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Considering the global increase in mean air temperature and society’s demand for a comfortable indoor microclimate, cooling solutions in buildings will play an essential role in achieving global climate goals. Researchers estimate that global energy consumption will be significantly affected by the energy required for cooling. Assessment of cooling demand potential is an essential step to further analyse cooling options for buildings in certain areas. Within the framework of this study, mapping of energy consumption for cooling in the city of Riga (Latvia) is carried out. Mapping allows to assess the demand in a spatial perspective, identifying areas with a denser energy demand indicator, and, accordingly, a higher potential for implementation of district cooling and this method can be used in other countries and cities as well. Energy consumption for cooling at the building level was calculated and visualized using cadastral data and building energy certificate data. The results show that the potential energy consumption for cooling in the city of Riga can reach up to 397 GWh per year and the largest proportion of energy consumption for cooling is predicted in the category of multi – apartment buildings (up to 155 GWh per year), highlighting the need to pay particular attention how cooling demand is addressed in residential building sector. Results can be further used to evaluate the technical and economic feasibility of the district cooling implementation in parts of the city.

The TIMES Latvia optimization model was developed to evaluate cost-effective pathways for reaching energy efficiency targets in 2030 and carbon neutrality in the Latvian economy by 2050. The model includes both the end-use sectors such as transport, buildings, industry and agriculture and the energy sector, with a well-developed database of existing and future RES and storage technologies. The modelling framework allows to identify the cost-optimal future energy mix by considering the electrification potential of each sector. Therefore, it allows the analysing of the impact of different policy strategies on sectoral integration levels and the necessity for additional energy storage capacities. The results show that one of the optimal solutions for reaching the energy efficiency targets in 2030 is the wide expansion of heat pump utilization merged with ambitious building renovation policy to increase energy efficiency. The building heat supply transformation also brings higher power consumption and interacts with the wider utilization of wind power. Alternative pathway could rely on increased solar power installation for self-consumption coverage which shows lower costs than building energy efficiency increase.

District Heating and Cooling (DHC) technology is widely recognised as a promising solution for reducing primary energy consumption and emissions. The 5th Generation District Heating and Cooling (5GDHC) network is the latest DHC concept characterised by low-temperature supply, bi-directional heating network operation, decentralised energy flows, and surplus heat sharing. Unlike the 4th Generation District Heating (4GDH) technology, the 5GDHC technology switched to a consumer/prosumer-oriented perspective. The introduction of 5GDHC solutions requires high investments, an important barrier to further developing DHC systems. Therefore, a novel pricing and business model could include introducing co-owners or energy managers into the system. Three different local market business models for 5GDHC at the community level have been tested. The reverse technical and economic simulation has been used for a feasibility study to determine the resources, business models, and combinations closest to the break-even point with lower costs and higher gains for all involved stakeholders.

Even though the development of renewable energy technologies has been one of the most discussed and research-rich fields of science, and there are many practical and convincing technologies in the field of renewable energy, the path taken by society to shift from the use of non-renewable energy sources to the use of renewable ones has often been slow and unclear. Renewable energy technologies have undergone many improvements. There are several successful and promising examples where installing renewable energy technologies has paid off financially and improved the environment and quality of life. Nevertheless, fossil fuel still dominates or makes up a large proportion of energy production. The research simulates existing, planned, and potential policies to assess the best way to integrate renewable and local energy resources into the energy system by 2030 and in the long term. Policy analysis is carried out for several possible combinations of support measures to assess if it is possible to achieve the set targets in the National and Climate plan by 2030 and reach Climate neutrality by 2050. Such an approach makes it possible to assess the impact of existing policies that create synergies or undesirable side effects and whether they maximize the return on investment from a socio-economic and environmental point of view. In addition, a risk analysis and impact assessment of the proposed policy scenarios are carried out using multi-criteria analysis.

The transport sector accounts for about one-third of the final energy consumption in Latvia, most of which are fossil fuels in road transport. Fossil fuel consumption increases emissions and demands an immediate change in mobility habits to achieve climate neutrality by 2050. This paper focuses on the in-depth analyses of passenger transport by modelling the potential use of cleaner energy sources and the possible decrease of consumption through the modal shift. As travel modes differ for each distance, the study is done for three distances – short, medium and long. Three scenarios have been analysed – BASE scenario including existing measures and taxation policy, NECP scenario including measures defined in the National Energy and Climate Plan until 2030 and GHG TARGET scenario aiming to achieve climate neutrality by 2050. The proposed modelling approach allows for the development and evaluation of the effectiveness of existing and planned measures in greening mobility. Results proved the need for immediate action and a change in the mobility habits of the population to achieve climate neutrality by 2050.

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.

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.

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.

Europe has a course to zero emissions by 2050, with a strong emphasis on energy sector. Due to climatic conditions in Latvia, district heating (DH) plays an important role in the energy sector. One of the solutions to achieve the set goals in DH is to introduce emission-free technology. Therefore, the popularity of installation of large-scale solar collector plants continues to increase in DH in Europe. The first large-scale solar collector field in the Baltic States was installed in 2019. Solar collector active area is 21 672 m2 with heat storage water tank 8000 m3. The article shows the first operation results of this system and evaluates influencing factors. The results of the analysis show that system productivity is mainly demanded by solar radiation, and the strongest correlation between these parameters were established in May. The highest correlation between ambient air temperature and produced thermal energy is reached when ambient air temperature is between 7 °C to 15 °C and production process has not been externally regulated. The temperature difference between flow and return temperatures of the heat carrier affect solar collector performance minimally and strong correlation was not observed.

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).

Renewable energy sources are expanding opportunities for industrial development and can boost economic growth and create new jobs. In all European Union (EU) countries, including Latvia, it is possible to use renewable energy resources cost-effectively. The world is now at the beginning of the global energy transformation. Cost-effective renewable energy technologies provided an opportunity for sufficient development to reach ambitious climate targets of the EU Directive 2009/28/EC. Some systems are not only dependent on the interaction of many elements and dynamics over time, but they are also variable in space. In this context, energy production from local and renewable resources is one of the most relevant examples. It is characterized by many spatially variable elements, such as biomass availability, wind speed, solar radiation, location of power plants, transmission network infrastructure, energy demand, etc. It is crucial to explore the spatial distribution of resources to plan territorially-unified development of renewable energy and, consequently, promote efficient use of resources. This paper describes the data acquisition process of the spatial distribution of renewable energy sources. ArcGIS PRO and data collected from the various databases were used to describe the energy sectors according to resources, spheres of consumption and regions.

The transition from a fossil fuel-based energy system to renewable energy sources has become a crucial consideration in both national-scale planning processes and local-scale energy system planning. Research has been conducted to seek technical solutions for a specific district of a university campus located on the peninsula of Riga to implement a smart energy system with multiple energy sources, storage systems, and energy efficiency measures. The solutions for the transformation toward a positive energy district include power generation by building integrated solar panels with different power storage alternatives, such as thermal storage, batteries, hydrogen, and fuel cells. The simulation also evaluates the potential for heat recovery and waste heat integration from the data centre and cooling systems to cover the heat demand. The interlinkage with energy efficiency improvements through improved building management systems provides an opportunity to increase RES utilization rates and improve overall energy efficiency. To provide a holistic overview of the future development of the urban area, the research also compares the connection to the district heating network. Results show that the analysed district can achieve up to 80% of the RES self-consumption level as cost-optimal solutions by combining off-site wind turbine, solar PV panels, water source heat pumps, waste heat recovery and adjusted power storage. [ABSTRACT FROM AUTHOR]

New district heating system technologies have arisen in the last years to deliver economic and environmental benefits to residential and commercial buildings. The extensive ranges of equipment, energy sources, temperature profile configurations, size of the network, energy demand, and many other intrinsic variables, make it difficult to identify if a determined district heating option is potentially better than another in environmental terms. As for the economic evaluation, there are several tools decision-makers can rely on to assess environmental performance. The main challenge is to provide a holistic point of view for which lifespan and complexity of implementable, new technological systems can be an obstacle. For this reason, in this paper, a Life Cycle Assessment is performed upon a technical evaluation of several district heating configuration options for the Gulbene region in Latvia, where DH systems in most of the assessed parishes are already operating under medium temperature regimes, also known as third-generation district heating. The goal of the study is to understand the environmental impact of moving from the current DH system to a low temperature one. Results show a considerable environmental benefit if low-temperature profiles, combined with the use of renewable energy sources are adopted in the current DH systems. A hotspot analysis is also performed showing the use stage is the one carrying most of the burden across the project’s lifetime, followed by infrastructure construction; also showing that the refurbishment of buildings does not play a major role in the total environmental impact contribution.

National energy sector management differs from country to country. Therefore, it is important to develop country-specific energy models to analyse the energy demand, structure and potential policy instruments. The paper presents a pathway for adaption and improvement of the standard TIMES model structure to the specific country requirements. The analysis is based on a three-sector (industrial, commercial and residential) case study of Latvia. Literature review presents experience of other research when developing different energy models as well as adapting the TIMES model structure. The main results show a distribution of the final energy consumption and the validation of the obtained results of the sectors studied. Method and intermediate results presented in the paper are part of an ongoing modelling process of Latvia’s energy sector.

District heating (DH) has been highlighted as an important part in future carbon neutral energy supply. However, the performance of different DH systems varies a lot and the existing regulations do not always motivate DH companies to move toward more sustainable heat production. Therefore, this article presents novel methodology for Climate index determination which can be further used for the comparison of DH systems. The Climate index includes seven different indicators which show DH system performance according to energy efficiency, sustainability and environmental impact dimensions. The methodology is applied for 20 different DH systems operating in Latvia. The results show that the performance of 5 natural gas-based DH systems is below the determined climate benchmark.

Solar technologies are flexible and can be used for both centralized and decentralized energy production. The main aim of this article is to compare different solar technologies and configurations for integration into the DH system. The multi-criteria analyses method is used to rank different alternatives based on several criterions. The evaluation of criterions has been based on previous studies conducted. The multi-criteria analyses allow to compare different solar system alternatives that cannot be compared directly due to differences in their scale, type of energy produced and consumed, investment levels, etc. For the particular DH system researched, the most desirable solution is the PVT panel integration with an area of 1000 m2 which is aligned with the actual DH company’s power consumption. However, the results are strongly impacted by the assumed investment levels, efficiency of the technologies and other assumptions that could be further analysed by the help of sensitivity analyses.

Sustainable heating solutions involving renewable energy sources and low supply/return temperatures for district heating are evolving. Low temperature use in district heating allows reducing the heating operation costs significantly and at the same time holding the sustainability criteria. However, an in-depth study on environmental impacts during the life cycle of low temperature district heating was not conducted until now. Thus, this study aims to find the best development scenarios for development of local low temperature district heating. For this purpose, a methodology adopts life cycle analysis approach that allows assessing the environmental impacts according to a variety of environmental performance criterions. The results of the study showed an improvement in the overall environmental performance towards the transition of a conventional 3rd generation district heating to low temperature concept including the effects of reconstruction and modernization of the boiler house. A set of potential development is proposed. Specifically, the scenario implementing low temperature district heating with solar PV showed the best score for environmental performance. The scenario with implementation of low temperature district heating without solar PV did not show significant improvement in environmental performance under operation conditions of a pilot case study.

The district heating (DH) system consists of three basic elements – a heat source, heating network and heat consumers. All of these elements have a definite role in the overall development of the DH system. The transition to 4th generation DH (4GDH) involves changes in each of those elements that interact with each other. Therefore, various related processes form the potential energy savings and reduction of CO2 emissions when introducing 4GDH as whole system in all elements. To estimate the potential outcome from such projects it requires complex engineering calculations, which is not always possible without relevant expertise. The article describes a novel simplified methodology for evaluating the potential GHG emission reduction when implementing 4GDH. Thus, it is proposed to use a simplified calculation formula from linear regression model for the calculation of CO2 reduction.

To recover thermal energy from different sources, its quality and possibilities for utilisation are essential. The wide range of engineering solutions includes a direct connection to the district heating (DH) system and the integration of low-quality heat using heat pumps to increase the temperature level of recoverable heat. Therefore, this article compares waste heat valorisation strategies for integration into existing DH networks, low-temperature DH, and ultra-low heat supply systems using the multi-criteria assessment method. In addition, a local scale assessment was performed to identify the waste heat role in existing RES-based DH systems. The results show that the highest waste heat valorisation rate could be reached when integrated into low-temperature DH systems due to high waste heat potential and suitable temperature conditions. However, a local scale assessment shows a significant impact on the already implemented solar technologies, as waste heat could cover around 70% of the summer heat load. [ABSTRACT FROM AUTHOR]