Planning of district heating regions in Estonia

It is quite evident that district heating networks will continue to be developed in order to complete their transition towards the 4th generation district heating by decreasing heat losses, increasing the share of renewable and waste heat sources, and integrating energy storage units and smart operating solutions. The significance of district heating in Estonia is very high, and developing this sector is very important for achieving climate and energy targets set by Estonia. Consumers play important role in the transition process, and for the purpose of informing and educating consumers, a district heating promo app has been implemented at the national level. One of the app’s modules shows consumers the energy mix that will be required to supply heat via district heating in the future, with all of the planned changes and different district heating regions taken into account. Measures and goals proposed in the Estonian National Development Plan of the Energy Sector until 2030, as well as all available heating strategies from various district heating regions have also been considered. The algorithm of the methodology takes into account possible changes in heating demand caused by increased energy efficiency of the building sector, heat loss reduction due to renovation of existing DH networks and possible reduction of DH temperature, as well as increase in the share of renewable energy sources and its impact on primary energy consumption and CO2 emissions in DH area.  Scenarios show which fuel/primary energy mix is expected to be used for heat generation in the future (the data is given for each district heating region), as well as the amount of CO2 emissions. Several typical case studies are also provided

Low temperature district heating: An expert opinion survey

Among the available solutions for building heating and cooling, district heating (DH) and district cooling (DC) systems are considered some of the best options since they can ensure a better control of pollutant emissions and greater efficiency than individual systems. Nevertheless, improvements are needed to increase their sustainability and reliability. The so-called \u201clow temperature district heating\u201d (LTDH) concept has been introduced in recent years in an attempt i) to reduce the distribution heat losses through a temperature decrease in the DH network, ii) to favor the integration with renewable energy sources, and iii) to create the conditions required for the development of future smart energy systems. However, many concerns have been raised about its implementation in both existing and new systems. For this reason, this paper aims to identify the stakeholders\u2019 ranking of the barriers against LTDH system development and implementation over the next few years. Aiming to this, a questionnaire was designed, including an analysis of current gaps and strengths, and then submitted to more than 50 Italian and international experts in the field of DH. An in-depth analysis of the received answers was performed, focusing in particular on the Italian experts\u2019 answers. Comments and suggestions on how to promote the transition to the new LTDH approach are reported

Modelling framework for integration of large-scale heat pumps in district heating using low-temperature heat sources: A case study of Tallinn, Estonia

The paper presents a modelling framework that may be used to plan the integration of large-scale HPs in district heating (DH) areas. By use of the methodology both optimal HP capacities to be installed and optimal choice of heat source to be used during the year are identified by minimizing total cost of ownership including investment and operational costs. The modelling framework uses mixed-integer linear programming and hourly calculations over one year. Seasonal variations of the heat source temperatures, capacity limitations and HP coefficient of performance as well as technical constraints were taken into account. The DH network of Tallinn, Estonia, was used as a case study. Six different heat source types were identified for 13 potential locations of large-scale HPs. The results showed that the integration of large-scale HPs in the DH network of Tallinn is economically feasible. It was found that 122 MW HP capacity could be installed without compromising the operation of sustainable base load units. The heat sources needed for obtaining this solution were sewage water, river water, ambient air, seawater and groundwater. It was further shown that the Lorenz efficiency depends on the variations of heat source temperatures

Heat pumps for domestic heating: A techno-economic exploration of comparative advantages of individual scale versus district level

A thorough understanding of heat demand is essential for evaluating strategic options to design, plan, and implement future low-carbon heat technologies. Electric heat pumps and decarbonised electricity have been proposed as promising alternatives that could replace gas heating and contribute to the future low-carbon heat mix. District heating has been transformed over several generations to better use renewable sources rather than fossil fuels to meet heat demand. Both technologies are well developed over the past few decades due to a significant amount of scientific research and industrial experience. However, the markets and supply chains for heat pumps and district heating networks are immature in the UK. There are technical, social, and economic factors that present challenges for their deployment. This research offers insights into energy load profiles and peak demand based on data in various types of British dwellings from the largest smart meter field trial. It quantifies energy consumption in dwellings and the aggregated peak demand under cold weather events. This provides an empirical basis for evaluating potential low-carbon heat technologies to replace the existing prevalent gas-fired domestic heating systems. This research investigates the role of heat pumps and district heating by assessing the topological configurations of heat pumps and district heating networks at different scales through techno-economic modelling, in order to explore their comparative advantages from different perspectives, including technical performance, carbon emissions, and cost-competitiveness. This study demonstrates the economies of scales of heat pumps and district heating, and it highlights the advantages of using heat pumps and district heating to reduce carbon emissions via utilising low-carbon electricity and heat sources that would otherwise be wasted