ALBERT

Description: The aim of this review article is the analysis of the results obtained from the scientific literature concerning all the phases that make up the life cycle of traction batteries for electric vehicles, in order to evaluate the associated environmental impact. In this regard, some scientific articles dealing with LCA studies concerning electric vehicles, with particular reference to batteries, will be examined. The revision of these articles will provide a general framework for the production, use and recycling phases of traction batteries. In particular, different parameters that influence the outcome of the LCA studies will be shown, parameters on which we can then act to improve the environmental impacts of the transition from internal combustion vehicles to electric mobility. These parameters are represented by the chemistry of the battery considered, aspect at the centre of the discussion, by the specific energy and efficiency of the battery pack, by the durability of the latter, but also by other aspects, such as the energy mix considered (both for the production phase, for the use phase and for recharging) and the functional unit chosen for the study, which determines a different approach, related to the analysis of a specific problem or aspect rather than another. Finally, the usefulness of the recycling practice and the related problems will be shown. In fact, the recycling must be perfected according to the battery chemistry in question to obtain benefits and better reduce environmental loads.

Description: It is the responsibility of each member state of the European Union, to prepare a national energy and climate plan and set achievable climate targets and meaningful measures and policies to achieve the targets set. Annex 4 of the Latvian National Energy and Climate Plan for 2030 (hereinafter – NECP) provides an overview of policies and measures to achieve the climate targets. The NECP does not provide information on the impact of the policies or which measures are more important and which are less crucial Similarly, the measures in Annex 4 of the NECP were not determined by industry experts but by ministry officials, therefore, it is not clear whether the proposed measures will achieve the set climate targets, a point also made by European Commission in its evaluation report on NECP. The aim of the study is to develop a tool for the early assessment of the impact of energy and climate policy measures. The study developed a methodology to pre-assess the impacts of the policies identified in the NECP, impacts were described by measures effectiveness and stage of development. With this methodology, it is possible to assess the impact of energy policies using indicators to characterize the effectiveness of the policy and the level of development. The study confirmed that both the multi-criteria analysis and composite index method can be used as methods. The results showed that high impact measures were related to the promotion of energy efficiency in buildings, but low impact measures were comprehensive horizontal measures such as measures related principle ‘energy efficiency first’ and review of energy efficiency obligation schemes. The indicators with the highest impact on sustainability rate were possible side effects and transparency of policies.

Description: Circular economy and industrial symbiosis represent a production and consumption model involving sharing, lending, reusing, and recycling existing materials and products in the most efficient way to increase sustainability and reduce or eliminate waste. Beef production has a high impact on the environment in different impact categories, especially those activities related to livestock breeding and feeding. In this study, a life cycle assessment and a life cycle cost evaluation are carried out investigating potential energy efficiency measures to promote industrial symbiosis scenarios referring to a proposed baseline scenario. Three main potential measures are evaluated: energy recovery from waste via anaerobic digestion, integration of renewable sources at warehouses, including solar PV panels, and the replacement of auxiliary equipment at the retailer. It was found that energy reconversion of food waste through anaerobic digestion and cogeneration provides the most valuable benefits to the supply chain. From the economic perspective, using a conventional life cycle cost assessment, the energy production from the use of wastes for anaerobic digestion proved to be the best potential option.

Description: Enhancement of anaerobic digestion is vital for substrate solubilization and increased biogas production at a reduced cost. The use of several iron-based additives has proven effective in improving overall bio-digester performance during anaerobic digestion sludge. This study evaluates different iron-based additives for the selection of the best additive from the alternatives using a multi-attribute decision making (MADM) approach. The weights of the attributes were computed with the entropy weight technique and the ranking of the alternatives were performed using order preference by similarity to ideal solution (TOPSIS) method. Five attributes and thirteen frequently used alternatives were selected for evaluation. The result showed that additive cost and dosages were assigned the highest weight of 62.37 % and 27.46 %, respectively. Based on the performance scores of 99.15 %, 20 mg/L of Fe3O4 nanoparticles (Fe3O4 NPs-20) ranked best (number 1) among considered alternatives for enhancement of anaerobic digestion of sludge. The outcome of this evaluation agrees with previous experimental results and suggests that the choice of an effective iron-based additive should be based on its biogas enhancement potential and cost-effectiveness (low dosage requirement and low price).

Description: Municipal solid waste (MSW) is an energy resource with sufficient energy/calorific value, making it a suitable substitute for fuel. This study investigated the effect of air flow rate on the MSW calorific value, the hemicellulose content, and the MSW degradation rate in a biodrying process. Four biodrying reactors equipped with flowrate and temperature recorders were used in the study. The air flow rate was varied as follows: 0 L/min/kg, 2 L/min/kg, 4 L/min/kg, and 6 L/min/kg, corresponding to reactors R1, R2, R3, and R4, respectively. The calorific value, water content, hemicellulose content, organic C content, and total N were measured on day 1, day 15, and day 30. The results showed that the biodrying process could increase the calorific value by 55.3 %, whereas the control reactor could increase the calorific value by only 4.7 %. The highest calorific value was 17.63 MJ/kg, at an air flow rate of 4 L/min/kg. The air flow rate had a significant effect on increasing the calorific value (sig.0.05). The biodrying process is the suitable method to increase the calorific value of MSW while reducing its water content; thus, the process promotes the realization of waste to energy as refuse-derived fuel.

Description: Within the framework of the study a case study is performed, the data provided by a Latvian textile production company on their electricity and natural gas consumption, as well as production volumes over a three-year period have been analysed. The specific indicators of electricity, natural gas and CO2 emissions have been calculated and the obtained results are shown in graphs. The correlation of specific indicators with production volumes was analysed by correlation coefficient and linear regression methods. An analysis of statistical data for the calculated specific indicators over a three-year period has been performed. The obtained results show high seasonality of natural gas consumption and close connection between electricity consumption and production volumes.

Description: Today cold chain transportation has become more important than before, as countries rely on cold chain logistics to store and transport SARS-CoV-2 vaccines and other temperature-sensitive goods. The cold chain is usually associated with the use of non-renewable materials and higher energy consumption than the regular supply chain. An important part of cold chain sustainability is thermal packaging. Up to now one of the most popular thermal packaging materials is polystyrene – made from fossil raw material. Polystyrene has low thermal conductivity and density, but it breaks down into micro- and nano plastics when exposed to sunlight making it environmentally unsustainable. To determine which factors are important for cold chain regarding thermal packaging, 12 criteria were compared to determine their ranking. Further multi-criteria analysis was used to compare polystyrene to four alternative biodegradable thermal packaging options: mycelium-based, corn starch, non-woven wool, and non-woven feathers. Polystyrene gained only 3rd place with a 0.70 proximity to ideal solution 1, but non-woven wool showed the best result with 0.88 proximity to ideal solution.

Description: The Baltic Sea is the youngest sea on our planet, the environment of the sea is considered to be unique and fragile. It is affected by various human activities resulting in the impairment of water quality. Riverine nutrient (nitrogen and phosphorus) loads are among the major causes of eutrophication of the Baltic Sea. This study examines temporal trends in water discharge, total phosphorus (TP) and orthophosphate-phosphorus (PO4-P) concentrations and losses from three agricultural runoff monitoring sites in Latvia including Berze, Mellupite, and Vienziemite. The annual datasets of TP and PO4-P concentrations and losses were tested for statistical trends using a nonparametric test - the Mann-Kendall trend test. The timeframe of this study was from 1995 until 2018. The results show a large variety of annual mean concentrations and losses of TP and PO4-P in the study period. No statistically significant trend was detected for TP losses. Meanwhile, statistically significant downward trends were observed for TP concentrations in four out of six study sites and in two study sites for PO4-P concentrations.

Description: The article focuses on the issue of the prospects of municipal organic wastes management in Ukraine in the context of the applicable EU practices in the field. The investigation was made according to the SWOT analysis. The general scientific and specific scientific methods were used at all the three stages of the investigation. The peculiarities of the Ukrainian legislation and their compliance with the EU directives and policies were analysed. The key problems of the Ukrainian wastes legislation, political and legal relations in the field were reviewed. The New Ukrainian Wastes Management Strategy was analysed. The main principles and priorities of the EU wastes strategies were presented. The best (and the most applicable for Ukraine) European practices were examined, including the five-step hierarchy and features of the national wastes collecting, sorting and disposal systems. Wastes composting technologies were discussed in detail. Possibilities of using wastes as bio fuel for refuelling municipal equipment, air transport, etc. were determined. The futility of expanding landfill areas for solving wastes management issues was noted. The main requirements to be met for regulating wastes management market in accordance with the Association Agreement with the EU were outlined. Recommendations on implementing circular economy principles and extended producers’ responsibility to encourage the public society to sort wastes, businesses to minimize wastes generation and draw interest to recycling were suggested.

Description: Energy retrofit of existing buildings is one of the main keys to achieve European Union’s decarbonising objectives defined in the European Green Deal. In order to proceed into them, European policy has been adapted and several research projects are developed. The aim of this paper is to analyse the assessment methodology of the research projects, setting up the overview of the assessed fields and the criteria followed to perform and evaluate each project. As working methodology, 18 projects have been studied, firstly characterising by the main parameters and afterwards analysing the assessment followed by each one. This analysis is decomposed into five parameters: the assessment scope, reflecting the fields covered by the project’s assessment; data source, the nature of the data; verification, use of data verification strategies; and implementation of life cycle thinking in the assessment methodology. The research shows that although the projects have their bases in the EU energetic targets they also cover a wider scope, assessing many fields and combining many sources of data. However, despite the large knowledge already defined by many projects, there is a lack of global and complete roadmap to be followed.

Description: Since 2008 many municipalities in the European Union have taken part in the Covenant of Mayors (CoM) initiative and have developed Sustainable Energy Action Plans (SEAP) to contribute to climate change mitigation. To respond to new policy goals for 2030, the CoM has expanded its focus and since 2018 requires municipalities to cover climate adaptation actions. The main aim of this paper is to analyse the first experiences of six municipalities from Spain, Portugal and Latvia in upgrading their existing Sustainable Energy Actions Plans to Sustainable Energy and Climate Action Plans (SECAP). SECAPs were developed through a participatory process involving all relevant local stakeholders, to gain maximum understanding and acceptance. Each municipality implemented climate adaption actions to demonstrate the need for adaptation and the ways it can be accomplished.

Description: Targets set by the European Green Deal to increase efficiency, reach towards sustainable development and to reduce greenhouse gas emissions have placed additional focus on necessary improvements in heating and cooling sector. This article aims to determine whether the objectives set at the EU and on the member state level for achieving climate and environmental goals are being implemented at the regional and local levels. The case of Latvia is considered. A keyword extraction text analysis method is used to identify whether improving the efficiency of heating and cooling is included in regional and local sustainable development strategies. Results are evaluated by using multi-criteria analysis methods TOPSIS and AHP, to determine how much attention in the strategies is paid to direct heating and cooling supply aspects and overall efficiency aspects. Results obtained while assessing the sustainable development strategies of cities and municipalities are compared with the climate index of their heating supply. Considerable differences can be seen in the inclusion of heating and cooling efficiency improvement plans in the strategies at regional and local levels.

Description: The aim of the article is to determine what amount of hydrogen in %mol can be transferred/stored in the Estonian, Latvian and Lithuanian grid gas networks, based on the limitations of chemical and physical requirements, technical requirements of the gas network, and quality requirements. The main characteristics for the analysis of mixtures of hydrogen and natural gas are the Wobbe Index, relative density, methane number, and calorific value. The calculation of the effects of hydrogen blending on the above main characteristics of a real grid gas is based on the principles described in ISO 6976:2016 and the distribution of the grid gas mole fraction components from the grid gas quality reports. The Wärtsila methane number calculator was used to illustrate the effects of hydrogen blending on the methane number of the grid gas. The calculation results show that the maximum hydrogen content in the grid gas (hydrogen and natural gas mix), depending on the grid gas quality parameters (methane number, gross heat of combustion, specific gravity, and the Wobbe Index), is in the range of 5–23 %mol H2. The minimum hydrogen content (5 %mol H2) is limited by specific gravity (〉0.55). The next limitation is at 12 %mol H2 and is related to the gross heat of combustion (〉9.69 kWh/m3). It is advisable to explore the readiness of gas grids and consumers in Estonia, Latvia and Lithuania before switching to higher hydrogen blend levels. If the applicability and safety of hydrogen blends above 5 %mol is approved, then it is necessary to analyse the possible reduction of the minimum requirements for the quality of the grid gas and evaluate the associated risks (primarily related to specific gravity).

Description: Indian cities are highly dependent on road transport for freight and passenger traffic movements. The estimated road transport led yearly emission inventory of pollutants for 25 million-plus population cities of India indicates vehicle stock as the critical contributor to air pollution in cities. During 2025 the city of Kolkata will be responsible for the emission of 21 668.24 Gg of CO2 followed by 272.81 Gg of CO, 98.21 Gg of NOX, 16.9 Gg of CH4, 93.39 Gg of SO2, 8.6 Gg of PM, and 38.55 Gg of HC due to its 2.79 million vehicles. The total vehicle stock of 25 leading Indian cities increased by 19 % during 2015–2017, and during the same period, Rajkot and Vadodara had the highest rise of 97 % and 94 % respectively. Out of 25 cities total CO2 (220 560 Gg) and CO (3185 Gg) vehicular emissions during 2017, Delhi was the highest contributor with 22 % and 20 % respectively followed by Bengaluru (12 %, 12 %), and Chennai (9 %, 8 %). The GHG emission per unit area of Kolkata during 2017, due to on-road vehicular emission, was the highest amongst the 25 cities of India. For Kolkata, cars were responsible for 35 % for CO2, 55 % of CO, 75 % of CH4, 27 % of PM, omnibuses for 41 % for NOX emission, taxis for 83 % of SO2, and two-wheelers for 36 % of HC emissions.

Description: The Earth’s inner core comprises iron-nickel alloys with light elements. However, there is no clarity on the phase properties of these alloys. Here we show phase relations and equations of state of iron–nickel and iron–nickel–silicon alloys up to 186 gigapascals and 3090 kelvin. An ordered derivative of the body-centred cubic structure (B2) phase was observed in these alloys. Results show that nickel and silicon influence the stability field associated with the two-phase mixture of B2 and hexagonal close-packed phases under core conditions. The two-phase mixture can give the inner core density of the preliminary reference Earth model. The compressional wave velocity of the two-phase mixture under inner core conditions is consistent with that of the preliminary reference Earth model. Therefore, a mixture of B2 and hexagonal close-packed phases may exist in the inner core and accounts for the seismological properties of the inner core such as density and velocity deficits.

Description: The aim of the study was to determine air pollution over the sea surface (North Sea and Baltic Sea) comparing to concentration in the closest land areas to examine the impact of ships on the level of PM concentration. The analysis is based on the measurements made during the two weeks cruise of the tall ship Fryderyk Chopin from Edinburg to Kołobrzeg. The highest pollution levels were observed in locations distant from the coast, especially over Baltic Sea, with increasing concentrations when other ships approaching. The article attempts to assess the possibility of migration of pollutants to these areas from land-based sources, and thus indicate the degree of their participation in the level of pollution present at sea.

Description: This paper focuses on the thermal characteristic of the torrefied pinecone pellets. The resistivity heating system was used for torrefaction purposes. The torrefaction was conducted at 523 K for different holding times of 5, 10 and 15 minutes. The thermal behaviour of the pinecone pellet was numerically predicted using the pdepe algorithm. A parabolic 2-D heat transfer equation was used to estimate the thermal profile across the pinecone. The effect of the interactive atmosphere was on the numerical solution was also examined. The pelletisation was performed using a ring-die at the temperature of 70 °C.

Description: Single family houses consume substantially more thermal energy per floor area compared to multi-apartment buildings to satisfy space heating or cooling demand. Over the past decades there has been an undisputed evidence of a temperature rise across the world that has led to a growing concern of more extreme weather patterns and regular seasonal heat waves globally. As such, building occupants are at a continuously growing risk to overheating exposure inside the premises. Within the framework of this study a single-family house was examined with respect to its thermal performance in warm and cold seasons. A simulation model was developed in IDA-ICE software to evaluate annual thermal energy demand for a reference scenario, 3 shading scenarios and for an optimized scenario. At an optimized scenario that incorporates mechanical ventilation with a heat recovery unit and enhanced thermal performance of the external building elements, the annual thermal energy demand in the proposed single-family house was reduced by 39.5 % compared to the reference scenario, which is a significant step towards meeting nearly zero energy building criteria.

Description: Advances in technology over the past few years have allowed us to evolve from waste to value. Food waste has been an increased recognition that more attention needs to be paid to this area. With this concern, research on fruit waste valorization into medicinal products has a rich background. This paper approaches the problem with a broader perspective by introducing the fruit waste valorization pathway. The key idea in this paper is to use the multi-criteria analysis method to choose the best essential oil extraction technique from fruit waste. The performance of four different extraction methods i.e., steam distillation, cold-pressing, solvent extraction, and hydro distillation compared in the approach, considering the environmental, economic, social, and technical criteria. The methodology was developed with two scenarios, by using the Analytic hierarchy process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methods. Our research highlighted that cold-pressing extraction is the most effective technique for essential oil extraction in both scenarios.

Description: Constructed wetlands as a treatment system are widely explored in different climate conditions and established to be effective in pollution removal from water environment. This study aims to demonstrate the performance of pilot-scale subsurface flow constructed wetland for storm water treatment in Latvia. The catchment basin was located in a farmyard of agricultural area and storm water was collected from the impermeable pavements. Storm water was accumulated in an open pond and periodically pumped above the filter part of the subsurface flow constructed wetland. Grab samples were collected once or twice per month at the inlet and outlet of the treatment system during a period of 73 months from year 2014 to 2020. Water quality parameters as nitrate nitrogen (NO3-N), ammonium nitrogen (NH4–N), total nitrogen (TN), orthophosphate phosphorus (PO4-P), and total phosphorus (TP), total suspended solids (TSS), biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) were monitored. Water level at the inlet structure was automatically measured and flow rate was calculated based on the Manning equation for partially filled circular pipes. Results showed the reduction of average concentrations for all parameters during the study period. However, in some sampling cases concentrations increased at the outlet of the treatment system and can be explained by influencing factors of farming and maintenance. The treatment efficiency of NO3-N, NH4-N, TN, PO4-P, TP, TSS, BOD5 and COD concentrations was 17 %, 68 %, 55 %, 78 %, 80 %, 57 %, 80 % and 74 %, respectively. The study site demonstrated a potential to improve water quality in the long term.

Description: Biodiesel is an environmentally friendly fuel, produced by a transesterification process using homogeneous catalyst which causes water pollution and cannot be recycled. The present study utilizes industrial brine sludge waste (IBSW) as a heterogeneous catalyst in the transesterification of waste cooking oil (WCO) into biodiesel. One variable at a time design was applied to optimize the transesterification process. The process variables were varied as follows: methanol to oil weight ratio (10–50 %), reaction time (0.5–2.5 h), reaction temperature (30–90 °C) and catalyst to oil weight ratio (0.84–4.2 %). The IBSW before and after calcination and the transesterification process was characterized using X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy and scanning electron microscope (SEM). Biodiesel was produced at maximum yield of 95.51 wt% at reaction time, temperature methanol to oil weight ratio, and catalyst to oil weight ratio of 1 hour, 60 °C, 30 wt%, and 2.52 wt% respectively. The FTIR and SEM results confirms that before and after the transesterification process the modification of IBSW took place. Using the ideal process conditions, biodiesel was produced and vital fuel properties such as viscosity, density, pour point and flash point were measured and were found to be within the specification as per American Society for Testing and Material (ASTM) standards for biodiesel. The reusability of the IBSW catalyst was tested by recycling and it can be established that the catalyst can be utilized up to four times without affecting its catalytic activity.

Description: Lake ecosystems are important elements of hydrological regime, the quality of these ecosystems is affected by anthropogenic actions, and therefore, a variety of organisms, living in these habitats depend on the applied management solutions. Due to human activities freshwater ecosystems suffer from loss of biodiversity and increased eutrophication. Therefore, important aspects related to lake management include knowledge about the water quality, ecosystem response to climate change as well as increased risks of appearance and spreading of invasive species. Water quality, content of oxygen, nutrients, phytoplankton and distribution of macrophytes, including invasive species were analysed in Balvu and Pērkonu lakes. Presence of invasive species Canadian waterweed (Elodea canadensis) was detected, however, common reed (Phragmites australis) can be considered as expansive species. The analysis of current situation and existing management measures indicates persistent spreading of those species. Significant changes of lake water quality and climate may increase possible spreading of other, more aggressive, invasive species, for example – Nuttall’s waterweed (Elodea nuttallii).

Description: District heating has proven to be an efficient way of providing space heating and domestic hot water in populated areas. It has also proven to be an excellent way to integrate various renewable energy sources (RES) into the energy system. In Estonia, biomass covers most of the heat demand, but carbon-intensive fuels are still used to cover peaks and lows. Heat pumps can be a good solution for rural areas, as there is usually plenty of land available for heat pump facilities. In addition, heat pumps require low-grade heat sources such as ambient air, groundwater, lakes, rivers, sea, sewage water, and industrial waste heat. One of the downsides of heat pumps is the need for large investments compared to boilers fired by natural gas and biomass, and electric boilers. This study examines the impact of heat pump use on consumer prices for district heating in rural district heating networks in Estonia.

Description: The article outlines the main problems that the cement industry causes to the environment. Authors propose technological solutions aimed at resource-saving in cement production and environmental protection. The research is devoted to low-energy cement obtained on the basis of waste from processing skarn-magnetite ores. The characteristics of the composition and properties of the technogenic material are given. The authors have justified the feasibility of using skarn-magnetite ore enrichment waste as a part of a cement raw material mixture. The possibility of changing the composition of cement by reducing the energy-intensive alite phase is demonstrated. Technological and heat engineering calculations confirming the reduction of natural mineral raw materials and fuel costs in the production of cement were carried out. The processes of hydration of the developed cements have been investigated. A method for accelerating the hardening of low-base cements due to mechanical activation, the introduction of mineral additives and a modifier is proposed. The research revealed construction and technological advantages of the developed cements, which exhibit increased resistance during operation in an aggressive environment. Physical and mechanical tests of concretes made of low-base cement were carried out. The possibility of reducing the temperature during the heat treatment of concrete is proved. Physical and mechanical tests of concretes made of low-base cement were carried out. The paper presents environmental benefits of the developed cement technology.

Description: The study presents the experimental and analytical investigation, which was carried out to evaluate the charging/discharging performance of phase change material (PCM) in the thermal energy storage (TES) unit. The experiments performed under different operating modes of the heat storage system, changing the inlet temperature and the mass flow rate of the heat transfer fluid (HTF). The calculated amount of thermal energy based on the partial enthalpy distribution provided by the manufacturer’s datasheet compared to that obtained from the experiments. Based on the experimental results, a three-dimensional response surfaces formed and a regression models obtained, which allow predicting the PCM charging and discharging performance.

Description: Carbon dioxide emissions are strongly related to climate change and increase of global temperature. Whilst a complete change in producing materials and energy and in traffic and transportation systems is already in progress and circular economy concepts are on working, Carbon Capture and Storage (CCS) and Carbon Capture and Utilisation (CCU) represent technically practicable operative strategies. Both technologies have main challenges related to high costs, so that further advanced research is required to obtain feasible options. In this article, the focus is mainly on CCU using microalgae that are able to use CO2 as building block for value-added products such as biofuels, EPS (Extracellular Polymeric Substances), biomaterials and electricity. The results of three strains (UTEX 90, CC 2656, and CC 1010) of the microalgal organism Chlamydomonas reinhardtii are discussed. The results about ideal culture conditions suggest incubation temperature of 30 °C, pH between 6.5 and 7.0, concentrations of acetate between 1.6 and 2.3 g L–1 and of ammonium chloride between 0.1 and 0.5 g L–1, the addition of glucose This green microalga is a valid model system to optimize the production of biomass, carbohydrates and lipids.

Description: Six-year records of ocean bottom water temperatures at two locations in an isolated, sedimented deep-water (∼4500 m) basin on the western flank of the mid-Atlantic Ridge reveal long periods (months to 〉1 year) of slow temperature rises punctuated by more rapid (∼1 month) cooling events. The temperature rises are consistent with a combination of gradual heating by the geothermal flux through the basin and by diapycnal mixing, while the sharper cooling events indicate displacement of heated bottom waters by incursions of cold, dense bottom water over the deepest part of the sill bounding the basin. Profiles of bottom water temperature, salinity, and oxygen content collected just before and after a cooling event show a distinct change in the water mass suggestive of an incursion of diluted Antarctic Bottom Water from the west. Our results reveal details of a mechanism for the transfer of geothermal heat and bottom water renewal that may be common on mid-ocean ridge flanks.

Description: In 2018, 4.1 billion tonnes of freight and 437 million passengers passed through the 1200 European ports. This dimension of geographically concentrated activities is the rationale that ports are characterised by a high-energy demand and a high share of emissions. Driven by a growing awareness for a cleaner environment, a stronger focus on sustainability and intensified environmental regulations, ports are forced to take responsibility when it comes to environmental issues. As a response, in recent studies, the concept of ‘green ports’ emerged. Simultaneously, in the context of digitalisation, the term ‘smart ports’ has received growing attention in the latest scientific discussions, too. Since an important driver towards greener maritime operations is linked to digitalisation, we argue that digital efforts in ports should next to the automation of inherent logistics processes also contribute to reducing the emissions and energy demands. Previous studies have primarily concentrated on the automation of container handling operations. Hence, there exists a research gap concerning the automation of bulk cargo handling operations in ports. Thus, this study addresses the question of how to automate the dry bulk cargo loading operations in the frame of a green and smart port development. The developed case study refers to the seaport of Wismar, whereby the results show that the digitalisation and greener port operations can be successfully aligned. Overall, this study extends the discussion on green and smart port development, while it contributes to the scientific literature by proving that both conceptual ideas can be achieved in the operating business.

Description: To address the biomass waste processing problem and transform it into refractory forms of carbon, recently suggested hydrothermal carbonization (HTC) of biomass in alkaline environment can be considered as a prospective and climate neutral approach. Biomass HTC provides possibilities to obtain form of biochar (hydrochar) and artificial humic substances, however the conditions of the HTC have not been much studied. Optimization by Response Surface Methodology of the HTC using microwave treatment with three experimental variables (treatment temperature, length of microwave treatment, amount of biomass per volume) provides the possibility to significantly increase the yield of humic substances at the same time reducing the duration of the treatment. However, with an increase in the yield of humic substances, the yield of hydrochar decreases, thus supporting possibilities to obtain most needed biomass waste processing product.

Description: Implementing provisions of the EPBD all Member States require to provide EPC (Energy Performance Certificate) when buildings are c onstructed, sold or rented. The purpose of the certificate is to compare buildings’ performance and inform the end-users. However, quite many mismatches and discrepancies could be found when comparing actual energy consumption with the once declared by the EPC. This mismatch of energy demand is known as Energy Performance Gap (EPG). It was analysed by different researchers on national levels. In the study, an overall overview of the high-performance buildings in Lithuania is performed and EPG is analysed using statistical indicators. Analysis has shown that for class A the EPG varies from −101 % to +77 %. More buildings are found to have a positive Energy Performance Gap. For class A+ and A++ variations are within a narrower interval: from +18 to 76 % and from +23 to 77 % accordingly. It confirms the findings in the other countries that very high-energy performance buildings tend to consume more than predicted. Also it is confirmed that despite differences in national certification methodologies, the same problem (just of different scale) exists and EPC schemes need revisions.

Description: This paper aims to provide an evaluation of solar energy efficiency by composite index and to compare the value of solar energy across 19 countries located over four continents: Europe, Africa, America, and Asia. 15 indicators were evaluated for the year of 2019 and grouped into four dimensions: economic, social, technical, and environmental. Analytical Hierarchy Process (AHP) was used to estimate the weight of each indicator, and consistency tests were calculated to evaluate weight efficiency. The obtained results of the SEI reveals that the technical dimension and economic dimension play an important role in the solar energy efficiency of a country. The results indicate potential improvement areas for increasing solar efficiency. SEI can be used as a tool in assessing solar energy potential integration in a country.

Description: The current rural dwelling pattern in the Delta in Egypt consumes much energy to achieve dwellers’ thermal comfort, increasing greenhouse gas emissions contributing to climate change threatening the region’s coastal parts. Therefore, this study highlights the potential of retrofitting the existing rural house utilizing pervasive construction technologies in diminishing energy consumption and carbon dioxide emissions as a climate change mitigation strategy. The current modern rural house and the construction typologies were characterized. This study selected a typical modern rural dwelling located in Al-Gharbia Governorate in the Delta region. The suggested retrofitting strategies were applied to the external building envelope. The impact on the annual energy consumption of cooling and heating loads was evaluated using an Energy Performance Assessment Tool (Design Builder). An optimal envelope configuration was suggested, then an economic assessment and an investigation to the local acceptance were provided. The results showed that using the commonly used construction techniques as a retrofitting strategy can plummet the energy consumption and CO2 emissions by one-third worthy of mentioning that the locals have shown a lack of interest in the investment in retrofitting their buildings as well as the economic model showed that the investment is not profitable. Further studies can be made by the author considering investigating different building typologies and engaging other stakeholders.

Description: It is expected that Cross-laminated timber (CLT) and other engineered wood products will experience rapid growth in the coming years. Global population growth is requiring more housing units, at the same time the negative impact of construction industry cannot stay in the same level as today. Alternatives for concrete and steel reinforced structures are being explored. CLT has proven to be an excellent substitution for concrete regarding construction of buildings up to eight storeys high. In addition to much lower environmental impact, construction process using CLT takes significantly less time due to pre-cut shapes required for specific project. Despite mentioned benefits, there are considerable amount of CLT cuttings generated in this process. Due to irregular shape and small dimensions of these cuttings they are useless for further use in construction. By applying re-processing technology described in this paper, around 70 % of generated cuttings can be re-processed into new CLT panels. In this paper we are evaluating the environmental benefits of re-processing these cuttings into new CLT panels versus business-as-usual scenario with waste disposal. Life cycle assessment results showed significant reduction of environmental impact for the scenario of CLT cutting re-processing.

Description: This article presents an evaluation of the performance of PV modules with the variation of some technical and environmental parameters: The PV module tilt angle, and the impact of soiling on the power output of PV module, and the transmittance of the PV glass surfaces. The experiments were achieved in Helwan City (Egypt) at the premises of the Faculty of Engineering of Helwan University. For the soiling part, it comprises two experiments: Transmittance of PV glass surfaces, and the power output of PV modules. For the transmittance experiment, it has been achieved using a simplified method, where three PV glass surfaces were placed at three different tilt angles (0°, 15°, and 30°) and left exposed to the outdoor environment without cleaning for a period of 25 days during the summer season. For the experiment concerning the impact of soiling on the power output, a set of PV modules connected in series have been exposed for a period of 75 days to the outdoor environment without cleaning. Finally, for the PV module tilt angle experiment, another set of PV modules have been used for that purpose, where four different tilt angles were experimented: 0°, 15°, 30°, and 45°. The present research recommends that more studies are needed in the same context, taking into consideration correlating the technical and environmental parameters in one single experiment and during different times of the year. This would be helpful in having overarching perspective regarding the electrical performance of PV modules under different circumstances of tilt angles and soiling patterns within the area of Helwan (Egypt).

Description: Inadequate municipal waste management, associated with a dominance of waste landfilling and low efficiency of resource and energy recovery, is the major challenge towards circular economy targets for some European Union countries, including Latvia. The aim of the study is to evaluate environmental performance from implementation of waste management policy goals in waste management systems of Latvia applying life cycle assessment methodology. The waste management system in Latvia was evaluated for two scenarios: baseline situation (based on statistical data from 2016) and future scenario – 2030. Baseline scenario assessment results show the existing material and energy recovery potential from municipal solid waste generated in Latvia. Meanwhile, results obtained from the 2030 scenario demonstrated that boosting recovery rates of plastic by 20 % and organic waste by 20 % can contribute to the minimization of life cycle environmental impacts (human health, resources, climate change, ecosystems) by 1.8 % and organic by 3.6 % correspondingly.

Description: The European Union (EU) has set ambitious targets to increase the overall energy efficiency and decrease the environmental impact by introducing the ‘Green Deal.’ It is an EU plan for the transition to zero greenhouse gas emissions. The overall data analyses of GHG emissions per capita and GDP value in different EU countries show that the GDP increase in 2010–2017 has not increased GHG emissions. Therefore, the link between the GDP increase through energy resource usage increase has been eliminated. However, not all of the EU 27 member states contributed to the overall EU green policy equally. The article presents the methodology for the energy and environmental performance status analyses by evaluating nine different indicators (share of renewable energy, greenhouse gases per GDP, energy intensity, primary efficiency, industry efficiency, energy consumption in households, space heating efficiency, pollutant emissions from transport and specific energy consumption of transport sector) for EU member states. Indicators have been tested through correlation analyses. The use of multidimensional Energy and climate policy indicator has been proposed to rank the performance of different EU countries. The results show that the countries with the highest score in climate and energy indicator values are Sweden, Denmark, Latvia, Austria, Finland, Ireland, and Lithuania. The lowest obtained values are Bulgaria, Poland, Hungary, the Czech Republic, and France.

Description: The manufacturing industry in Europe is currently enfacing one of its greatest challenges due to the emission reductions needed to reach carbon neutrality by the middle of this century. The European Union’s Energy Efficiency Directive and Green Deal will force manufacturing industries to significantly reduce their present energy consumption, but at the same time sustain their competitiveness globally. Here we use the Latvian manufacturing industry as a case to analyse how different macro-level factors have affected its energy use and how the industrial energy efficiency has progressed during the last decade. We apply the Log-Mean Divisia index decomposition method to decompose the energy use in the manufacturing subsectors over the period of the past ten years from 2010 to 2019. The findings unravel the key driving factors of industrial energy consumption, which could serve as a valuable basis for effective energy efficiency policymaking in the future. The results show that energy consumption trends differed across industrial subsectors and the effect of industrial energy efficiency improvements was more pronounced in the period following the entry into force of Energy Efficiency Law in Latvia. Significant increases in energy consumption are observed in the two largest Latvian manufacturing subsectors, such as the non-metallic minerals production sector and the wood processing sector, where the current pace of energy efficiency improvements cannot compensate for the effect of increasing industrial activity, which increases overall industrial energy consumption. The results suggest that the Latvian manufacturing industry is at the crossroads of the sustainability dilemma between economic gains and energy saving targets.

Description: The industrial development of mankind is based on the intensive use of natural resources of the planet. The development of the mining industry is a necessary and important factor for the successful development of the national economy. At the same time, mining has a significant impact on environmental degradation. Methods for assessing and minimizing the environmental impact of mining have only been developed in practice in the last 50 years and differ significantly from country to country. The article analyses the approaches and methodologies for environmental impact assessment (EIA) based on international and national standards. The methods used in Kazakhstan and the countries of the European-Asian Economic Union (EurAsEU) are critically evaluated. The developed mathematical models are implemented in the form of digital solutions and implemented in the module of the cloud system ‘3D Quarry’. The methodology proposed by the authors for use and the developed software product allow optimizing mining operations at quarries according to the parameters of minimizing their negative impact on the environment. At the same time, it is mandatory to comply with mandatory national and international regulations. The proposed 3D Quarry system and the EIA module are an alternative to commercial software products (and their pirated copies, often used by companies in the countries under study) and are aimed at small mining companies in post-Soviet countries. It is expected that the application of the proposed software product will allow, within the technological capabilities, to minimize the impact of quarries on the environment of Kazakhstan.

Description: Significant oil losses in oil-containing wastes and their adverse impact on the region environmental setting bring about the need to develop an oil-containing wastes treatment technology. To tackle this issue, the authors have set an aim of designing a helio device and creating an oil-containing wastes treatment method based on it to extract oil products. Considering a widespread in the composition and properties of potential oil sludge raw materials and their tendency for either formation of stable emulsions or phase separation, we have conducted in-depth modern physical and chemical studies and defined the need to develop a commercial oil-containing wastes purification method. We have designed the device, in which oil product hydrocarbons undergo thermal treatment using solar energy. Following oil-containing wastes purification using solar energy, the particulate load in soil does not exceed 6.65–6.79 % and the absolute molecular weight of hydrocarbons approaches that of bitumen. The developed oil-containing wastes purification method solves an important environmental issue of oil-containing wastes recycling, promotes recovery, and prevents degradation of natural complexes, and reduces soil and water pollution.

Description: A number of intergovernmental agreements, the most important of which are the Paris Agreement (UN Framework Convention on Climate Change) and the European Green Deal, provide for resource efficiency and the reduction of greenhouse gas and particulate matter (PM2.5, PM10) emissions to 2030 (short-term program to reduce emissions by at least 55 %) and to achieve emissions-neutral production, transport and household activities by 2050. The European Union (EU) has taken the lead in developing and implementing climate change mitigation policies for both industrial and private residential homes in the world through a green course. As an EU country, Latvia has joined both the EU-level climate policy and developed its policy, regulatory documents and action plans for 2021–2030 (Latvia’s National Energy and Climate Plan for 2021–2030), climate policy, including a policy aimed at significantly reducing GHG emissions and increasing efficiency in the household sector. Achieving these climate policy goals requires both a change in human habits and more efficient technologies. This article discusses one of the technological solutions that can reduce both greenhouse gas emissions and the release of PM2.5 and PM10 from individual heating systems in private homes and small commercial facilities. Calculations of electrical energy production in mCHP mode of the system for household self-consumption based on experiments will be done. The technology involves the production of heat from biomass or other types of renewable energy sources while generating electricity for self-consumption. Conclusions of CHP mode on overall efficiency will be done.

Description: Mitigation of CO2 emissions has become a top-question in international and national arenas, likewise on the city level. Existing CO2 mitigation measures are primarily oriented towards wider deployment of low-carbon technologies of renewable energy sources and energy efficiency measures, focusing on energy production, distribution and energy use sectors, as well as the transport sector. Due to higher CO2 reduction efficiency and the cost aspect, the direct CO2 mitigation options currently applied are mostly oriented on large scale CO2 generators. Meanwhile the rural, sparsely populated regions already suffer from a lack of innovative industrial economic activities, inhabitant’s migration to urban areas and mostly involved in agriculture, land use and forestry activities. They are also “saved” by the public authorities from targeted CO2 emissions mitigation actions, therefore, the understanding of processes within rural CO2 economy sectors, factors, interconnections and effects to the environment and nature quality and finally guidelines to future actions are crucial. To analyse CO2 valorisation options for regional development, a multi-modelling approach combining literature review, an indicator analysis method and a multi-criteria decision-making analysis were used. As a result, CO2 valorisation options and key performance indicators were defined and multi-criteria analysis for regional decarbonization scenarios were performed.

Description: Digitalization projects are actively underway in the energy industry, such as the power industry and oil and gas industry. However, there has been no in-depth and quantitative analysis of the relationships between the participants, industry, and technology of digital projects. Therefore, this study focused on which technologies are invested according to key characteristics such as the types of participants and industries driving digitalization projects. This study also examined whether there are differences in technology choices depending on the degree of clean energy exposure. Based on statistics from Bloomberg New Energy Finance (BNEF), a total of 711 projects were analysed using multinomial logistic regression (MNLR). As a result, the proportion of Analytics software was generally higher in the whole industry, and the energy industry was more likely to invest in Analytics software than in other industries. Comparing the power, oil and gas sectors, there was a high probability of investment in Internet of Things (IoT) in the power sector and Automation in the oil and gas sector. In the type of cooperation between energy companies and industrial companies, the probability of investing in Analytics software was significantly higher. In the case of cooperation between energy companies and information and communications technology (ICT) companies, in the oil and gas sector, Analytics software and Cloud/Data accounted for a large proportion. This study provides insight into the effect of characteristics of energy digitalization projects on the technology choice.

Description: Latvia, like many other European Member States, faces major challenges in achieving climate goals within the Paris Agreement – emission reduction for 50–55 % by 2030 and net-zero emission economy by 2050. Decarbonization of the energy sector is one of the main aims and sustainable use of biogas is one of the ways to reach these targets. Although the biogas sector in Latvia is now mainly based on the production of electricity and heat in cogeneration plants, often using specially grown energy crops, and payments of the mandatory procurement component have expired, biogas plants are preparing for reconstruction for the production of biomethane with the help of European fund investments. It means that the biogas sector is moving towards a completely different operating model, based primarily on the management of agricultural waste as a feedstock, the conversion of biogas to biomethane and it is used mainly in the transport sector, but its implementation in practical terms faces various challenges. In this context, this article offers a clear vision of the development of the biogas sector in the next decade in Latvia. It uses a sustainability SWOT analysis to clearly reflect the sector’s strengths, weaknesses, opportunities and threats.

Description: Just over half of the energy consumed in Jordan is consumed by transportation, of which passenger cars account for 57 %. This has increased fuel bills and elevated CO2 emissions, creating social and economic pressures. However, these can be ameliorated by enhancing the efficiency with which energy in the transportation sector is utilised. In Jordan, most of the passenger cars in 2017 ran on diesel and gasoline fuel, with only a small percentage (0.23 %, equivalent to 3586 cars) running on electricity. The aim of this paper was to assess the possible advantages of replacing passenger cars that run on fossil fuel with electrically powered vehicles. This was achieved through an examination of six scenarios where the key variable was the type of fuel needed to produce the electricity required to charge the cars. Different replacement percentages were also tested. Detailed analysis and calculations of CO2e emissions and the electricity needed were then performed. The results indicated that replacing fossil fuel passenger cars with electric cars is an effective option for reducing the amount of CO2e emissions and can decelerate the rate at which energy is consumed in the transportation sector, dramatically reducing the national fuel bill. If the running costs of car fuel are reduced, the use of renewable energy technologies based on solar and wind will also reduce the level of GHG emissions.

Description: The study aims to substantiate theoretical and methodological aspects of the use of strategic environmental assessment as an instrument for public regulation of the ecological status of territories. The research methodology is based on using a systematic approach for conducting a strategic environmental assessment of the possibility of environmental problems and threats posed by the implementation of long-term projects and current activities. The development of ecological balance, comparison of the results of normative and exploratory forecasts of the state of the environment become the basis for the formation of goals of strategic environmental management, the appearance of a set of measures for the conservation and restoration of natural resources. Identification of factors influencing the state of the environment is a necessary condition for the prevention of pollution of territories, inefficient use of natural resources, justification of the essential measures of state regulation to ensure the achievement of goals. The practical experience of assessing the achievements in the management of the conditions of the environment is illustrated by the example of regions of Ukraine. The proposed approach to the development of the ecological balance and the methodology of complex assessment of the ecological status of the territory have scientific novelty and contribute to the assessment of the effectiveness of public administration balanced development of the territories.

Description: Positive Energy District (PED) is a relatively new concept from which many projects are planned, however, only a few cases are currently close to be materialized, therefore, in this study the PED projects in operation and in implementation process in existing districts are gathered in order to serve as a base for future PEDs. In this sense, certain points of each selected project are highlighted due to their relevance within the project development and their replicability potential. Furthermore, intending to learn from the experience of the assessed case-studies, this paper aims to understand the current situation regarding PED implementation to simplify the development of further PEDs.

Description: The industry sector in many countries has a significant role in reaching national long-term emission reductions, energy efficiency and renewable energy targets. New technologies, wide implementation of energy efficiency measures and smart energy management are needed for the industry to ensure local and global competitiveness and reduce emissions. Since the industrial sector is often comprised of sub-sectors that are unique and with local specifics, this paper focuses on three of them, taking Latvia as the case. The sectors are: manufacture of wood and wood products, non-metallic mineral products, as well as food products and tobacco. These sub-sectors together consume around 80 % of the total final energy use in the country’s industrial sector. Comprehensive analysis and decomposition of the sub-sectors was made to identify future development pathways. TIMES model was used to elaborate a process-oriented modelling approach to analyze the impact of measures defined in the National Energy and Climate Plan until 2030 as well to gauge the impact of additional measures. Results show that these measures promote the use of renewable energy and improve energy efficiency, however it is necessary to set new measures and activities for the period beyond to reach climate neutrality by 2050.

Description: Methyl ester biodiesel was produced from Moringa Oleifera oil and Jatropha Curcas oil with the sole aim of assessing the feasibility of the feedstocks as viable sources of biodiesel in Botswana. Oil extraction and transesterification were carried out under identical experimental conditions for both Jatropha Curcas and Moringa Oleifera biomass. Oil was extracted from seeds through a soxhlet extraction method using the solvent, n-hexane. The extracted oil was then trans-esterified at 60 °C using a methanol/oil ratio of 12:1 at a stirring rate of 350 rpm, 3 wt. % catalyst loading and 120 min reaction time. Zinc Oxide modified with fly ash was used as heterogeneous catalyst for the process. GC analysis results of biodiesels produced indicated that the highest biodiesel yield was obtained from Jatropha seed oil. Moringa biodiesel showed a greater proportion of docosanedioic acid while Jatropha biodiesel composed of oleic acid in larger proportions. Both oleic and docosanedioic acid are unsaturated methyl esters. The results obtained suggests Jatropha as the more suitable feedstock as compared to Moringa.

Description: Substituting Hydrofluorocarbons with natural refrigerants in domestic refrigerators will significantly reduce the direct contributions of fluorinated gases to global warming which will be of great environmental benefit. In this study, the performances of dimethyl-ether (RE170) and its azeotropic mixtures (R510A and R511A) in a refrigeration system were assessed theoretically and compare with that of conventional refrigerant. The study revealed that the three investigated alternative refrigerants exhibited significantly good heat transfer characteristics, low pressure ratio, high latent heat in the liquid phase which resulted in their high thermal conductivity and Volumetric Cooling Capacity (VCC). The thermal conductivity of the refrigerants reduces while the evaporating temperature rises and the value obtained for RE170 was the highest among the four refrigerants studied. The Coefficient of Performance (COP) for RE170, R510A and R511A were higher than that of R134a by 6.20, 10.06 and 3.02 % respectively while their power consumptions per ton of refrigeration were lower than that of R134a by 6.99, 11.04 and 1.47 % respectively. In conclusion, dimethyl-ether and its azeotropic mixtures performed better than R134a in that they have higher thermal conductivity, refrigerating effect, VCC, COP, lower power consumption per ton of refrigeration and hence, they can be considered as suitable replacements for R134a in domestic refrigerator.

Description: This study presents the environmental impact of apparel consumption in Australia using life cycle assessment methodology according to ISO14040/14044:2006. Available published references, the Ecoinvent v3 dataset, the Australian life cycle assessment dataset and apparel country-wise import data with the breakdown of apparel type and fibre type were used in this study. The environmental impact assessment results of the functional unit were scaled up to the total apparel consumption. The impact results were also normalized on a per-capita/year basis. The Total Climate Change Potential (CCP) impact from apparel consumption of 2015 was estimated to be 16 607 028 tonnes CO2eq and 698.07 kg CO2eq/per capita-year. This study also assessed the impact of acidification potential (AP), water depletion (WD), abiotic resource depletion potential (ADP) - fossil fuel and agricultural land occupation (ALO) using the same methodology. The market volume of cotton apparel in Australia is 53.97 %, which accounts for 45 %, 96 %, 40 %, 46 % and 79 % of total CCP, WD, ADP, AP and ALO impact, respectively. Apparel broad categories of cotton shirt, cotton trouser, polyester shirt and polyester trouser have a high volume in the apparel market as well as a high environmental impact contribution. These high-volume apparel products can be included in the prioritization list to reduce environmental impact throughout the apparel supply chain. It was estimated that from 2010 to 2018 the per capita apparel consumption and corresponding impact increased by 24 %.

Description: Green growth and sustainable development goals (SDGs) are two strategies to improve the productivity and competitiveness of countries with respect to environmental protection. In these strategies, science, technology and innovation (STI) plays an important role in generating new knowledge. Colombia is a highly diversified country that is currently seeking to promote green growth initiatives and the SDGs through five axes: policy, new economic opportunities from the sustainable use of natural resources, the efficient use of natural capital and energy in production, business and human competences and capacities in STI. In this context, this study seeks to analyse the main contributions and adequate measures that determine the relationships between green growth, SDGs and STI in Colombia over recent years using different econometric models. The results of this study suggest the importance of STI in promoting green growth and achieving SDGs. In other words, higher investments in STI promote lower pollution and higher productivity, competitiveness and development, and new knowledge and technologies are found to be important to increasing the sustainable use of natural resources in productive processes. These results suggest policy implications with regard to energy use and conservation, resource efficiency, and the reduction of pollution. It is important to formulate and frequently measure the indicators of STI related to green growth and SDGs from a baseline, as this will allow us to analyse improvements in competitiveness and productivity from a sustainable development perspective.

Description: Nowadays waste electrical and electronic equipment (WEEE) generation is increasing due to the increase in the number of users and the development of electronic products. In Indonesia, there are no specific regulations about WEEE even though it is identified as hazardous and toxic waste. This study aims to predict the WEEE generation from the most used and replaced electronic products by citizens of Bandung City. The data is collected by surveying 400 families in Bandung City. Based on the survey results, there are three types of electronic products that are most used and replaced by citizens of Bandung City, which are mobile phones, laptops and televisions. The Delay Model is modified by replacing the lifespan variable with end-of-life to project the mobile phones, laptops and televisions waste generation in Bandung City. The purpose of this modification is to adjust the pattern of electronic products used in developing countries. The projection results state that Bandung City will generate 0.61 tons/day of mobile phones, 8.66 tons/day of laptops and 3.16 tons/day of televisions at the end of 2020. Based on the results of the projection, WEEE management and recycling is important which can reduce WEEE disposal and increase the economic value of WEEE.

Description: Energy efficiency policy has been one of the European Union top priorities for decades and will continue to play a vital role in the next 10 years with the introduction of The Clean energy for all Europeans. Likewise, in Latvia energy efficiency has been given high priority; however, the energy efficiency targets for industry has lacked ambitions. This research focuses on evaluating the Latvian industrial energy efficiency policy using top-down approach and benchmarking energy intensity of Latvian industry to the average of the European Union’s. Results confirm that on average Latvian industry consumes 2.6 times more energy to produce the same amount of value added compared to the average in the European Union; however, every saved energy unit in Latvia would save twice less CO2 emissions considering already largely decarbonized energy mix. In the spotlights of the Green Deal proposed by the European Commission, much higher contribution in terms of CO2 reduction and energy efficiency will be expected from the industry. Nevertheless, energy efficiency targets for Latvian industry should be sector-specific, separately addressing CO2 intensive sectors, and non-intensive CO2 sectors with low added value.

Description: Natural ventilation was analysed in a low-income dwelling to control open or closed windows according to a dynamic simulation process in sub-humid warm climate. A selective algorithm to control natural ventilation was determined in an annual period per hour with the following findings: a) an algorithm to select open or closed windows was determined, b) comfort hours per year were evidenced with open, closed windows and selective algorithm to operate natural ventilation, and c) the schedule and periods of ventilation control were presented. Meteonorm® data were used on an hourly basis in Design Builder® simulations and the Meteorological System data based on 30 years of measurements were used to determine the comfort range. Conclusions: the potential benefits to be obtained by applying this ventilation strategy with a selective algorithm are observed in sub-humid warm climate.

Description: This work is a continuation of the article “Methods for Determining the Performance and Efficiency Parameters of the Flue-gas Condenser Sedimentation Tank”. During the experimental determination of Particulate Matter (PM) physical parameters, a described methodology was used. The results obtained affected the choice of water purification technology. Sedimentation technology was selected but provided that a filter element should be present in the installation. The article describes the types of industrial sedimentation tanks used more often. In condition that the system should be compact, while at the same time the purification efficiency rate should be high, the new suitable design of the water treatment system was developed.

Description: Buildings are linked to a significant untapped energy saving potential, accounting for 40 % of European Union’s (EU) final energy and 36 % of CO2 emissions. Energy efficient building envelopes plays the key role to achieve decarbonization of the EU’s building stock by 2050. Active building envelopes are emerging and novel trend offering the paradigm shift in perception of building enclosures. Paper presents study of active solar façade containing phase change material for energy storage. Study seeks for optimisation of solar façade module by introducing dynamic component and variating in the composition of module itself to ensure faster energy harvesting and minimise the heat losses at discharging phase. Comparative tests were carried out in laboratory, in controlled heating and cooling conditions to evaluate impact of dynamic component. The dynamic component has reflective inner coating that focuses solar radiation on the element in heating phase and aerogel insulation filling in the blades that decreases heat loss in the cooling phase. Varying components in the design were used– thickness of aerogel insulation, Fresnel lens and width of concentrating cone diameter. Wide range of phase change material average temperature was observed 24 °C in setups with full aerogel filling to 50 °C in setup Fresnel lens. Average temperature in phase change material was reached higher in all setups with dynamic component compared to identical setups without dynamic component. Temperature differences were in the range from 1 °C in aerogel filled setups till 6 °C in setups with Fresnel lens.

Description: Temperature difference between supply and return distribution medium (water) is a vital factor when assessing the efficiency of a district heating (DH) substation. An accounting for fluctuations and differences of the heat consumption/generation is the key problem in planning DH system operation. The influence of the fluctuating energy consumption on a DH system was studied with actual data, using the DH systems of the Russian cities Krasnoyarsk and Omsk as a case study. Information is visualized in the form of graphs and charts, orderly and clearly comparing certain points. The data includes supply and return temperatures, and heat demand. Clearly visible state of high return temperatures induces more bottleneck problems as the flow increases. At the same time, in 2019, the total heat demand was 21 008 MW. This is more than 5 % than in 2020, assuming 100 % of consumers connected. The reasons for this trend are: decreasing total housing area, no incentive for the buildings in newly built-up areas to be connected to the DH system, poor service motivating business facilities to disconnect from the system. When the primary energy consumption related to the warmer climate and behaviour of business sector decreases, the DH system requires renovation. It is possible to reduce network return temperature during some months of the year. The reason is that, a high temperature difference is essential to maintain high efficiency and minimize fuel and pumping cost, it also enables more customers to be connected to a DH system without increasing pipe dimensions of a network.

Description: Multifunctional agriculture holds several potentials for applying new technologies and innovative processes to reduce its environmental impact in line with the European Green Deal. Though, new cooperation concepts are a sufficient tool to enhance these potentials, using interdisciplinary and cross-border approaches. Hence, Regional Innovation Strategies on Smart Specialization (RIS3) can play a key role on political level to foster regional innovation development on agriculture in rural areas. By analysing Smart Specialization priority areas, potential crossovers between this innovation policy and actual implementation in practice can be deduced for cross-border cooperation approaches. Thus, the conducted research offers a comparison of priorities for German regions involved into the RUBIN program as use cases, supporting rural and less developed regions. Through these introduced use cases and strategy analysis, the inductive and deductive research offers a cross-border cooperation concept for legume food production, exploiting spillover effects to other priorities related to multifunctional agriculture. The core element of the concept is the introduction of knowledge hubs with an interdisciplinary view to enhance and apply innovation potentials in line with RIS3, which create positive effects on the environmental impact from the start with legume as raw materials until an improvement of its product portfolio for consumption at the end.

Description: The integration of district heating (DH) and cooling (DC) in the sustainable energy system of the future requires a significant reduction in operating temperatures. Supply temperatures below 70 °C are required for new 4th Generation DH. Main benefits are the use of low exergy heat sources and the reduction of heat losses. The reduction of heat losses is achieved by reducing the driving temperature difference between the medium pipe and the ground. The decrease of the return temperature level is limited by the consumer behaviour and the ground temperature level. As a consequence, the reduction of the supply temperature is accompanied by a reduction of the maximum transmittable heat flow. For energy efficiency and economic reasons, the relative heat losses are therefore an important design value for DH networks. The study proposes an approach to estimate the relative heat losses by using steady-state heat loss models and analyses the values for different DH generations. In particular, due to the rising of the near-surface soil temperature, the relative cold losses are also studied.

Description: Increasing energy efficiency requirements lead to lower energy consumption in buildings, but at the same time occupants’ influence on the energy balance of the building during the use phase becomes more crucial. The randomness of the building’s occupancy often leads to the mismatch of the predicted and measured energy demand, also called Energy Performance Gap. Therefore, prediction of occupancy is important both in the design and use phases of the building. The goal of the study is to apply Extreme Learning Machine (ELM) models with different optimisation algorithms – Genetic (GA-ELM) and Simulated Annealing (SA–ELM) for occupancy prediction in an office building based on measured CO2 concentrations. Both models show similar and high accuracy of prediction: R2 – 0.73–0.74 and RMSE – 1.8–1.9 for the whole measured period. Influence of population size, number of neurons, and number of iterations on results accuracy was also analysed and recommendations are given. It was concluded that both methods are suitable for occupancy prediction, but because of different simulation times, SA-ELM is recommended for the Building Management Systems (BMS), where higher speed is required.

Description: Municipal solid waste (MSW) management has emerged as one of the major environmental challenges globally. The consequences of inappropriate waste management are manifold and the trend would continue if immediate interventions are not taken for its reversion amid rapid urbanization and current consumption patterns of individuals. The concept of circular economy (CE) can contribute to a paradigm shift in the transformation of the traditional linear approach that does not favour reuse, recycle, recovery concept. Modern and proven waste management practices with collection systems, recycling facilities, sanitary landfills, and waste-to-energy (WtE) and nutrient recovery offer opportunities to improve urban environment through the valorization of waste and by-products in a CE. This study scrutinizes the existing literature on the assessment of circularity and helps to develop a unified circularity framework in the management of MSW in cities. Key aspects such as tools for measuring circularity, nexus and trade-offs, and conditions in promoting CE are discussed. Finally, this paper elucidates the need for circularity, including enablers and inhibitors for promoting circularity in the management of MSW with a case study in the city of Curitiba, Brazil.

Description: Fuel cells (FCs) are among the more efficient solutions to limit the emission of greenhouse gases. Based on the conversion of the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electrical energy, a typical FC produces a voltage of 0.7 V under load. The potential is highly increased by placing the cells in series to obtain a stacked cell. Among the types of FCs, the polymer electrolyte membrane FCs (PEMFCs) are developed mainly for transport applications, because of their low impact on the environment, high power density and light weight compared with other types of FCs. Phosphoric acid (H3PO4) doped polybenzimidazole (PBI) membranes are widely used as efficient electrolytes. The performance of a (high temperature, 130–200 °C) HT-PEMFC depends mainly on the amount of H3PO4 in the solid polymer membrane. The strong autoprotolysis of H3PO4 is responsible for the high proton conductivity also in the anhydrous state. In this study, the H2OH3PO4 system is investigated in the temperature range 60–150 °C with varying water vapour activity at constant atmospheric pressure. Main purpose is to gain more insights into the kinetics of the equilibria in the H2O-H3PO4 system, which influence the fuel cell performance. Density, water content, electrical conductivity and activation energy are determined by exposing H3PO4 solutions for sufficiently long periods to controlled gas atmosphere in order to reach near-equilibrium conditions. The coexistence of ortho- and pyrophosphoric acid is analysed and higher condensed species are also considered. A new setup fully made in quartz is designed and developed to mix the phosphoric acid solutions in a climate chamber. The experimental results are compared to literature data to validate the developed setup and the methodology.