• Energy Research
• Closed Access close
• Open Source close
• PL close
• SDSN Greece close

For economic reasons, expansions of transmission networks are based on a compromise between capital cost and security of power system operation. At the same time, the power system must withstand typical highly likely contingencies. Various emergency state control systems, also called special protections, prevent emergencies following less likely contingencies. This paper describes overloads emergency state control (OLEC) used for the alleviation of overload in transmission networks near a power plant. Such control uses the functions of automated power reduction of generating units and has been implemented for a large steam power plant. The OLEC presented here uses different methods of generation curtailment for steam generation units. A case study illustrates the efficiency of the proposed control method.

Abstract Coal gasification is accompanied with formation of tars that cause equipment problems and have to be removed from the raw gas. Our previous studies proved that nickel supported ceria-zirconia catalyst (Ni/CZ) reveals high activity towards decomposition of toluene and 1-methylnaphthalene (1-MN) via steam reforming reaction (SR). However, the components of the raw gas from coal gasification (i.e. H2, CO, CO2 and CH4) may influence the performance of Ni/CZ catalyst. The influence of particular components of the raw gas on catalyst performance during SR of model tar compounds have been studied and discussed in this paper. It has been found that H2 and CO addition to the steam reforming feed drastically decreases the activity of Ni/CZ catalyst, whereas CO2 presence enhances conversion of toluene and 1-MN mixture owing to the occurrence of dry reforming reaction (DR). It has also been observed that methane, which is present in the raw gas from coal gasification consumes partly both the H2O and CO2, causing some decrease in conversion of model tar compounds. The influence of contact time (tc) on hydrocarbons conversion and the participation of (DR) have been examined. As was observed, lower contact times lead to decrease in hydrocarbons conversion in SR, making the same participation of DR more pronounced than for higher tc values. This work proves that Ni/CZ catalyst can be used for removal of tarry compounds via the catalytic hot gas cleaning of the raw gas form coal gasification.

Abstract Grape pomace is a by-product of the wine making industry with great availability and energetic potential. Torrefaction is a pre-treatment that may enhance the biomass quality as a fuel, and consists in exposing the biomass to an inert atmosphere at a temperature between 200 °C and 300 °C. This study evaluates the combustion characteristics of raw and torrefied grape pomace in a thermogravimetric analyzer and in a drop tube furnace. Initially, the raw grape pomace was torrefied in an argon inert atmosphere at 260 °C. Subsequently, the combustion of the raw and torrefied grape pomace was examined in the thermogravimetric analyzer through non-isothermal runs at a heating rate of 10 °C/min from room temperature to 800 °C. Finally, the combustion of both biomass residues was evaluated in the drop tube furnace at 1100 °C. The data reported includes gas temperature, major gas species concentration and particle burnout measured along the axis of the drop tube furnace. The main conclusions of this study are (i) for the devolatilization stage, the thermogravimetric data yielded apparent activation energy values of 84.9 and 85.2 kJ mol−1, and for the char oxidation stage of 137.5 and 109.2 kJ mol−1 for the raw and torrefied grape pomace, respectively; (ii) the NOx concentrations along the drop tube furnace were always higher for the combustion of the torrefied grape pomace than for the combustion of the raw grape pomace because the former residue has a higher nitrogen content; and (iii) the burnout values along the drop tube furnace were always lower for the combustion of the torrefied grape pomace than for the combustion of the raw grape pomace because the former residue has a lower volatile content and a higher fixed carbon content.

Abstract The transportation of liquefied natural gas by sea has a strategic function for ensuring the energy security of Poland and, in a broader perspective, also of the countries in the Central and Eastern Europe region (primarily the Visegrad Group - V4 and others). The article points out the importance of Polish LNG/FSRU terminals in diversification and building the region's energy independence. It analyzes the security environment of the Baltic coastal waters, which is the arena for the activity of many countries with different multidimensional interests. A package of threats to maritime critical infrastructure facilities (LNG/FSRU terminals) and cryogenic tankers in the air, surface, and underwater domains is identified, noting the dynamic nature of many of them. The author analyzes the capabilities (strengths and weaknesses) of autonomous maritime systems (USV, UUV-ROV, UAV) in terms of their use to increase the effectiveness of LNG/FSRU terminal security systems. Possibilities of cooperation and achieving a synergy effect within the combined architecture of USV/UUV-ROV/UAV platforms are also indicated. The article presents a package of missions that autonomous systems can perform to increase the safety of operators and reduce the response time to threats, thus increasing the level of protection. The article presents a vision of a modular USV base platform model as a base element for an autonomous system dedicated to protecting LNG terminal/FSRU infrastructure and cryogenic tankers.

Abstract In the summer of 1989 a survey was conducted to collect data on household-energy consumption in Indian cities. The survey was conducted in three urban areas of varying sizes. The end-uses considered were cooking, water heating, lighting, air cooling, entertainment, cold storage, and washing/laundry. The surveys involved examination of the types and quantities of energy used to satisfy each of these services. The survey sample in each of the three cities was broken down by income group, allowing for a careful examination of the influence of household income on lifestyle patterns and related energy use choices. Among the houses surveyed were 75 households in Pune, India, that took part in a 1982 household energy study as well. The re-surveying process allowed for an analysis of longitudinal changes in residential energy use. Based on the survey findings, a number of recommendations are provided for improving the provision and use of energy in urban households in India.

Abstract Biomass integrated gasification cogeneration is nowadays considered as one of the most attractive technologies for CO 2 emission reduction and non-renewable fuel savings. The paper presents application of the Thermo-Ecological Cost (TEC), which expresses the cumulative consumption of non-renewable exergy, for examination of energy and environmental benefits of biomass energy conversion plant based on gasification technology and medium scale recuperative gas turbine. To express the total effect of considered energy conversion systems the TEC is supplemented with the data resulting from Life Cycle Analysis (LCA). Different available gasification technologies and configurations of a cogeneration plant are investigated. Atmospheric fluidized bed gasification (AFB), pressurized fluidized bed gasification (PFB) and allothermal gasification using pure steam as gasification agent (FICFB) are taken into account as well as simple and combined power cycles with the Mercury 50 Solar gas turbine. The results reveal that simple cycle with gas turbine and waste heat recovery water boiler offers better effects than combined cycle configuration. The best performance has been reported for pressurized gasification technology.

Abstract Lithium-ion battery systems are becoming a major component in numerous applications. The thermal behaviour of cells should be monitored for many reasons. In this paper, the investigation of the energy balance for lithium-ion battery system is described. The electrothermal model allows to describe heat generation and heat dissipation processes in all components of a battery pack (BP). Moreover, this model can be easily adapted for bigger, modular battery systems, since the primitive in the proposed model is a single cell. A method to determine the energy balance through experimental investigations and to validate the model is also proposed. Four types of BPs with sixteen cylindrical 18650 lithium-ion cells were tested. The influence of both busbar material and the presence of heatsinks on the BP thermal conditions was investigated. The results show that the heat accumulated in cells can be decreased by 20% and the cell temperature lowered by 8 °C if additional elements are used in a BP.

© 2021 Elsevier LtdDespite extensive research to address the impact of environmental reforms under the Paris Climate Agreement, current literature has failed to provide sufficient insights into Regional Comprehensive Economic Partnership (RCEP) countries. To this end, the current study attempts to address the impact of the economic complexity on environmental quality in the presence of renewable energy consumption, financial development, urbanization and energy innovation in RCEP countries from 1990 to 2019. Our empirical estimates confirm a significant association between environmental quality, economic complexity index, renewable energy consumption, financial development, urbanization and energy innovation in the short-run and long run. Based on extensive econometric analysis (CS-ARDL, AMG, PMG, FMOLS, and DOLS), we conclude that economic complexity, renewable energy, and energy innovation effectively mitigate environmental degradation. At the same time, financial development and urbanization have an adverse impact on the environment. These findings have extensive policy implications for policymakers and environmental stakeholders, who are aiming to achieve sustainable energy policy and economic growth to meet the environmental commitments under Paris Climate Agreement.

Abstract The paper presents a comprehensive approach to capturing the scale of exposure to hidden energy poverty at a household level in 11 Central and Eastern European countries. Despite constant refinements, the currently used energy poverty metrics remain highly controversial when it comes to inter-country comparisons. Scarce data and the lack of agreement on the energy poverty definition among the EU countries impedes operationalization of energy poverty measures on a global scale. Instead, we propose a reliable tool for tracking hidden energy poverty based on the existing micro-level data compiled by Eurostat. The paper assumes that the energy poor limit their energy consumption to the level below what is reasonably assumed a decent life. To estimate the expected energy costs, the paper introduces a new statistical approach. We consider multiple aspects of exposure to hidden energy poverty, including dwelling parameters and location, households’ structure, and regional specificity. Our findings confirm that on average 23.57% of the Central and Eastern European population is exposed to hidden energy poverty. The examined profiles are quite heterogeneous. In general, the affected are single-person households or living in detached houses and remote areas households with dependent children. The paper provides suggestions for targeted policy action.