The paper presents an analysis of the influence of the energy generated from renewable sources on an improvement in the energy efficiency of public utility building and households. It also presents the current state of the technologies for the production of electricity from renewable sources, as well as their share in the national power supply system. The conducted analysis concerns both micro, as well as large systems generating electricity. Systems generating power from renewable sources are gaining in popularity. With an increasing awareness in the society of the beneficial influence that renewable power generating systems have on the environment, as well as the support in form of various programs offering subsidies for the construction of new systems, power generation from renewable sources is becoming increasingly popular and common. Although the renewable energy systems are still not widely considered to be a profitable solution, systems using renewable sources of energy are positively perceived and treated as a new trend in the construction of multi or single-family residential buildings. The increasing share of the renewable energy in the national power supply system significantly reduces the demand for energy produced from conventional sources. This obviously translates into a reduced consumption of primary energy, for example, fossil fuels, and, in turn, leads to the reduced exploitation of natural resources, thus contributing to the protection of the natural environment. A reduced consumption of fossil fuels also means a significant reduction in environmental pollution during their processing into electricity or heat. Actions aiming at improving energy efficiency and reducing final energy consumption are being undertaken by many countries all over the world, and by the European Union. In 2012, the European Parliament and the Council issued Directive 2012/27/EU obliging the Member States to initiate actions aiming at a reduction in the consumption of final energy by 1.5% a year. The paper presents the current status of generation of energy from renewable sources during the last 13 years. The ways for using energy from the renewable sources to improve the energy efficiency of facilities were also discussed.
The paper presents an analysis of energy and economic effectiveness of the combined heat and power (cogeneration) technologies fired with natural gas that may be deemed prospective for the Polish electric power system. The current state of the cogeneration technologies fired with natural gas in Poland is presented. Five cogeneration technologies fired with natural gas, prospective from the point of view of the Polish electric power system, were selected for the analysis. Namely, the paper discusses: gas-steam combined heat and power (CHP) unit with 3-pressure heat recovery generator (HRSG) and steam interstage reheat, gas-steam CHP unit with 2-pressure HRSG, gas-steam CHP unit with 1-pressure HRSG, gas CHP unit with small scale gas turbine, operating in a simple cycle and gas CHP unit with gas engine. The following quantities characterizing the energy effectiveness of the cogeneration technologies were selected for the analysis: electricity generation efficiency, heat generation efficiency, primary energy savings (PES) and CO2 unit emission. The economic effectiveness of particular technologies was determined based on unit electricity generation costs, discounted for 2019, including the costs of purchasing CO2 emission allowances. The results of calculations and analyses are presented in a table and on a figures.
The paper presents an analysis of the sustainable development of electricity generation sources in the National Power System (NPS). The criteria to be met by sustainable power systems were determined. The paper delineates the power balance of centrally dispatched power generation units (CDPGU), which is required for the secure work of the NPS until 2035. 19 prospective electricity generation technologies were defined. They were divided into the following three groups: system power plants, large and medium combined heat and power (CHP) plants, as well as small power plants and CHP plants (distributed sources). The quantities to characterize the energy effectiveness and CO2 emission of the energy generation technologies analyzed were determined. The unit electricity generation costs, discounted for 2018, including the costs of CO2 emission allowance, were determined for the particular technologies. The roadmap of the sustainable development of the generation sources in the NPS between 2020 and 2035 was proposed. The results of the calculations and analyses were presented in tables and figure