Review-based Emergy Analysis of Energy Production

The role of power and thermal energy is impossible to overestimate in development of both state economy sector and everyday life of households. Importance is connected with use of resources, economical feasibility and effect to climate changes. The optimization of energy production allows to promote development of sustainable society. The most popular and efficient technologies for generation of power and thermal energy are cogeneration plants (CHP). Traditional evaluation methodologies of energy production systems are based on analysis of energy and mass balances as well as on cost analysis. It is not enough for assessment of complete sustainability of system. Necessary environmental impact assessment of energy production is possible to implement by use of emergy analysis. Definition of emergy includes one type of energy, which is used directly or indirectly to produce materials, provide services and finances. Emergy dimension is emjoules (seJ.). Paper presents case study of emergy analysis of different operation modes of one cogeneration plant

Top energy saver of the year : results of an energy saving competition in public buildings

Non-residential buildings in the European Union consume more than one third of the building sector's total. Many non-residential buildings are owned by municipalities. This paper reports about an energy saving competition that was carried out in 91 municipal buildings in eight EU member states in 2019. For each public building an energy team was formed. The energy teams' activities encompassed motivating changes in the energy use behaviour of employees and small investments. Two challenges added an element of gamification to the energy saving competition. To assess the success of the energy saving competition, an energy performance baseline was calculated using energy consumption data of each public building from previous years. Energy consumption in the competition year was monitored on a monthly base. After the competition the top energy savers from each country were determined by the percentage-based reduction of energy consumption compared to the baseline. On average, the buildings had an electricity and heat consumption in 2019 that was about 8 % and 7 %, respectively, lower than the baseline. As an additional data source for the evaluation, a survey among energy team members was conducted at the beginning and after the energy competition. Support from superiors, employee interest and motivation and behaviour change as assessed by energy team members show a positive, if weak or moderate, correlation with changes in electricity consumption, but not with changes in heat consumption

Increasing Sustainability in Vocational Education System: Latvia Case Study

Promoting sustainability in educational systems is crucial for preserving resources and diminishing negative impacts on the environment. A key aspect of this is enhancing energy efficiency within educational institutions. By implementing energy-efficient building systems, advancing the use of renewable energy sources, and incorporating sustainable practices into the curriculum, educational institutions can decrease their environmental impact and conserve resources for future generations. Active participation from all stakeholders, including managers, teaching staff, and students, is essential for the success of these efforts. Providing students with a comprehensive education on sustainability equips them to apply this knowledge in their future professions, thus contributing to a more sustainable society. This research paper aims to explore ways to increase sustainability in Latvia's vocational education system, with a specific focus on reducing energy consumption in buildings and increasing the use of renewable energy sources. A study of 23 professional schools has been conducted to understand the current state of sustainability in the educational system, including data collection on energy consumption and surveying the schools on their current energy efficiency practices, renewable energy sources, and environmental policies. The energy efficiency and renewable energy production measures have been optimized for each school. A composite indicator has been developed to rank and compare schools based on their sustainability, promoting the use of energy-efficient and renewable energy sources within a limited budget. Results of the study show that by implementing mandatory and optional measures, the schools can significantly decrease primary energy consumption by 32% and greenhouse gas emissions by 33%

Gas Condensing Unit with Inner Heat Exchanger

Gas condensing units with inner tubes heat exchangers represent third generation technology and differ from second generation heat and mass transfer units, which are fulfilled by passive filling material layer. The first one improves heat and mass transfer by increasing cooled contact surface of gas and condensate drops and film formed in inner tubes heat exchanger. This paper presents a selection of significant factors which influence the heat and mass transfer. Experimental planning is based on the research and analysis of main three independent variables; velocity of water and gas as well as density of spraying. Empirical mathematical models show that the coefficient of heat transfer is used as dependent parameter which depends on two independent variables; water and gas velocity. Empirical model is proved by the use of experimental data of two independent gas condensing units in Lithuania and Russia. Experimental data are processed by the use of heat transfer criteria-Kirpichov number. Results allow drawing the graphical nomogram for the calculation of heat and mass transfer conditions in the innovative and energy efficient gas cooling unit

Analysis of Energy Supply Solutions of Dwelling Buildings

Individual heating consumption for dwelling buildings has an important part in Latvia’s energy balance. Increasing energy efficiency and reducing primary energy in the household sector can play a role in national energy targets. This paper analyses three different heating systems which focus on a pellet boiler and solar collector combined system. The performance of existing solar collectors is analysed and the solar collector system performance ratio is determined. Costs including investments, fuel and maintenance have been analysed and a comparison between systems is made using the indicator – costs per produced energy. Results show that the performance of the solar collector system should be increased or investments should decrease to meet the cost effectiveness of other analysed heating systems

Treatment of Particulate Matter Pollution: People’s Attitude and Readiness to Act

The paper displays results of the questionnaire called “Particulate matter pollution in air”, which serves as a tool to determine level of public awareness of the health risks related to pollution from small capacity heating equipment in households. Barriers for installation of the innovative flue gas treatment technology called a fog unit in households and possible mechanisms to decrease or prevent these barriers were defined. The first part of the questionnaire included overall information about participants: age, gender, education level, place of residence, activities to protect the environment and motives behind performing these activities. The remaining questions were divided in four groups: “Environmental views”, “Knowledge on air pollution”, “Willingness to pay”, “Choice of flue gas treatment technologies”. The results of questionnaire correspond with raised problem situations. Over 80 % of respondents lack information on pollution and possible consequences deriving from it, and on potential solutions to prevent pollution. Residents of households are willing to pay for installation of flue gas treatment equipment (capital investments)

Modelling of Technological Solutions to 4th Generation DH Systems

Flue gas evaporation and condensing processes are investigated in a direct contact heat exchanger - condensing unit, which is installed after a furnace. By using equations describing processes of heat and mass transfer, as well as correlation coherences for determining wet gas parameters, a model is formed to create a no-filling, direct contact heat exchanger. Results of heating equipment modelling and experimental research on the gas condensing unit show, that the capacity of the heat exchanger increases, when return temperature of the district heating network decreases. In order to explain these alterations in capacity, the character of the changes in water vapour partial pressure, in the propelling force of mass transfer, in gas and water temperatures and in the determining parameters of heat transfer are used in this article. The positive impact on the direct contact heat exchanger by the decreased district heating (DH) network return temperature shows that introduction of the 4th generation DH system increases the energy efficiency of the heat exchanger. In order to make an assessment, the methodology suggested in the paper can be used in each particular situation

Top Energy Saver of the Year: Results of an Energy Saving Competition in Public Buildings

Non-residential buildings in the European Union consume more than one third of the building sector's total. Many non-residential buildings are owned by municipalities. This paper reports about an energy saving competition that was carried out in 91 municipal buildings in eight EU member states in 2019. For each public building an energy team was formed. The energy teams' activities encompassed motivating changes in the energy use behaviour of employees and small investments. Two challenges added an element of gamification to the energy saving competition. To assess the success of the energy saving competition, an energy performance baseline was calculated using energy consumption data of each public building from previous years. Energy consumption in the competition year was monitored on a monthly base. After the competition the top energy savers from each country were determined by the percentage-based reduction of energy consumption compared to the baseline. On average, the buildings had an electricity and heat consumption in 2019 that was about 8 % and 7 %, respectively, lower than the baseline. As an additional data source for the evaluation, a survey among energy team members was conducted at the beginning and after the energy competition. Support from superiors, employee interest and motivation and behaviour change as assessed by energy team members show a positive, if weak or moderate, correlation with changes in electricity consumption, but not with changes in heat consumption