District Heating Sector Research Articles

Large-scale forest-based biofuels production: Impacts on the Nordic energy sector

The need for fossil-free fuels in transportation will likely cause increased demand for liquid biofuels, which will affect biomass prices and hence alter fuel usage for heat and power generation. Despite obvious connections, the interactions between the forest, bioenergy and energy sectors are only analyzed to a limited extent in previous research. This study analyzes how increased forest-based biofuel production influences fuel use in the Nordic district heating sector, as well as power prices and investments in renewable power production. The novel contribution of the study is the linking of a detailed energy system model and a forest sector model covering forestry and forest industries in the Nordic countries. For the Nordic region, the use of biomass for power and heat is reduced by more than 50% when the biofuel production is assumed to increase from 0 to a 40% share of the transportation fuel market. The results contribute to the understanding of how large-scale biofuel deployment may affect heat and power markets and, in turn, the development of renewable energy systems. Policies targeting the enhancement of specific uses of biomass should take these market effects in the bioenergy and energy markets into account.

Role of power to liquids and biomass to liquids in a nearly renewable energy system

In order to achieve significant greenhouse gas emission reductions, decarbonisation of all economic sectors must be considered. Here, the authors study the provision of renewable energy for the power, district heating, transport and industrial sectors in nine North European countries by integrating a large amount of wind and solar power into the system with power-to-gas and power-to-fuel plants enabling balancing and sector coupling. Simultaneous optimisation of plant capacities and operation was performed. Two different synthetic liquid fuel production pathways were compared. The cost of synthetic liquid fuel remained, depending on the production pathway and amount, 30-120% higher than estimated fossil alternative cost. Biomass potential emerged as a limiting factor with high shares of biomass-based synthetic liquid fuel production. The need for energy storage system was estimated. The total optimal capacity of synthetic natural gas, hydrogen, synthetic liquid fuel, and heat storages varied between 37 and 54 TWh (1.7-2.5% of energy demand) depending on the scenario, when emergency stocks were not included. The cost of energy storages remained small compared to the total system cost, with heat storages exhibiting the highest cost.

Analysis of different scenarios and sustainability measurement in the district heating sector in Serbia

The district heating system in Serbia, with an installed capacity of 6600 MW, currently supplies 58 towns with thermal energy. As a candidate country for accession to the European Union, Serbia faces the obligation to reduce the level of its GHG emissions as part of environmental reforms. This paper presents a basic scenario and three alternatives for final energy consumption in the district heating sector for the years 2015, 2020, and 2025. It is suggested that demand for heating will increase 10% up to 2020 and by 15% up to 2025, in relation to 2015 levels, while the share of each energy carrier will not change. Changing the structure of energy sources for heat supply assumes a decrease in the share of coal and liquid fuel, and increases in the use of biomass and natural gas. The results obtained were compared to the General Index of Sustainability which is a measure of the complexity of the proposed energy scenario. The paper considers the formation of related energy indicators as quantitative tools for the analysis of changes. It also proposes a methodology for multi-criteria analysis in the sustainability assessment of complex energy systems based on the stochastic evaluation of criteria (sets of indicators and sub-indicators). In this way, the results of the multi-criteria assessment can help in the decision-making process in cases where economic, social and ecological criteria are considered to be influential.

Інституц ійне забезпечення державного регулювання у сфері комунальних послуг: на прикладі сектора централізованого теплопостачання в Україні

Інституц ійне забезпечення державного регулювання у сфері комунальних послуг: на прикладі сектора централізованого теплопостачання в Україні

Automated Statistical Methods for Fault Detection in District Heating Customer Installations

In order to develop more sustainable district heating systems, the district heating sector is currently trying to increase the energy efficiency of these systems. One way of doing so is to identify customer installations in the systems that have poor cooling performance. This study aimed to develop an algorithm that was able to detect the poorly performing installations automatically using meter readings from the installations. The algorithm was developed using statistical methods and was tested on a data set consisting of data from 3000 installations located in a district heating system in Sweden. As many as 1273 installations were identified by the algorithm as having poor cooling performance. This clearly shows that it is of major interest to the district heating companies to identify the installations with poor cooling performance rapidly and automatically, in order to rectify them as soon as possible.

Third-party access in district heating: Lithuanian case analysis

Transition from monopoly to competition-based markets is widely recognized processes around the globe when it comes to achieving efficient electricity and gas trade thus presenting direct benefits to the final energy consumers. But when talking about smaller infrastructures like district heating (DH) market is still viewed as a natural monopoly. This article presents Lithuanian case to open up existing municipal infrastructure to third-party access in order to complete fuel switch in DH generation faster and to increase efficiency of the entire system through competitive pressure. The article presents the set of circumstances in DH sector back in 2010; focuses on regulatory framework, which was developed and introduced through two phases in Lithuania; and formulates impacts of the reorganization of DH sector from vertically integrated monopoly to single buyer model for de-monopolized generation.

Method for allocation of carbon dioxide emissions from waste incineration which includes energy recovery

Presently, waste is regarded as any other fuel in the Swedish district heating (DH) plants where it is treated in combination with energy recovery. Consequently, all carbon dioxide (CO2) emissions that occur during waste treatment are allocated to DH producers even though two simultaneous services are provided – waste treatment and energy recovery. As the focus today is on phasing out fossil fuels from Swedish DH sector, energy recovery from waste turns out to be less desirable than heat production using biofuel and renewable electricity. This article discusses whether the existing allocation method of CO2 emissions contributes to sustainable development and if it does not, to recommend a new method that will. To do this type of assessment, we used the principles from Framework for Strategic Sustainable Development. Results showed that the existing allocation method does not consider the problem of waste generation. The method shifts the responsibility from waste producers to DH customers. To prevent this ‘burden shifting’, a broader system perspective and an upstream approach should be applied. In addition, the method should be designed in ways that would give incentives to responsible stakeholders to act properly, which requires identifying the reasons why waste is not being recycled and to find a way to apply the allocation. Considering resource efficiency, waste treatment through combustion should always include energy recovery. To encourage energy recovery, the produced heat should not be burdened with CO2 emissions.

How to develop district heating in Finland?

District heating is widely used in Finland. About half of the population live is district-heated buildings. Additionally, many industrial and public buildings are heated with district heat. In Finland, district heating is implemented efficiently. Average network and measuring losses are 10%. Through energy transition, urbanization and digitalization the Finnish district heating sector is facing new challenges.This paper deals with how Finnish district heating should be developed during the next five years. Altogether 29 organizations, mainly companies, were interviewed and asked about the main challenges, the main opportunities, the foreseen vision and the required actions. Increased competition forces the energy companies to reconsider their business. The major development efforts should be focused on new production alternatives (including hybrid systems), services and data utilization. The development should also be performed in closer connection with the end users and clients. The new systems and solutions should be piloted in order to ensure their operation and to demonstrate their benefits. The municipalities should take a forerunner role in the piloting actions.

Monopoly regulation when customers need to make sunk investments: evidence from the Swedish district heating sector

Regulatory agencies routinely seek to promote price stability. A rationale for this practise might be that regulators seek to protect customers’ relationship-specific sunk investments. We develop a simple model which confirms that commitments to future rigid prices may increase welfare when customers need to make such investments. We use data from the Swedish district heating sector during the 1998–2007 period to explore the impact of monopoly pricing decisions on the take-up rate of district heating.

Challenges for business change in district heating

BackgroundThe Swedish district heating sector is successfully transitioning to a low-carbon energy system. The industry has expanded since the 1950s and currently meets more than half the Swedish heat demand. The heat market was deregulated in 1996, and thereafter, companies have been exposed to an increasing number of challenges related to technology, institutional factors and market. Since municipal ownership dominates, municipal companies must manage these challenges to ensure future competitiveness. However, theory suggests that business change is difficult when the current model is still working. To date, Swedish district heating companies have revisited their price models and customer perceptions. There is limited knowledge on how the business challenges are managed and on the management strategy’s impact on the business. In this paper, new knowledge is generated regarding how the customer and resource-oriented sides of the municipally owned district heating business in Sweden are changing.MethodsA case study approach was adopted. Data were collected by interviews and by review of the national research programme on district heating (Fjärrsyn). The programme served as a proxy for frontline research on Swedish district heating. The data were analyzed through the business model canvas framework.ResultsChanges to meet external pressures are identified on the customer side of the business model, but changes are also spreading to other parts of it. However, the key resource component (distribution networks and production unit) and its logic of economics of scale are unchanged and dominate. The logic is not compatible with shrinking heat demand; nevertheless, it is preferred.ConclusionsIt is concluded that external challenges have resulted in changes in the customer side of the business model. However, the largest challenge is the transformation of key resources. Accounting for external challenges extends the life of the current business model, but it is not increasing competitiveness. The prolonged life creates a window of opportunity for the companies to begin the needed transformation of their key resources. If the transformation is successful, district heating will have a role in the future energy system. If the transformation is not undertaken, the future is less certain.

Development of an empirical method for determination of thermal conductivity and heat loss for pre-insulated plastic bonded twin pipe systems

Pre-insulated twin pipe systems (PTPS) for heat distribution offer advantages for heat supply companies. Trench dimensions for heat supply systems of District Heating (DH) networks might be reduced using these pipe systems. This reduces costs in civil engineering. Additionally heat loss of the DH network may be reduced, that decreases operational costs of these systems. On the other hand, operational heat losses of PTPS significantly differ in many cases from theoretical heat loss of PTPS. This may inhibit the application of this technology in DH networks.Against this background, a standard measurement procedure of thermal properties of PTPS shall be developed, validated and tested at FFI. These tests shall be based on standard measurement procedures for single pipe systems described in EN ISO 8497 and modified for PTPS. Within this context, preliminary tests are done at FFI. Numerical simulations of heat loss are done at IGTH and iteratively fitted to data generated from measurements at the same time.Numerical simulations of stresses occurring due to operational temperatures for PTPS are done in a second step. Internal stresses due to temperature gradients within PTPS as well as external stresses due to interactions of PTPS with the bedding material and ground will be examined. In addition, interactions of bedding materials, operational conditions and heat losses in situ will be assessed.First results obtained are presented in this paper. Focus of this paper is on development of a standard measurement procedure for thermal properties of PTPS, as well as results of numerical calculations regarding heat loss of these systems. One goal of this project funded by the “BMWi – Federal Ministry for Economic Affairs and Energy”, is to discuss and mirror project results in order to modify existing standards, e.g. EN 15698, EN 15632 and EN 13941. Defined quality standards for PTPS, verified by standardized measurement procedures for PTPS, will increase the acceptance of PTPS in the DH sector. This supports small and medium sized enterprises (SME) using and producing PTPS.

Simulation method for a pit seasonal thermal energy storage system with a heat pump in a district heating system

To better facilitate renewable energy systems, the district heating sector is currently changing towards lower temperatures and increased cross-sectoral integration. Seasonal thermal energy storage systems alongside heat pumps have received an increasing attention. However, the operation of a seasonal thermal energy storage system alongside a heat pump is more complex than a short-term thermal energy storage system, and as such, several complex simulation models have been developed. These models have shown to be usable for simulating the operation, but due to their complexity are difficult to implement in simulation models that focus on overall energy system analyses. Based on the operation of an existing seasonal thermal energy storage system, this paper provides a simulation method for a seasonal thermal energy storage system with a heat pump that can be utilized in overall energy system simulation models. The simulation method is based on the proven different operational situations of the seasonal thermal energy storage system. The method is shown to be able to approximate the actual operation on an hourly basis and the yearly thermal losses.

Framework conditions for Nordic district heating - Similarities and differences, and why Norway sticks out

The district heating (DH) sectors differ considerably among the Nordic countries: DH is an important contributor to heat supply in Denmark, Finland and Sweden, but in Norway it plays only a minor role. In this study, we compare historical, economic, jurisdictional, political and geographical framework conditions for DH and assess their impacts on the development of DH in the Nordic region. DH is subject to national and municipal regulations, with tax and subsidy schemes that are complex and vary between the countries. The total fuel prices induce differences in fuel distribution. Electricity is competitive, both in DH and individual heating in Norway. This study further suggests, by comparing the impacts and implications of differences in cost components in a model plant, that differences in profitability is currently small between the Nordic countries. However, historical and geographical factors, such as local commitment and differences in infrastructure, constitute the major difference in the penetration of DH. Adaptability, in terms of fuel flexibility, is important for the industry's survivability and electricity prices are crucial for the development of DH. Energy efficiency measures and competition from residential heat pumps are the industry's largest challenges.

Market Power With Combined Heat and Power Production in the Nordic Energy System

The trend toward increasing energy efficiency and variable renewable energy (VRE) production has implications for combined heat and power (CHP) plants, which operate in both the price-driven power market and the district heating (DH) sector. Since CHP will be important in VRE integration, we develop a complementarity model to analyze CHP producers’ roles in integrated markets. We use a Nordic case study to gain insights into, first, the effect of the link between CHP and DH on market power and, second, market power's impact on operations in the DH sector. The results indicate that, first, the link of CHP to DH supply can increase market power and, second, market power can induce shifts in DH production from heat only to CHP.

Power-to-gas plants in a future Nordic district heating system

Power-to-gas (P2G) technology has been suggested as one way to balance the variability of renewable power generation and decarbonize the transport sector. This paper studies the application of P2G plant in a real Finnish municipal district heating system in a future situation where the European power and district heating sectors have been decarbonized. From the point of view of the district heating company, the P2G plant can act as fuel producer, CO2 sink and heat source.The district heating unit commitment (DHUC) model was used to optimize the full-year hourly resolved operation of a CHP CCS plant, heat boilers, heat pumps, P2G plant and heat storages. Capacity optimization of most plants was also done. The hourly power price variability was obtained from regional unit commitment and economic dispatch simulation of the North European region. We find that a P2G plant may be profitable in the system, starting with SNG value of 70 €/MWh and depending on the specific investment. The regional simulations show that the market value of SNG is greater than this, and we conclude that P2G is a viable option.

Environmental impact of energy refurbishment of buildings within different district heating systems

The refurbishment of existing buildings is often considered a way to reduce energy use and CO2 emissions in the building stock. This study analyses the primary energy and CO2 impact of refurbishing a multi-family house with different refurbishment packages, given various district heating systems. Four models of typical district heating systems were defined to represent the Swedish district heating sector. The refurbishment packages were chosen to represent typical, yet innovative ways to improve the energy efficiency and indoor climate of a multi-family house. The study was made from a system perspective, including the valuation of changes in electricity use on the margin. The results show a significant difference in primary energy use for the different refurbishment packages, depending on both the package itself as well as the type of district heating system. While the packages with heat pumps had the lowest final energy use per m2 of floor area, air heat recovery proved to reduce primary energy use and emissions of CO2-equivalents more, independent of the type of district heating system, as it leads to a smaller increase in electricity use.

Identification of Individual District Heating Network Conditions using Equivalent Full Load Cycles

Repeated loading in district heating networks is occurring inconstantly. There are small and great load amplitudes in the system. As small load amplitudes are usually observed more frequently than great load amplitudes, their accumulation with respect to great load amplitudes is of common interest. A growing share of renewable energy can be noted in energy markets. Because of this, flexible operation of combined heat and power plants is necessary. For the connected district heating network this means additional temperature amplitudes in the system, causing higher stresses for the network. Repeated loading in the system has to be considered in the fatigue analysis. For a suggested lifetime of a district heating network of 30 years, an estimated number of cycles for the temperature load were accumulated for standardization. Nevertheless a longer lifetime than 30 years for district heating pipes is expected in the district heating sector, which also means higher cyclic loading. Due to individual operation parameters and individual network conditions, the equivalent action cycles are expected to be different at every element in the network. The paper is based on a review on damage accumulation theories that may be used for district heating systems regarding future developments. Some examples are shown for equivalent full load cycles for different locations in district heating networks.

Primary energy factor for district heating networks in European Union member states

The use of Primary Energy Factor (PEF) was chosen by European Union policy makers as an obligatory part of methodology for comparing the primary energy consumption of products, using different energy sources.Approaches for definition of primary energy differ in EU member states. Different methodologies and definitions of primary energy factors have impact on calculation of energy sector key indicators, including district heating (DH) sector. The aim of the research was collection, analysis and systematization of data about PEF and its calculation and definition methods for DH in EU Member states.Method used for data collection about EU Member States with adequate share of DH in heat supply is meta-analysis systematic review methodological approach, using as main data sources legislation and standards currently in force, which are used to regulate implementation of PEF in EU Member States with adequate share of DH in heat supply.The main criterion for the classification of DH PEF in different countries is PEF determination procedure. Based on this criterion three main groups were analysed: single fixed DH PEF, differentiated DH PEFs, DH PEF, calculated for each DH network independently.

Mapping energy and exergy flows of district heating in Sweden

District heating has been available in Sweden since the 1950s and used more than half of the total energy use in dwelling and no-residential premises in 2013. Energy and exergy efficient conversion and energy resources are key factors to reduce the environmental impact. It is important to understand energy and exergy flows from both the supply and demand sides. The exergy method is also a useful tool for exploring the goal of more efficient energy-resource use. Sankey diagrams together with energy and exergy analyses are presented to help policy/decision makers and others to better understand energy and exergy flows from primary energy resource to end use. The results show the most efficient heating method in current district heating systems, and the use of renewable energy resources in Sweden. It is exergy inefficient to use fossil fuels to generate low quality heat. However, renewable energies, such as geothermal and solar heating with relative low quality, make it more exergy efficient. Currently, about 90% of the energy sources in the Swedish district heating sector have an origin from non-fossil fuels. Combined heat and power is an efficient simultaneous generator of electricity and heat as well as heat pump with considering electricity production. Higher temperature distribution networks give more distribution losses, especially in exergy content. An outlook for future efficient district heating systems is also presented.

Characteristics of large thermal energy storage systems in Poland

In District Heating Systems (DHS) there are significant fluctuations in demand for heat by consumers during both the heating and the summer seasons. These variations are considered primarily in the 24-hour time horizon. These problems are aggravated further if the DHS is supplied by a CHP plant, because fluctuations in heat demand adversely affect to a significant degree the stable production of electricity at high overall efficiency. Therefore, introducing Thermal Energy Storage (TES) would be highly recommended on these grounds alone. The characteristics of Large (i.e. over 10 000 m 3 ) TES in operation in Poland are presented. Information is given regarding new projects (currently in design or construction) that apply TES technology in DHS in Poland. The paper looks at the methodology used in Poland to select the TES system for a particular DHS, i.e., procedure for calculating capacity of the TES tank and the system to prevent water stored in the tank from absorbing oxygen from atmospheric air. Implementation of TES in DHS is treated as a recommended technology in the Polish District Heating sector. This technology offers great opportunities to improve the operating conditions of DHS, cutting energy production costs and emissions of pollutants to the atmosphere.