In this paper, the results of correlations between air temperature and electricity demand by linear regression and Wavelet Coherence (WTC) approach for three different European countries are presented. The results show a very close relationship between air temperature and electricity demand for the selected power systems, however, the WTC approach presents interesting dynamics of correlations between air temperature and electricity demand at different time-frequency space and provide useful information for a more complete understanding of the related consumption.
Time-of-use (TOU) electricity pricing has been applied in many countries around the world
to encourage manufacturers to reduce their electricity consumption from peak periods to
off-peak periods. This paper investigates a new model of Optimizing Electricity costs during
Integrated Scheduling of Jobs and Stochastic Preventive Maintenance under time of-use
(TOU) electricity pricing scheme in unrelated parallel machine, in which the electricity price
varies throughout a day. The problem lies in assigning a group of jobs, the flexible intervals
of preventive maintenance to a set of unrelated parallel machines and then scheduling of jobs
and flexible preventive maintenance on each separate machine so as to minimize the total
electricity cost. We build an improved continuous-time mixed-integer linear programming
(MILP) model for the problem. To the best of our knowledge, no papers considering both
production scheduling and Stochastic Preventive Maintenance under time of-use (TOU) electricity
pricing scheme with minimization total Electricity costs in unrelated parallel machine.
To evaluate the performance of this model, computational experiments are presented, and
numerical results are given using the software CPLEX and MATLAB with then discussed.
Ensuring the security of power generation systems is a pillar of the proper functioning of each state. Energy security is fundamental to ensure both economic growth and social welfare. As energy storage has not developed in an efficient extent, covering the current and prospective power demand is a major challenge for transmission system operators. Moreover, the activities that are to be taken should be technically and economically justified and need to meet the requirements of environmental protection. Cooperation between neighboring countries in the field of electricity exchange is among the activities undertaken to ensure the safety of the power generation systems. The integration of electricity markets is one of the key challenges of the European Union’s energy policy. The European Commission issued a directive on interconnection, according to which the capacity of interconnections should total 10% of installed capacity until 2020 (and 15% until 2030) in each Member State. The main objective of this study is to assess the changes in electricity imports and exports in 2003–2018 and to investigate the current level of cross-border exchanges between Poland and the neighboring countries. This paper also answers the question of whether Poland will fulfil the obligations set by the European Commission. In addition, the paper presents the risks and the challenges related to fulfilling the mentioned commitments. The results of the study indicate that the development and modernization of network infrastructure in the field of cross-border exchange are necessary because, in the context of the forecasted increase in electricity demand, Polish generation units will not be able to meet the demand.
In this paper, selected aspects of the national technical level of electric energy supply security is shown. An analysis and assessment of the electric power infrastructure in area of generation, transmission and distribution in aspects of electric energy security is conducted. The profile of the generation sector and grid infrastructure in the area of transmission and distribution is shown. The present and future situation in a range of operation of electric power infrastructure in the area of generation, transmission and distribution in the frames of the National Electric Power System in the electric energy supply security context is determined. The level of national electric energy supply security in area of generation and grid infrastructure is assessed. Threats of electric energy supply security are described and the catalogue of essential actions for the assurance of electric energy supply security are proposed. In the area of electricity generation, at present there is no danger to the electricity supply security in normal load conditions, but there is a high probability that it will occur in the future (after 2025) when the forecasted increase in electricity demand takes place and the new stringent environment protection requirements (Directive IED, BAT conclusions, Winter Package) enter into force. The network infrastructure in area of transmission and distribution is admittedly adapted for presently occurred typical conditions of electric energy demand and the realization of internal tasks in normal conditions, but can create a potential threat for electric energy supply security. In the context of the forecasted increase of electric energy demand, inadequate power generation sources in the National Electric Power System and available through intersystem connections, their uneven location on the territory of Poland in the shortage of proper network transmission capacities, the necessity of improvement of the quality and electric energy supply reliability to final consumers and the intensive development of renewable energy sources, the present network infrastructure in area of transmission and distribution will be insufficient.
This article describes a thermodynamic analysis of an oxy type power plant. The analyzed power plant consists of: 1) steam turbine for supercritical steam parameters of 600 °C/29 MPa with a capacity of 600 MW; 2) circulating fluidized bed boiler, in which brown coal with high moisture content (42.5%) is burned in the atmosphere enriched in oxygen; 3) air separation unit (ASU); 4) CO2 capture installation, where flue gases obtained in the combustion process are compressed to the pressure of 150 MPa. The circulated fluidized bed (CFB) boiler is integrated with a fuel dryer and a cryogenic air separation unit. Waste nitrogen from ASU is heated in the boiler, and then is used as a coal drying medium. In this study, the thermal efficiency of the boiler, steam cycle thermal efficiency and power demand were determined. These quantities made possible to determine the net efficiency of the test power plant.
The increasingly stringent requirements for wastewater treatment enforce the adoption of technologies that reduce pol-lution and minimize waste production. By combining the typical activated sludge process with membrane filtration, biolog-ical membrane reactors (MBR) offer great technological potential in this respect. The paper presents the principles and ef-fectiveness of using an MBR at the Głogów Małopolski operation.Physicochemical tests of raw and treated wastewater as well as microscopic analyses with the use of the FISH (fluorescence in situ hybridization) method were carried out. More-over, the level of electric energy consumption during the operation of the wastewater treatment plant and problems related to fouling were also discussed. A wastewater quality analysis confirmed the high efficiency of removing organic impurities (on average 96% in case of BOD5 and 94% in case of COD) and suspension (on average 93%).
The paper presents the characteristics of the attitude that students have towards electric cars and the significance of distinguished attitude elements in creating interest in the purchase of such vehicles. Electric cars are the new type of vehicles that have an electric motor and use the electricity stored in batteries. They are introduced to the market, but for various reasons the volume of sales is not high. So far, it is not sufficiently known how electric vehicles are assessed by Poles. The presented research is an attempt to know what the attitude towards this type of vehicle. The attitude model tested in this research includes three areas: knowledge about them, emotions that they evoke and potential behaviors. The participants were students of Rzeszów University of Technology – a group of young people who are potential consumers of new technologies. The obtained results indicate that electric cars are rather unknown. At the same time, they arouse great interest and their image is very positive. The attitude characteristics towards this type of vehicle is supplemented by perceived limitations: too high of a purchase price, lack of sufficient information about them and unsatisfactory technical parameters, mainly the long time needed to recharge the battery and the insufficiently long distance with one recharge. The interest in the purchase is dependent on positive emotions, and the lack of sufficient information is an obstacle in thinking about buying such a vehicle. Understanding the attitudes of Polish students towards electric cars can be helpful in adapting information about such cars to potential customers, which in turn may affect the level of interest and sales volume.
Energy is a basic industry for any economy and ensures the country’s security, including economic
security. The purpose of the article is to analyze the reform of the energy sector in Ukraine
for successful integration into the energy sector of the European Union. The state of the energy
industry from 2003 to 2018 is analyzed. The following main reasons for the decrease in electricity
generation in Ukraine are identified – a decrease in production volumes, the annexation of Crimea
and the anti-terrorist operation in the east of Ukraine, a decrease in the volume of energy output
from Thermal Power Plants due to aging capacities, difficulties with raw materials, low efficiency,
which, however, has a good effect on the environment due to a decrease carbon dioxide emissions.
The directions of reforming the electric power industry of Ukraine are considered in the context of
“industry-market-company”. Four electricity market models are analyzed and the new model of the
competitor’s market for electricity in Ukraine with contract market, spot market, the balancing market
is substantiated. The structure of the segments of the new electricity market and the participants
are proposed. More than half of the electricity market is provided by nuclear power, which ranks
the 5th in the world in terms of installed capacity. The analysis of the performance indicators of the
nuclear company for 2007–2019 showed significant reserves for the company’s growth, which are
being successfully implemented through strategic development projects and phased corporatization
of the company as a tool of unbundling. The main challenges of implementation a new market
model are analyzed and solutions are proposed.
The paper looks at an analysis of the tendency of changes in the fuel structure of electricity
generation and thus resulting changes in carbon dioxide emissions. Forecasts drawn up by various
institutions and organizations were selected for the analysis. Firstly, on the basis of statistical data
contained in (IEA 2017a, IEA 2008) and with the use of Kay’s indicators, the impact of changes in
energy intensity of the national income and energy mix on changes in carbon dioxide emissions per
capita in 2006–2015 for the OECD countries and Poland were analyzed. A small effect of changes
was found in the fuel mix in this period of time on the emissions. The main impact was due to changes
in the energy intensity of the national income and changes in the national income per capita.
Next, selected fuel scenarios for the period up to 2050 (60) were discussed – WEC, IEA, EIA, BP,
Shell, with a focus on the WEC scenarios. These have been developed for various assumptions with
regard to the pace of economic development, population growth, and developments of the political
situation and the situation on the fuel market. For this reason, it is difficult to assess the reliability
thereof. The subject of the discussion was mainly the data on the fuel structure of electricity generation
and energy intensity of national income and changes in carbon dioxide emissions. The final
part of the paper offers a general analysis of forecasts drawn up for Poland. These are quite diverse,
with some of them being developed as part of drawing up the Energy Policy for Poland until 2050,
and some covering the period up to 2035. An observation has been made that some forecasts render
results similar to those characteristic of the WEC Hard Rock scenario.
The progressive processes of globalization and changes in the global, European and local economy require integrated efforts aimed at solving problems related to development at the national regional and the local level involving the environment, energy sources, climate and technological transformation issues. European Union Member States are given right to create an individual Energy mix. Coal will continue to play a major role in Poland’s energy mix during the next decades. Polish coal reserves can provide energy security for decades.
Despite crude oil and natural gas growth in fuel consumption, coal will continue to be the stabilizer of energy security for the country and play an important role in Poland’s energy mix in the years to come. However, further coal consumption requires investments in low carbon technologies which are of high efficiency and in high-efficiency cogeneration.
The validity of the full utilization of cogeneration potential should be highlighted. Operating cogeneration plants are more expensive than power plants but they are more efficient and generate less carbon emissions. In accordance with the assumptions of the Energy policy of Poland, a low-carbon economy with renewable Energy sources and nuclear Energy should be supported and developed, however the obsolete coal generators should be replaced with low-carbon high-efficient ones.
Within this study, resonance phenomenon, which is one of the crucial problems in mechanical constructions, has been analyzed with respect to oil starvation failure in a ball bearing. A unique test rig is designed, constructed, and placed in a laboratory ambience. A ball bearing on the electrical motor, which is a component of the test rig, has been selected for acquisition of data within triple sensing technology in vibration, acoustic, and electrical consumption through testing conditions. The target of that study is condition monitoring of oil starvation fault and resonance fault for comparison of various predictive maintenance methods. The testing was carried out within the electrical frequency of 40.5 Hz, which actuated the electrical motor in order to identify the rotation speed. According to the analyzed results, oil starvation fault and resonance fault is most accurately inspected by vibration analysis.
For the purpose of making of a solid body of an electric guitar the acoustic- and mechanical properties of walnut- (Juglans regia L.) and ash wood (Fraxinus excelsior L.) were researched. The acoustic properties were determined in a flexural vibration response of laboratory conditioned wood elements of 430 × 186 × 42.8 mm used for making of a solid body of an electric guitar. The velocity of shearand compression ultrasonic waves was additionally determined in parallel small oriented samples of 80 × 40 × 40 mm. The research confirmed better mechanical properties of ash wood, that is, the larger modulus of elasticity and shear modules in all anatomical directions and planes. The acoustic quality of ash wood was better only in the basic vibration mode. Walnut was, on the other hand, lighter and more homogenous and had lower acoustic- and mechanical anisotropy. Additionally, reduced damping of walnut at higher vibration modes is assumed to have a positive impact on the vibration response of future modelled and built solid bodies of electric guitars. When choosing walnut wood, better energy transfer is expected at a similar string playing frequency and a structure resonance of the electric guitar.