Power Sector in 2017, Agora Energiewende[\/caption]\r\n\r\nNew renewables generation sharply increased <strong>in 2017, with wind, solar and biomass overtaking coal for the first time<\/strong>. Since Europe\u2018s hydro potential is largely tapped, the increase in renewables comes from wind, solar and biomass generation. They rose by 12% in 2017 to 679 Terawatt hours, putting wind, solar and biomass above coal generation for the first time. This is incredible progress, considering just five years ago, coal generation was more than twice that of wind, solar and biomass.\r\n\r\n[caption id=\"attachment_123\" align=\"aligncenter\" width=\"592\"]<img class=\"wp-image-123 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618e8480419.png\" alt=\"\" width=\"592\" height=\"318\" \/> Fig. 1.14 Renewables versus coal electricity generation. Source: The European Power Sector in 2017, Agora Energiewende[\/caption]\r\n\r\nIn 2017, renewables generated 30% of Europe's electricity for the first time. Wind, solar and biomass grew to 20,9% of the EU electricity mix. This is up from just 9,7% in 2010, and represents an average growth of 1,7 percentage points per year. Wind had 46% of the EU renewables growth from 2011 to 2014, but this increased to 72% of the growth from 2014 to 2017. In the last 7 years, wind+solar+biomass increased its share of electricity production in every country, but at very different rates.\r\n\r\n[caption id=\"attachment_125\" align=\"aligncenter\" width=\"290\"]<img class=\"wp-image-125 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618f076d4bb.png\" alt=\"\" width=\"290\" height=\"295\" \/> Fig. 1.15 Changes in non-hydro renewables generation by type. Source: The European Power Sector in 2017, Agora Energiewende[\/caption]\r\n\r\n[caption id=\"attachment_126\" align=\"aligncenter\" width=\"592\"]<img class=\"wp-image-126 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618f4d6bea3.png\" alt=\"\" width=\"592\" height=\"295\" \/> Fig. 1.16 Wind, solar and biomass as percentage of national electricity production. Source: The European Power Sector in 2017, Agora Energiewende[\/caption]\r\n<h1>France - Energy System Overview<\/h1>\r\n<div>France has over 63,1 GW (48,3% of total capacity) of generating power installed in nuclear power stations. France produces in them 71,6% of energy generated in the country. It is the highest share of nuclear power stations in the total production of electricity in the world. <span style=\"text-align: left;color: #333333;text-indent: 0px;letter-spacing: normal;font-family: 'Montserrat',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;text-decoration: none;float: none;cursor: text;background-color: #ffffff\">Electricity Generation<\/span>: 549,6 TWh 18% renewables (IEA average: 24%).<\/div>\r\n<div>French transmission system:<\/div>\r\n<ul>\r\n \t<li>Circuit Length \u2013 105,000 km,<\/li>\r\n \t<li>Voltage Level 400-380 kV \u2013 21%,<\/li>\r\n \t<li>Voltage Level 220-150 kV \u2013 26%,<\/li>\r\n \t<li>Voltage Level 132-50 kV \u2013 53%,<\/li>\r\n<\/ul>\r\nConnected with the systems of Belgium, Luxembourg, Switzerland, Italy, Denmark and Spain.\r\n\r\n[caption id=\"attachment_130\" align=\"aligncenter\" width=\"450\"]<img class=\"wp-image-130 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61938d65fa5.png\" alt=\"\" width=\"450\" height=\"449\" \/> Fig. 1.17 Electricity generation in France: 549,6 TWh 18% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com[\/caption]\r\n<h1>Germany - Energy System Overview<\/h1>\r\n<div>Energy generation in Germany is based on coal (43%), renevables (31%) nuclear Energy (13%) and gas (13%). <span style=\"text-align: left;color: #333333;text-indent: 0px;letter-spacing: normal;font-family: 'Montserrat',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;text-decoration: none;float: none;cursor: text;background-color: #ffffff\">Electricity Generation<\/span>: 642,9 TWh 31% renewables (IEA average: 24%).\r\nThere are four transmission system operators (TSOs) in Germany. On 10 November 2017, there were 879 distribution system operators registered with the Federal Network Agency in Germany. Close to 800 of these DSOs operate networks with less than 100,000 connected costumers.<\/div>\r\n<div>German transmission system:<\/div>\r\n<ul>\r\n \t<li>Circuit Length \u2013 35,000 km,<\/li>\r\n \t<li>Voltage Level 400-380 kV \u2013 59%,<\/li>\r\n \t<li>Voltage Level 220-150 kV \u2013 41%,<\/li>\r\n<\/ul>\r\n<div>Strong connections of its system with neighbouring systems (AC 220kV, 380kV and under-sea HVDC lines).<\/div>\r\n\r\n[caption id=\"attachment_132\" align=\"aligncenter\" width=\"450\"]<img class=\"wp-image-132 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61946b0c76d.png\" alt=\"\" width=\"450\" height=\"449\" \/> Fig. 1.18 Electricity generation in Germany 642,9 TWh 31% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com[\/caption]\r\n\r\n&nbsp;\r\n<h1>Italy - Energy System Overview<\/h1>\r\n<p id=\"GTchtJC\">In Italy electric energy generation is based on thermal power plants (15% on coal, 42% on gas and 4% on heavy oil) and many types of renewables. <span style=\"text-align: left;color: #333333;text-indent: 0px;letter-spacing: normal;font-family: 'Montserrat',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;text-decoration: none;float: none;cursor: text;background-color: #ffffff\">Electricity Generation<\/span>: 284,1 TWh 39% renewables (IEA average: 24%).\r\nThe only nuclear power plant in Italy was closed in 1987. As of 2018, Italy is one of only two countries, along with Lithuania, that completely phased out nuclear power for electricity generation after having operational reactors.\r\nItalian transmission system:\r\nCircuit Length \u2013 72,600 km,\r\nVoltage Level 400-380 kV \u2013 19%,\r\nVoltage Level 220-150 kV \u2013 81%,\r\nConnected with neighbouring systems by AC 220kV, 380kV and under-sea HVDC lines.<\/p>\r\n\r\n\r\n[caption id=\"attachment_134\" align=\"aligncenter\" width=\"450\"]<img class=\"wp-image-134 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c619546f37a9.png\" alt=\"\" width=\"450\" height=\"449\" \/> Fig. 1.19. Electricity generation in Italy: 284,1 TWh 39% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com[\/caption]\r\n<h1>Poland - Energy System Overview<\/h1>\r\nCurrently (as at 31 December 2017) there are generating facilities with a net capacity totalling around 43,612 gigawatts (GW). Electricity Generation: 166,2 TWh 14% renewables (IEA average: 24%).\r\nHowever, this capacity is not the same as the output available on the electricity market to meet demand at any given time, as the latter depends on the weather conditions. The supply is safeguarded almost entirely by conventional power plants.\r\nIn 2017, conventional forms of energy generated 89,89 percent of electricity in Poland.\r\n\r\n[caption id=\"attachment_137\" align=\"aligncenter\" width=\"450\"]<img class=\"wp-image-137 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c619616a912b.png\" alt=\"\" width=\"450\" height=\"449\" \/> Fig. 1.20 Electricity generation in Poland: 166,2 TWh 14% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com[\/caption]\r\n\r\nAs of 2016, there were 172 DSOs operating in Poland, and among them, five large DSOs belonging to vertically integrated undertakings. As these five DSOs are parts of vertically integrated undertakings they are subject to an obligation to separate distribution activities from generation operations or other economic activities of a vertically integrated undertaking (as a result of unbundling requirements).\r\n<p style=\"text-align: center\">Tab. 1.1 Market share of Polish electricity companies. Source: Agora Energiewende, PTPiREE 2016\r\n<img class=\"alignnone size-full wp-image-139 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61966eae90e.png\" alt=\"\" \/><\/p>\r\nPolish distribution networks are typical for Europe and they have got total length:\r\n<ul>\r\n \t<li>110kV\u00a0lines \u2013\u00a033 300 km<\/li>\r\n \t<li>MV lines \u2013 296 920 km (6kV, 10kV, 15kV, 20kV, 30kV)<\/li>\r\n \t<li>LV lines \u2013 426 416 km<\/li>\r\n<\/ul>\r\nPolish TSO \u2013 PSE performs the duties of the transmission system operator using its own transmission grid of the highest voltage, which consists of (2018):\r\n<ul>\r\n \t<li>258 lines with a total length of 14\u00a0195 km, including:\r\n- 1 line of 750kV voltage with a length of 114 km,\r\n- 93\u00a0lines of 400kV voltage \u2013 6\u00a0326 km,\r\n- 164 lines of 220kV voltage \u2013 7\u00a0755\u00a0km,<\/li>\r\n \t<li>106 extra-high voltage (EHV) substations<\/li>\r\n \t<li>under-sea 450kV DC connection between Poland and Sweden, with a total length of 254 km (127 km belongs to PSE).<\/li>\r\n<\/ul>\r\n[caption id=\"attachment_141\" align=\"aligncenter\" width=\"546\"]<img class=\"wp-image-141 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c619765205d5.png\" alt=\"\" width=\"546\" height=\"513\" \/> Fig. 1.21. Transmission network development plan in Poland until 2025[\/caption]\r\n\r\n&nbsp;\r\n\r\n[caption id=\"attachment_727\" align=\"aligncenter\" width=\"1048\"]<img class=\"wp-image-727\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/PSE-plan-sieci.jpg\" alt=\"\" width=\"1048\" height=\"948\" \/> Fig. 1.22. Transmission network and its development plan in Poland until 2027[\/caption]\r\n\r\n&nbsp;\r\n<h1><span style=\"color: #3366ff\">Energy mix of electricity generation and overall mix<\/span><\/h1>\r\n<span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">So far, we have discussed the energy mixes of electricity generation, for example Europe:<\/span><\/span><\/span>\r\n\r\n<strong><span style=\"color: #ff00ff\">4158 TWh\/year or 14969 PJ\/year<\/span><\/strong>\r\n\r\n[caption id=\"attachment_141\" align=\"aligncenter\" width=\"716\"]<img class=\"wp-image-141 \" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz.png\" alt=\"\" width=\"716\" height=\"358\" \/> Fig. 1.22. Electricity generation by source[\/caption]\r\n\r\n<span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">How does this mix differ from the overall energy mix?<\/span><\/span><\/span>\r\n\r\n<strong><span style=\"color: #ff00ff\">58909<\/span><span style=\"color: #ff00ff\"><strong> PJ\/y<\/strong>ear<\/span><\/strong>\r\n\r\n[caption id=\"attachment_141\" align=\"aligncenter\" width=\"716\"]<img class=\"wp-image-141 \" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-1.png\" alt=\"\" width=\"716\" height=\"358\" \/> Fig. 1.23. Total final energy consuption[\/caption]\r\n\r\n&nbsp;\r\n\r\n<span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">And from total energy supply?<\/span><\/span><\/span>\r\n\r\n<strong><span style=\"color: #ff00ff\">81141<\/span><span style=\"color: #ff00ff\"><strong> PJ\/y<\/strong>ear<\/span><\/strong>\r\n\r\n[caption id=\"attachment_141\" align=\"aligncenter\" width=\"738\"]<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-4.png\" width=\"738\" height=\"368\" alt=\"\" class=\"wp-image-1124 alignnone \" \/> Fig. 1.23. Total energy supply[\/caption]\r\n\r\n&nbsp;\r\n\r\n<span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">And who consumes this energy?<\/span><\/span><\/span>\r\n\r\n<strong><span style=\"color: #ff00ff\">\u00a0<\/span><\/strong>\r\n\r\n[caption id=\"attachment_141\" align=\"aligncenter\" width=\"728\"]<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-5.png\" width=\"728\" height=\"364\" alt=\"\" class=\"wp-image-1126 alignnone \" \/> Fig. 1.24. Total final energy consumption[\/caption]\r\n\r\n&nbsp;\r\n<h1><span style=\"color: #ff6600\">Some additional charts to study for yourself - how the energy mixes are changing\r\n<\/span><\/h1>\r\n<h1><span style=\"color: #ff6600\">POLAND<\/span><\/h1>\r\n<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10.png\" width=\"710\" height=\"395\" alt=\"\" class=\"wp-image-1132 aligncenter\" \/><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8.png\" width=\"729\" height=\"403\" alt=\"\" class=\"wp-image-1130 aligncenter\" \/>\r\n\r\n<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6.png\" width=\"723\" height=\"400\" alt=\"\" class=\"wp-image-1128 aligncenter\" \/>\r\n<h1><span style=\"color: #ff6600\">GERMANY<\/span><\/h1>\r\n<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11.png\" width=\"793\" height=\"438\" alt=\"\" class=\"wp-image-1133 aligncenter\" \/>\r\n\r\n&nbsp;\r\n\r\n<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13.png\" width=\"779\" height=\"431\" alt=\"\" class=\"wp-image-1135 aligncenter\" \/>\r\n<h1><span style=\"color: #ff6600\">FRANCE<\/span><\/h1>\r\n<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14.png\" width=\"770\" height=\"426\" alt=\"\" class=\"wp-image-1136 aligncenter\" \/>\r\n\r\n<img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15.png\" width=\"798\" height=\"442\" alt=\"\" class=\"wp-image-1137 aligncenter\" \/>\r\n\r\n<h1>Questions<\/h1>\r\n1. What is the power system?(present different approaches)\r\n2. What are the basic elements of power system? (give description)\r\n3. What is the difference between electric power system and other economy systems?\r\n4. What are typical voltage levels for transmission and\u00a0distribution?\r\n5. What are the levels of electric power system? (give description)\r\n6. What are the most important parameters of electric power system operation?\r\n7. What is ENTSOE?\r\n8. Describe difference between: installed power of system, maximum capacity and available capacity.\r\n9. Which voltage level network has the largest total length?\r\n\r\n&nbsp;\r\n\r\n&nbsp;","rendered":"<h1>Definition of EPS<\/h1>\n<p style=\"text-align: justify\">A <strong>system<\/strong> is a set of devices interconnected to fulfill previously specified function.<\/p>\n<p style=\"text-align: justify\">An <strong>energy system<\/strong> is defined as all components related to the production, conversion, delivery, and use of energy. The system structure, so a system itself is formally determined by a\u00a0 pair of ordered sets <em>S = &lt;U, K&gt;<\/em>, where <em>U<\/em> \u2013 a set of devices and <em>K<\/em> \u2013 a set of relations of interconnections of these devices, it is a set of configurations.<\/p>\n<p>Energy systems are divided according to energy carriers on:<\/p>\n<ul>\n<li>electric power systems,<\/li>\n<li>thermal systems,<\/li>\n<li>gas-energy systems,<\/li>\n<li>systems of solid fuel supply<\/li>\n<li>systems of liquid fuel supply.<\/li>\n<\/ul>\n<p>An\u00a0<strong>electric power system\u00a0<\/strong>is a network of electrical components deployed to supply, transfer, and use electric power.<\/p>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Basic elements of electric power system (<strong>EPS<\/strong>) are:<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>generating units (power plants),<\/li>\n<li>transmission network,<\/li>\n<li>distribution network.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h1>Main components of EPS<\/h1>\n<p style=\"text-align: justify\">A <strong>generating unit<\/strong> is created by a separated set of power plants\u2019 devices, which form independent technologic series of electric energy generation and which can generate electric energy by itself. Generating units are divided into traditional: coal, nuclear, gas, liquid fuels, and, recently quickly developing units based on renewable energy sources: hydro, wind, biomass and others.<\/p>\n<p><img width=\"158\" height=\"121\" class=\"size-full wp-image-61 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/img_5c138aaa438af.png\" alt=\"\" \/><\/p>\n<p style=\"text-align: justify\">An <strong>electric power network<\/strong> is a set of cooperating electric power lines and substations used for transmission, transformation and distribution of electric energy on specified area. Lines are divided into overhead with bare and insulated conductors and into cables. The following elements are met in substations: transformers, reactors (choking coils), capacitors, bus bars, switches and others.<\/p>\n<p>&nbsp;<\/p>\n<div style=\"text-align: justify\"><strong>Transmission networks<\/strong> belong to transmission electric power system which encompasses lines and substations of the highest voltages. They serve for the transmission of electrical energy over long distances. In Poland these are lines of voltages over 110 kV (220 kV and 400 kV). Voltage 400 kV is treated as evolutional.<\/div>\n<div><img width=\"120\" height=\"156\" class=\"size-full wp-image-62 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/img_5c138ab6e50da.png\" alt=\"\" \/><\/div>\n<div style=\"text-align: justify\"><strong>Distribution networks<\/strong> belong to distribution power systems which contain networks and power substations of low voltages, medium voltages and high voltages. They are used for distribution of electric energy between customers. In Poland these are low voltage networks (0.4 kV, 0.66 kV), medium voltage networks (6 kV, 10 kV, 15 kV, 20 kV, 30 kV) and high voltage networks \u2013 110 kV.<\/div>\n<p><img width=\"205\" height=\"100\" class=\"size-full wp-image-63 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/img_5c138ace5b32c.png\" alt=\"\" \/><\/p>\n<p>&nbsp;<\/p>\n<h1>Characteristic features of EPS<\/h1>\n<p style=\"text-align: justify\">The <strong>characteristic feature of EPS<\/strong> is that it <strong>covers large territory<\/strong> because usually it is the whole country.<br \/>\nLong distances in case of large countries like Russia, Canada, USA, Australia, Brazil force to intensive research investigations in the area of electrical energy transmission technology on long distances (especially high voltage direct current transmission lines &#8211; HVDC).<\/p>\n<p>With current initiatives on smart grid and sustainable energy, <strong>distributed generations (DGs)<\/strong> and <strong>renewable energy sources (RES)<\/strong>, characterized by relatively small powers are going to play vital role in the emerging <strong>small<\/strong>, <strong>independent<\/strong>, <strong>local electrical power systems<\/strong>.<\/p>\n<p id=\"RvYuehK\">From cybernetics point of view EPS is a huge system constituting multi-input and multi-output arrangement, relatively separated, dissipative, weakly self-adjustable and additionally controlled by the staff.<\/p>\n<figure id=\"attachment_77\" aria-describedby=\"caption-attachment-77\" style=\"width: 648px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-77 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c6157f66038a.png\" alt=\"\" width=\"648\" height=\"385\" \/><figcaption id=\"caption-attachment-77\" class=\"wp-caption-text\">Fig. 1.1 Cybernetical approach to EPS<\/figcaption><\/figure>\n<p>The extension\/development of EPS is directly connected with other branches of economy for which EPS serves and on which its development and existence depends. These are industry of fuel mining and reprocessing, other electric power systems, hydro economy of the country, machine-building industry and scientific background, infrastructure of the country, environment, etc.<\/p>\n<p>&nbsp;<\/p>\n<div class=\"textbox shaded\">\n<p>The system is characterized by many parameters. The most important of them are the following:<\/p>\n<ul>\n<li>peak power demanded by customers,<\/li>\n<li>annual production of electric energy,<\/li>\n<li>power installed in generating units,<\/li>\n<li>power of the largest generating unit,<\/li>\n<li>the highest nominal voltage of the transmission network,<\/li>\n<li>the longest distances of power flow,<\/li>\n<li>power structure,<\/li>\n<li>network structure.<\/li>\n<\/ul>\n<\/div>\n<p><strong>Definitions of important parameters:<\/strong><\/p>\n<p><strong>Installed power <\/strong>of domestic power plants, it is the sum of nominal powers of all generating units (eg Poland at the end of 2002 was 34715MW).<br \/>\n<strong>Maximum output capacity<\/strong> of commercial power plants in the system, it is the sum of the continuous powers of all generating units in the system, produced by thermal generators in the continuous way in the time of at least 15 hours, and by water generators in the time of at least 5 hours, at nominal conditions of work acknowledged by tests. (eg Poland it was 31887 MW in 2004)<\/p>\n<p><strong>Available capacity<\/strong> of the domestic power plants it is maximum output capacity reduced by planned outages (maintenance), periodical losses, exploitation losses and others (eg in Poland in 2004 it was 26865 MW).<\/p>\n<p><strong>Maximum annual demand for power<\/strong> it is power measured on the lines leading the current out from power stations (eg in Poland in 2004 it was on December 23 at 17.00 and it was 23108 MW) .<\/p>\n<p>&nbsp;<\/p>\n<p>Electric power system, <strong>as distinct from other economy systems<\/strong>, realizes tasks connected with the production, transmission and distribution of the product with immediate supply on any request of the client. It is characterized by the<strong> lack of possibility to store the product<\/strong>. All the production is consumed immediately. Thus the customers have the influence on production scale. It definitely determines current control of EPS operation.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<h1>Energy storage<\/h1>\n<p>Electric energy cannot be directly stored, but some other energy carriers may be used to do it. The only one, commonly used way of electrical energy storage, is a pumped power station, in which during hours of small load the water is pumped from the lower reservoir to the upper one.<\/p>\n<figure id=\"attachment_76\" aria-describedby=\"caption-attachment-76\" style=\"width: 402px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-76 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c6156e27830f.png\" alt=\"\" width=\"402\" height=\"222\" \/><figcaption id=\"caption-attachment-76\" class=\"wp-caption-text\">Fig. 1.2 General idea of pumped hydro power station. Source: www.energy-storage.news, EnergyAustralia<\/figcaption><\/figure>\n<p>Last decade is a period of intense development of various types of energy storage other than pumped-storage hydroelectricity. Leading technologies are:<br \/>\n<span style=\"text-decoration: underline\">Thermal power stations:<\/span><\/p>\n<ul>\n<li>Molten salt<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline\">Electrochemical:<\/span><\/p>\n<ul>\n<li>Lithium batteries,<\/li>\n<li>Sodium-sulfur batteries (NaS),<\/li>\n<li>Lead-acid batteries,<\/li>\n<li>Nickel batteries.<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline\">Electromechanical:<\/span><\/p>\n<ul>\n<li>Flywheels,<\/li>\n<li>Compressed-Air Energy Storage,<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline\">Chemical:<\/span><\/p>\n<ul>\n<li>Hydrogen storage.<\/li>\n<\/ul>\n<figure id=\"attachment_79\" aria-describedby=\"caption-attachment-79\" style=\"width: 810px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-79 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c615ab4e97a2.png\" alt=\"\" width=\"810\" height=\"400\" \/><figcaption id=\"caption-attachment-79\" class=\"wp-caption-text\">Fig. 1.3 Technology maturity of storage. Source: Christiansen, C. and Murray, B. 2015. AECOM Energy Storage Study.<\/figcaption><\/figure>\n<h1>Load profile<\/h1>\n<p><strong>Power structure<\/strong> is characterized by the way of covering system loads so it contains data about generating units. The curve of total system load by the powers demanded during 24 hours P(t) has the influence on the power structure.<\/p>\n<div class=\"wp-nocaption wp-image-731 aligncenter\"><img class=\"wp-image-731 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/06\/img_5cfe47414151d.png\" alt=\"\" width=\"635\" height=\"435\" \/><\/div>\n<p>&nbsp;<\/p>\n<p><strong>Basic load<\/strong> is covered by steam power plants characterized by small per-unit fuel costs, nuclear power plants and thermal-electric power stations. <strong>Midload<\/strong> power is covered by older thermal power stations and renewable sources.<br \/>\nCovering of <strong>peak load<\/strong> should be guaranteed by hydro generating units, gas units and liquid fuel units.<\/p>\n<figure id=\"attachment_82\" aria-describedby=\"caption-attachment-82\" style=\"width: 440px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-82 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c615f2a8017f.png\" alt=\"\" width=\"440\" height=\"307\" \/><figcaption id=\"caption-attachment-82\" class=\"wp-caption-text\">Fig. 1.4 Generation power structure and demand. Source: www.pse.pl<\/figcaption><\/figure>\n<h1>System structure<\/h1>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">EPS can be divided on three hierarchical levels:<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>generation level,<\/li>\n<li>transmission level,<\/li>\n<li>distribution level.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<figure id=\"attachment_83\" aria-describedby=\"caption-attachment-83\" style=\"width: 543px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-83\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61601c1846a.png\" alt=\"\" width=\"543\" height=\"722\" \/><figcaption id=\"caption-attachment-83\" class=\"wp-caption-text\">Fig. 1.5 EPS levels and elements.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The <strong>level of generation<\/strong> is created by big system power stations which <strong>generators<\/strong> are connected to <strong>HV transmission network<\/strong> (400 kV, 220 kV) and to HV distribution network (110kV), through step-up transformers (the voltage on generators\u2019 terminals is about 20 kV &#8211; to small to send the power on long distances).<\/p>\n<p>The <strong>level of transmission<\/strong> is created by <strong>lines and electric power substations 750 kV, 400 kV and 220 kV<\/strong>.<br \/>\nThe different levels of voltages are coupled by\u00a0 transformers (the voltage ratio &gt; 2) or by auto-transformers (ratio \u2264 2). Reactive power compensation of opposite sign is used in HV transmission network because of its high reactive power generation.\u00a0In EHV\/110kV sub-stations capacitor banks for reactive power compensation are used on 110 kV side.<\/p>\n<p>The <strong>level of distribution<\/strong> is created by <strong>networks and substations of medium and low voltages<\/strong>.<br \/>\nCapacitor banks for reactive power compensation are used in:<\/p>\n<ul>\n<li>substations 110kV\/MV on the medium voltage side,<\/li>\n<li>MV and LV networks.<\/li>\n<\/ul>\n<p>Industrial customers are supplied directly from MV network and household customers are supplied from LV network.<\/p>\n<p>&nbsp;<\/p>\n<p>Electric power systems of different countries are often connected together and such systems are called integrated systems. These systems are organizationally independent but, in reality, they create one electric power grid.\u00a043 TSOs from 36 countries are members of ENTSO-E (the European Network of Transmission System Operators for Electricity).<\/p>\n<figure id=\"attachment_89\" aria-describedby=\"caption-attachment-89\" style=\"width: 448px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-89 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c6161ce4c291.png\" alt=\"\" width=\"448\" height=\"343\" \/><figcaption id=\"caption-attachment-89\" class=\"wp-caption-text\">Fig. 1.6 ENTSOE countries . Source: www.entsoe.eu<\/figcaption><\/figure>\n<h1>Environmental pollution<\/h1>\n<p>The <strong>generation, transmission<\/strong> and <strong>distribution<\/strong> of electric energy cause more and more <strong>environmental pollution<\/strong>.<\/p>\n<div class=\"textbox shaded\">\n<p>Main but not only one cause of pollution is burning of organic fuels, which is accompanied by:<\/p>\n<ul>\n<li>emission of : SO2, NOx, dust, CO2, CO and heat to the atmosphere,<\/li>\n<li>thermal pollution (heating) and chemical pollution of waters,<\/li>\n<li>devastation of the area by ash dumps.<\/li>\n<\/ul>\n<\/div>\n<p>&nbsp;<\/p>\n<p>Additionally the following things are connected with electrical power engineering:<\/p>\n<ul>\n<li>noise pollution,<\/li>\n<li>electrical power engineering disturbances,<\/li>\n<li>stray currents in the earth,<\/li>\n<li>enlarged corrosion,<\/li>\n<li>climatic changes,<\/li>\n<li>wood cutting for electrical lines, fuel transport and others.<\/li>\n<\/ul>\n<div>Nuclear power plants may cause danger of radioactive pollution of atmosphere and waters. <strong>All\u00a0 parts of the nuclear fuel\u00a0 cycle produce some radioactive waste<\/strong> and the relatively modest cost of managing and disposing of this is part of the electricity cost.<\/div>\n<div>European Union and universal standards (Kyoto protocol) request sharp requirements on environmental protection. It is tied with meaningful financial involvement which has to be used for this goal.<\/div>\n<p>The main objective in managing and disposing of radioactive (or other) waste is to protect people\u00a0 and\u00a0 the\u00a0 environment.\u00a0 This\u00a0 means\u00a0 isolating\u00a0 or\u00a0 diluting\u00a0 the\u00a0 waste\u00a0 so\u00a0 that\u00a0 the\u00a0 rate\u00a0 or concentration\u00a0 of\u00a0 any\u00a0 radionuclides\u00a0 returned\u00a0 to\u00a0 the\u00a0 biosphere\u00a0 is\u00a0 harmless.\u00a0 To\u00a0 achieve\u00a0 this, <strong>practically all radioactive wastes are contained and managed<\/strong>\u00a0 \u2013 some clearly need deep and permanent burial. Many long-term waste management options have been\u00a0 investigated\u00a0 worldwide\u00a0 which\u00a0 seek\u00a0 to\u00a0 provide\u00a0 publicly\u00a0 acceptable,\u00a0 safe\u00a0 and environmentally sound solutions to the management of radioactive waste.<\/p>\n<h1>Basic parameters<\/h1>\n<p>The work effectiveness of electricity receivers, fed from the system, depends on parameters of energy supplied from the system.<\/p>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Basic parameters of electrical energy are following:<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>frequency,<\/li>\n<li>voltage phase symmetry,<\/li>\n<li>the content of non-linear distortions in voltage curve,<\/li>\n<li>continuity of energy supply.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_97\" aria-describedby=\"caption-attachment-97\" style=\"width: 373px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-97 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c616f8d02a4c.png\" alt=\"\" width=\"373\" height=\"278\" \/><figcaption id=\"caption-attachment-97\" class=\"wp-caption-text\">Fig. 1.7 Three phase voltage.<\/figcaption><\/figure>\n<p>The <strong>most important parameter<\/strong>, determining the operation of EPS \u2013 <strong>frequency<\/strong> \u2013 depends on the active power margin in generating units and it depends on the operation of frequency automatic control systems in EPS.<\/p>\n<p>Proper <strong>voltage levels<\/strong> are results of reactive power reserves in sources of this power and they depend on the operation of voltage automatic regulation in EPS.<\/p>\n<p>The <strong>phase symmetry<\/strong> depends on EPS elements\u2019 symmetry and on distribution on individual phases of single-phase receivers.<\/p>\n<p>The <strong>shape of voltage curve<\/strong>, not being sinusoidal, results from actual continuous rise of the share of non-linear receivers in EPS. These receivers generate higher current harmonics.<\/p>\n<p>The <strong>continuity<\/strong> <strong>of energy supply<\/strong> depends on the reliability of EPS elements, protection system operation and it depends on reserves in generating and transmitting devices.<\/p>\n<h1>Wide area synchronous grids<\/h1>\n<div class=\"textbox shaded\"><strong>Wide area synchronous grids<\/strong> (also known as synchronous zones) are\u00a0 electrical grids operating\u00a0 at a regional scale that operates at a synchro-nized frequency and are electrically tied together during normal system conditions.<\/div>\n<p>&nbsp;<\/p>\n<div><strong>The largest synchronous zone is the synchronous grid of Continental Europe (ENTSO-E).<\/strong><\/div>\n<div>The <strong>basic condition<\/strong>, which must be fulfilled by an electric power system of the country that wants to be joined to the connected system is keeping frequency at <em><strong>f = 50Hz<\/strong><\/em>. Detailed requirements are:<\/div>\n<ul>\n<li>standard deviation for 90% and 99% measuring intervals is lower than respectively 40 mHz and 60 mHz for the whole considered monthly period,<\/li>\n<li>number of days in a month with given frequency 49,99 or 50,01 does not exceed eight days.<\/li>\n<\/ul>\n<h1>European Network of Transmission Systems<\/h1>\n<p>European countries are connected with one another for decades now and transmission system operators have been working in regions since the 1950s.<br \/>\nTSOs are responsible for security of supply in their area. In order to do this they plan decades ahead how the grid will need to evolve depending on the big trends in the power system.<br \/>\nFrom a year in advance to real time, TSOs run a continuous series of calculations and adapt their assumptions constantly to new issues arising on their grid but also that of their neighbours \u2013 notably through RSCs but also through the ENTSO-E awareness system.<\/p>\n<figure id=\"attachment_106\" aria-describedby=\"caption-attachment-106\" style=\"width: 427px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-106 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c617f9e07d7c.png\" alt=\"\" width=\"427\" height=\"459\" \/><figcaption id=\"caption-attachment-106\" class=\"wp-caption-text\">Fig. 1.8 Evolution of TSOs&#8217; organizations.<\/figcaption><\/figure>\n<div><strong>The ENTSO-E System Operations activities:<\/strong><\/div>\n<ul>\n<li>Developing European operational standards,<\/li>\n<li>Protecting critical infrastructure systems,<\/li>\n<li>Developing and maintaining a common system operation channel: the Electronic Highway,<\/li>\n<li>Developing a common model of the grid that can be used for system operation,<\/li>\n<li>Defining a methodology for dealing with operational reserves \u2013 power reserves that can be activated to maintain the grid balanced,<\/li>\n<li>Classification &amp; follow up of operational incidents,<\/li>\n<li>Promotion and enhancement of coordinated system operation and services notably through the regional service providers.<\/li>\n<\/ul>\n<div>The System Operations Committee has 5 permanent regional groups based on the synchronous areas RG Continental Europe, RG Nordic, RG Baltic, RG Great Britain, and Ireland-Northern Ireland. RGs ensure compatibility between system operations on the one side and market solutions and system development issues on the other.<\/div>\n<div><\/div>\n<div>\n<figure id=\"attachment_109\" aria-describedby=\"caption-attachment-109\" style=\"width: 426px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-109 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61805ee3868.png\" alt=\"\" width=\"426\" height=\"456\" \/><figcaption id=\"caption-attachment-109\" class=\"wp-caption-text\">Fig. 1.9 ENTSO-E regional groups.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<\/div>\n<div><\/div>\n<h1>Energy net generation per country<\/h1>\n<div>\n<figure id=\"attachment_111\" aria-describedby=\"caption-attachment-111\" style=\"width: 925px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-111 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618b6182182.png\" alt=\"\" width=\"925\" height=\"526\" \/><figcaption id=\"caption-attachment-111\" class=\"wp-caption-text\">Fig. 1.10 Energy net generation per country<\/figcaption><\/figure>\n<h1 id=\"UlhIYZk\">Coal electricity generation per country<\/h1>\n<\/div>\n<figure id=\"attachment_120\" aria-describedby=\"caption-attachment-120\" style=\"width: 592px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-120 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618d9cbf63a.png\" alt=\"\" width=\"592\" height=\"326\" \/><figcaption id=\"caption-attachment-120\" class=\"wp-caption-text\">Fig. 1.11 Hard coal and lignite as percentage of national electricity production.<\/figcaption><\/figure>\n<p><strong>Western Europe is phasing out coal<\/strong>, but Eastern Europe is sticking to it. Three more Member States announced coal phase-outs in 2017 &#8211; Netherlands, Italy and Portugal. They join France and the UK in committing to phase-out coal, while Eastern European countries are sticking to coal. The debate in Germany, Europe\u2019s largest coal and lignite consumer, is ongoing and will only be decided in 2019.<\/p>\n<figure id=\"attachment_119\" aria-describedby=\"caption-attachment-119\" style=\"width: 426px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-119 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618d611a4ba.png\" alt=\"\" width=\"426\" height=\"339\" \/><figcaption id=\"caption-attachment-119\" class=\"wp-caption-text\">Fig. 1.12 Coal phase-out years and operational capacity<\/figcaption><\/figure>\n<figure id=\"attachment_121\" aria-describedby=\"caption-attachment-121\" style=\"width: 593px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-121 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618df1adf69.png\" alt=\"\" width=\"593\" height=\"323\" \/><figcaption id=\"caption-attachment-121\" class=\"wp-caption-text\">Fig. 1.13 Lignite electricity generation (top 5 countries). Source: The European Power Sector in 2017, Agora Energiewende<\/figcaption><\/figure>\n<p>New renewables generation sharply increased <strong>in 2017, with wind, solar and biomass overtaking coal for the first time<\/strong>. Since Europe\u2018s hydro potential is largely tapped, the increase in renewables comes from wind, solar and biomass generation. They rose by 12% in 2017 to 679 Terawatt hours, putting wind, solar and biomass above coal generation for the first time. This is incredible progress, considering just five years ago, coal generation was more than twice that of wind, solar and biomass.<\/p>\n<figure id=\"attachment_123\" aria-describedby=\"caption-attachment-123\" style=\"width: 592px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-123 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618e8480419.png\" alt=\"\" width=\"592\" height=\"318\" \/><figcaption id=\"caption-attachment-123\" class=\"wp-caption-text\">Fig. 1.14 Renewables versus coal electricity generation. Source: The European Power Sector in 2017, Agora Energiewende<\/figcaption><\/figure>\n<p>In 2017, renewables generated 30% of Europe&#8217;s electricity for the first time. Wind, solar and biomass grew to 20,9% of the EU electricity mix. This is up from just 9,7% in 2010, and represents an average growth of 1,7 percentage points per year. Wind had 46% of the EU renewables growth from 2011 to 2014, but this increased to 72% of the growth from 2014 to 2017. In the last 7 years, wind+solar+biomass increased its share of electricity production in every country, but at very different rates.<\/p>\n<figure id=\"attachment_125\" aria-describedby=\"caption-attachment-125\" style=\"width: 290px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-125 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618f076d4bb.png\" alt=\"\" width=\"290\" height=\"295\" \/><figcaption id=\"caption-attachment-125\" class=\"wp-caption-text\">Fig. 1.15 Changes in non-hydro renewables generation by type. Source: The European Power Sector in 2017, Agora Energiewende<\/figcaption><\/figure>\n<figure id=\"attachment_126\" aria-describedby=\"caption-attachment-126\" style=\"width: 592px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-126 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c618f4d6bea3.png\" alt=\"\" width=\"592\" height=\"295\" \/><figcaption id=\"caption-attachment-126\" class=\"wp-caption-text\">Fig. 1.16 Wind, solar and biomass as percentage of national electricity production. Source: The European Power Sector in 2017, Agora Energiewende<\/figcaption><\/figure>\n<h1>France &#8211; Energy System Overview<\/h1>\n<div>France has over 63,1 GW (48,3% of total capacity) of generating power installed in nuclear power stations. France produces in them 71,6% of energy generated in the country. It is the highest share of nuclear power stations in the total production of electricity in the world. <span style=\"text-align: left;color: #333333;text-indent: 0px;letter-spacing: normal;font-family: 'Montserrat',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;text-decoration: none;float: none;cursor: text;background-color: #ffffff\">Electricity Generation<\/span>: 549,6 TWh 18% renewables (IEA average: 24%).<\/div>\n<div>French transmission system:<\/div>\n<ul>\n<li>Circuit Length \u2013 105,000 km,<\/li>\n<li>Voltage Level 400-380 kV \u2013 21%,<\/li>\n<li>Voltage Level 220-150 kV \u2013 26%,<\/li>\n<li>Voltage Level 132-50 kV \u2013 53%,<\/li>\n<\/ul>\n<p>Connected with the systems of Belgium, Luxembourg, Switzerland, Italy, Denmark and Spain.<\/p>\n<figure id=\"attachment_130\" aria-describedby=\"caption-attachment-130\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-130 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61938d65fa5.png\" alt=\"\" width=\"450\" height=\"449\" \/><figcaption id=\"caption-attachment-130\" class=\"wp-caption-text\">Fig. 1.17 Electricity generation in France: 549,6 TWh 18% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com<\/figcaption><\/figure>\n<h1>Germany &#8211; Energy System Overview<\/h1>\n<div>Energy generation in Germany is based on coal (43%), renevables (31%) nuclear Energy (13%) and gas (13%). <span style=\"text-align: left;color: #333333;text-indent: 0px;letter-spacing: normal;font-family: 'Montserrat',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;text-decoration: none;float: none;cursor: text;background-color: #ffffff\">Electricity Generation<\/span>: 642,9 TWh 31% renewables (IEA average: 24%).<br \/>\nThere are four transmission system operators (TSOs) in Germany. On 10 November 2017, there were 879 distribution system operators registered with the Federal Network Agency in Germany. Close to 800 of these DSOs operate networks with less than 100,000 connected costumers.<\/div>\n<div>German transmission system:<\/div>\n<ul>\n<li>Circuit Length \u2013 35,000 km,<\/li>\n<li>Voltage Level 400-380 kV \u2013 59%,<\/li>\n<li>Voltage Level 220-150 kV \u2013 41%,<\/li>\n<\/ul>\n<div>Strong connections of its system with neighbouring systems (AC 220kV, 380kV and under-sea HVDC lines).<\/div>\n<figure id=\"attachment_132\" aria-describedby=\"caption-attachment-132\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-132 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61946b0c76d.png\" alt=\"\" width=\"450\" height=\"449\" \/><figcaption id=\"caption-attachment-132\" class=\"wp-caption-text\">Fig. 1.18 Electricity generation in Germany 642,9 TWh 31% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<h1>Italy &#8211; Energy System Overview<\/h1>\n<p id=\"GTchtJC\">In Italy electric energy generation is based on thermal power plants (15% on coal, 42% on gas and 4% on heavy oil) and many types of renewables. <span style=\"text-align: left;color: #333333;text-indent: 0px;letter-spacing: normal;font-family: 'Montserrat',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;text-decoration: none;float: none;cursor: text;background-color: #ffffff\">Electricity Generation<\/span>: 284,1 TWh 39% renewables (IEA average: 24%).<br \/>\nThe only nuclear power plant in Italy was closed in 1987. As of 2018, Italy is one of only two countries, along with Lithuania, that completely phased out nuclear power for electricity generation after having operational reactors.<br \/>\nItalian transmission system:<br \/>\nCircuit Length \u2013 72,600 km,<br \/>\nVoltage Level 400-380 kV \u2013 19%,<br \/>\nVoltage Level 220-150 kV \u2013 81%,<br \/>\nConnected with neighbouring systems by AC 220kV, 380kV and under-sea HVDC lines.<\/p>\n<figure id=\"attachment_134\" aria-describedby=\"caption-attachment-134\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-134 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c619546f37a9.png\" alt=\"\" width=\"450\" height=\"449\" \/><figcaption id=\"caption-attachment-134\" class=\"wp-caption-text\">Fig. 1.19. Electricity generation in Italy: 284,1 TWh 39% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com<\/figcaption><\/figure>\n<h1>Poland &#8211; Energy System Overview<\/h1>\n<p>Currently (as at 31 December 2017) there are generating facilities with a net capacity totalling around 43,612 gigawatts (GW). Electricity Generation: 166,2 TWh 14% renewables (IEA average: 24%).<br \/>\nHowever, this capacity is not the same as the output available on the electricity market to meet demand at any given time, as the latter depends on the weather conditions. The supply is safeguarded almost entirely by conventional power plants.<br \/>\nIn 2017, conventional forms of energy generated 89,89 percent of electricity in Poland.<\/p>\n<figure id=\"attachment_137\" aria-describedby=\"caption-attachment-137\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-137 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c619616a912b.png\" alt=\"\" width=\"450\" height=\"449\" \/><figcaption id=\"caption-attachment-137\" class=\"wp-caption-text\">Fig. 1.20 Electricity generation in Poland: 166,2 TWh 14% renewables (IEA average: 24%). Source: IEA World Energy Balances 2017, www.next-kraftwerke.com<\/figcaption><\/figure>\n<p>As of 2016, there were 172 DSOs operating in Poland, and among them, five large DSOs belonging to vertically integrated undertakings. As these five DSOs are parts of vertically integrated undertakings they are subject to an obligation to separate distribution activities from generation operations or other economic activities of a vertically integrated undertaking (as a result of unbundling requirements).<\/p>\n<p style=\"text-align: center\">Tab. 1.1 Market share of Polish electricity companies. Source: Agora Energiewende, PTPiREE 2016<br \/>\n<img width=\"566\" height=\"399\" class=\"alignnone size-full wp-image-139 aligncenter\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c61966eae90e.png\" alt=\"\" \/><\/p>\n<p>Polish distribution networks are typical for Europe and they have got total length:<\/p>\n<ul>\n<li>110kV\u00a0lines \u2013\u00a033 300 km<\/li>\n<li>MV lines \u2013 296 920 km (6kV, 10kV, 15kV, 20kV, 30kV)<\/li>\n<li>LV lines \u2013 426 416 km<\/li>\n<\/ul>\n<p>Polish TSO \u2013 PSE performs the duties of the transmission system operator using its own transmission grid of the highest voltage, which consists of (2018):<\/p>\n<ul>\n<li>258 lines with a total length of 14\u00a0195 km, including:<br \/>\n&#8211; 1 line of 750kV voltage with a length of 114 km,<br \/>\n&#8211; 93\u00a0lines of 400kV voltage \u2013 6\u00a0326 km,<br \/>\n&#8211; 164 lines of 220kV voltage \u2013 7\u00a0755\u00a0km,<\/li>\n<li>106 extra-high voltage (EHV) substations<\/li>\n<li>under-sea 450kV DC connection between Poland and Sweden, with a total length of 254 km (127 km belongs to PSE).<\/li>\n<\/ul>\n<figure id=\"attachment_141\" aria-describedby=\"caption-attachment-141\" style=\"width: 546px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-141 size-full\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2019\/02\/img_5c619765205d5.png\" alt=\"\" width=\"546\" height=\"513\" \/><figcaption id=\"caption-attachment-141\" class=\"wp-caption-text\">Fig. 1.21. Transmission network development plan in Poland until 2025<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_727\" aria-describedby=\"caption-attachment-727\" style=\"width: 1048px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-727\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/PSE-plan-sieci.jpg\" alt=\"\" width=\"1048\" height=\"948\" \/><figcaption id=\"caption-attachment-727\" class=\"wp-caption-text\">Fig. 1.22. Transmission network and its development plan in Poland until 2027<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<h1><span style=\"color: #3366ff\">Energy mix of electricity generation and overall mix<\/span><\/h1>\n<p><span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">So far, we have discussed the energy mixes of electricity generation, for example Europe:<\/span><\/span><\/span><\/p>\n<p><strong><span style=\"color: #ff00ff\">4158 TWh\/year or 14969 PJ\/year<\/span><\/strong><\/p>\n<figure id=\"attachment_141\" aria-describedby=\"caption-attachment-141\" style=\"width: 716px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-141\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz.png\" alt=\"\" width=\"716\" height=\"358\" \/><figcaption id=\"caption-attachment-141\" class=\"wp-caption-text\">Fig. 1.22. Electricity generation by source<\/figcaption><\/figure>\n<p><span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">How does this mix differ from the overall energy mix?<\/span><\/span><\/span><\/p>\n<p><strong><span style=\"color: #ff00ff\">58909<\/span><span style=\"color: #ff00ff\"><strong> PJ\/y<\/strong>ear<\/span><\/strong><\/p>\n<figure id=\"attachment_141\" aria-describedby=\"caption-attachment-141\" style=\"width: 716px\" class=\"wp-caption aligncenter\"><img class=\"wp-image-141\" src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-1.png\" alt=\"\" width=\"716\" height=\"358\" \/><figcaption id=\"caption-attachment-141\" class=\"wp-caption-text\">Fig. 1.23. Total final energy consuption<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">And from total energy supply?<\/span><\/span><\/span><\/p>\n<p><strong><span style=\"color: #ff00ff\">81141<\/span><span style=\"color: #ff00ff\"><strong> PJ\/y<\/strong>ear<\/span><\/strong><\/p>\n<figure id=\"attachment_141\" aria-describedby=\"caption-attachment-141\" style=\"width: 738px\" class=\"wp-caption aligncenter\"><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-4.png\" width=\"738\" height=\"368\" alt=\"\" class=\"wp-image-1124 alignnone\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-4.png 737w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-4-300x150.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-4-65x32.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-4-225x112.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-4-350x175.png 350w\" sizes=\"(max-width: 738px) 100vw, 738px\" \/><figcaption id=\"caption-attachment-141\" class=\"wp-caption-text\">Fig. 1.23. Total energy supply<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><span class=\"HwtZe\" lang=\"en\"><span class=\"jCAhz ChMk0b\"><span class=\"ryNqvb\">And who consumes this energy?<\/span><\/span><\/span><\/p>\n<p><strong><span style=\"color: #ff00ff\">\u00a0<\/span><\/strong><\/p>\n<figure id=\"attachment_141\" aria-describedby=\"caption-attachment-141\" style=\"width: 728px\" class=\"wp-caption aligncenter\"><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-5.png\" width=\"728\" height=\"364\" alt=\"\" class=\"wp-image-1126 alignnone\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-5.png 734w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-5-300x150.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-5-65x33.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-5-225x113.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-5-350x175.png 350w\" sizes=\"(max-width: 728px) 100vw, 728px\" \/><figcaption id=\"caption-attachment-141\" class=\"wp-caption-text\">Fig. 1.24. Total final energy consumption<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<h1><span style=\"color: #ff6600\">Some additional charts to study for yourself &#8211; how the energy mixes are changing<br \/>\n<\/span><\/h1>\n<h1><span style=\"color: #ff6600\">POLAND<\/span><\/h1>\n<p><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10.png\" width=\"710\" height=\"395\" alt=\"\" class=\"wp-image-1132 aligncenter\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10.png 960w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10-300x167.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10-768x428.png 768w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10-65x36.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10-225x125.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-10-350x195.png 350w\" sizes=\"(max-width: 710px) 100vw, 710px\" \/><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8.png\" width=\"729\" height=\"403\" alt=\"\" class=\"wp-image-1130 aligncenter\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8.png 960w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8-300x166.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8-768x425.png 768w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8-65x36.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8-225x124.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-8-350x194.png 350w\" sizes=\"(max-width: 729px) 100vw, 729px\" \/><\/p>\n<p><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6.png\" width=\"723\" height=\"400\" alt=\"\" class=\"wp-image-1128 aligncenter\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6.png 960w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6-300x166.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6-768x425.png 768w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6-65x36.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6-225x124.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-6-350x194.png 350w\" sizes=\"(max-width: 723px) 100vw, 723px\" \/><\/p>\n<h1><span style=\"color: #ff6600\">GERMANY<\/span><\/h1>\n<p><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11.png\" width=\"793\" height=\"438\" alt=\"\" class=\"wp-image-1133 aligncenter\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11.png 960w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11-300x166.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11-768x424.png 768w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11-65x36.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11-225x124.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-11-350x193.png 350w\" sizes=\"(max-width: 793px) 100vw, 793px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13.png\" width=\"779\" height=\"431\" alt=\"\" class=\"wp-image-1135 aligncenter\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13.png 960w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13-300x166.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13-768x426.png 768w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13-65x36.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13-225x125.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-13-350x194.png 350w\" sizes=\"(max-width: 779px) 100vw, 779px\" \/><\/p>\n<h1><span style=\"color: #ff6600\">FRANCE<\/span><\/h1>\n<p><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14.png\" width=\"770\" height=\"426\" alt=\"\" class=\"wp-image-1136 aligncenter\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14.png 960w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14-300x166.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14-768x426.png 768w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14-65x36.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14-225x125.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-14-350x194.png 350w\" sizes=\"(max-width: 770px) 100vw, 770px\" \/><\/p>\n<p><img src=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15.png\" width=\"798\" height=\"442\" alt=\"\" class=\"wp-image-1137 aligncenter\" srcset=\"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15.png 960w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15-300x166.png 300w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15-768x426.png 768w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15-65x36.png 65w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15-225x125.png 225w, http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-content\/uploads\/sites\/9\/2018\/12\/obraz-15-350x194.png 350w\" sizes=\"(max-width: 798px) 100vw, 798px\" \/><\/p>\n<h1>Questions<\/h1>\n<p>1. What is the power system?(present different approaches)<br \/>\n2. What are the basic elements of power system? (give description)<br \/>\n3. What is the difference between electric power system and other economy systems?<br \/>\n4. What are typical voltage levels for transmission and\u00a0distribution?<br \/>\n5. What are the levels of electric power system? (give description)<br \/>\n6. What are the most important parameters of electric power system operation?<br \/>\n7. What is ENTSOE?<br \/>\n8. Describe difference between: installed power of system, maximum capacity and available capacity.<br \/>\n9. Which voltage level network has the largest total length?<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"author":7,"menu_order":1,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"part":20,"_links":{"self":[{"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/pressbooks\/v2\/chapters\/28"}],"collection":[{"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/wp\/v2\/users\/7"}],"version-history":[{"count":55,"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/pressbooks\/v2\/chapters\/28\/revisions"}],"predecessor-version":[{"id":59,"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/pressbooks\/v2\/chapters\/28\/revisions\/59"}],"part":[{"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/pressbooks\/v2\/parts\/20"}],"metadata":[{"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/pressbooks\/v2\/chapters\/28\/metadata\/"}],"wp:attachment":[{"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/wp\/v2\/media?parent=28"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/pressbooks\/v2\/chapter-type?post=28"},{"taxonomy":"contributor","embeddable":true,"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/wp\/v2\/contributor?post=28"},{"taxonomy":"license","embeddable":true,"href":"http:\/\/pb.ee.pw.edu.pl\/pb\/iepe\/wp-json\/wp\/v2\/license?post=28"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}