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| 2. |
- Averfalk, Helge, 1988-, et al.
(författare)
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Klimatgaser i Halland – en målinriktad analys med framtidsperspektiv
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten innehåller en analys av utsläppen av de sex klimatgaserna i Halland mellan 1990 och 2011, en skattning vad som kommer att genomföras till 2020 och förslag till åtgärder för att kunna leverera utsläppsreduktioner efter 2020. Resultaten visar att de halländska utsläppen har minskat med 20 procent sedan 1990, målet om 27 procent lägre utsläpp till 2020 kommer troligen att uppnås, transporter och jordbruk måste kunna leverera utsläppsreduktioner efter 2020, regionala plan- och styrdokument måste i större utsträckning kunna kvantifiera framtida utsläppsreduktioner samt att det behövs ett regionalt kompetenscenter i Halland för att länet ska kunna leverera utsläppsreduktioner i framtiden.
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| 3. |
- Averfalk, Helge, 1988-, et al.
(författare)
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On the use of surplus electricity in district heating systems
- 2014
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Ingår i: Proceedings from the 14th International Symposium on District Heating and Cooling. - Stockholm : Swedish District Heating Association. - 9789185775248 ; , s. 469-474
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Konferensbidrag (refereegranskat)abstract
- Maintained balance between supply and demand is a fundamental prerequisite for proper operation of electric power grids. For this end, power systems rely on accessibility to various balancing technologies and solutions by which fluctuations in supply and demand can be promptly met. In this paper, balancing approaches in the case of surplus electricity supply, due to long-term, seasonal, or short-term causes, are discussed on the basis mainly of compiled experiences from the Swedish national power grid. In Sweden, a structural long-term electricity surplus was created in the 1980s when several new nuclear plants were commissioned and built. One of four explicit domestic power-to-heat solutions initiated to maximize the utilization of this surplus electricity, as export capacities were limited, was the introduction of large scale electric boilers and compressor heat pumps in district heating systems. In retrospective, this solution not only satisfied the primary objective by providing additional electricity demand to balance the power grid, but represents today – from an energy systems perspective – a contemporary example of increased system flexibility by the attainment of higher integration levels between power and heat sectors. As European power supply will be reshaped to include higher proportions of fluctuating supply technologies (e.g. wind and solar), causing occasional but recurring short-term electricity surpluses, the unique Swedish experiences may provide valuable input in the development of rational responses to future balancing challenges. The main conclusions from this study are that district heating systems can add additional balancing capabilities to power systems, if equipped with electrical heat supply technologies, hereby contributing to higher energy system flexibility. Consequently, district heating systems also have a discrete but key role in the continued integration of renewable intermittent power supply technologies in the future European energy system.
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| 4. |
- Connolly, David, et al.
(författare)
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Heat Roadmap Europe : Combining district heating with heat savings to decarbonise the EU energy system
- 2014
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Ingår i: Energy Policy. - London : Elsevier. - 0301-4215 .- 1873-6777. ; 65, s. 475-489
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Tidskriftsartikel (refereegranskat)abstract
- Six different strategies have recently been proposed for the European Union (EU) energy system in the European Commission’s report, Energy Roadmap 2050. The objective for these strategies is to identify how the EU can reach its target of an 80% reduction in annual greenhouse gas emissions in 2050 compared to 1990 levels. None of these scenarios involve the large-scale implementation of district heating, but instead they focus on the electrification of the heating sector (primarily using heat pumps) and/or the large-scale implementation of electricity and heat savings. In this paper, the potential for district heating in the EU between now and 2050 is identified, based on extensive and detailed mapping of the EU heat demand and various supply options. Subsequently, a new ‘district heating plus heat savings’ scenario is technically and economically assessed from an energy systems perspective. The results indicate that with district heating, the EU energy system will be able to achieve the same reductions in primary energy supply and carbon dioxide emissions as the existing alternatives proposed. However, with district heating, these goals can be achieved at a lower cost, with heating and cooling costs reduced by approximately 15%. © 2013 Elsevier Ltd.
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| 5. |
- Connolly, David, et al.
(författare)
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Heat Roadmap Europe 2050 : Second Pre-study for the EU27
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible. In these strategies, the role of district heating has never been fully explored system, nor have the benefits of district heating been quantified at the EU level. This study combines the mapping of local heat demands and local heat supplies across the EU27. Using this local knowledge, new district heating potentials are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emission targets by 2050, but at a cheaper price than a scenario which focuses primarily on the implementation of heat savings.
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| 6. |
- Connolly, David, et al.
(författare)
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Heat Roadmap Europe 2050 : First Pre-study for the EU27
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This pre-study presents the findings concerning a considerable outlined expansion of the district heating sector within the current EU27 member states until 2050. Heat deliveries are presumed to grow by a factor of 2.1 until 2030 and by a factor of 3.3 until 2050.The current energy policy context is that the latest energy communication from the European Commission (Energy Roadmap 2050) contains only a very modest growth in the future for district heating systems and additional industrial heat use from industrial CHP plants. A small increase is foreseen for industrial demands, while heat deliveries to the residential and service sectors are expected to decrease. In total, the heat delivered is expected to increase by less than one per cent per year, giving a total increase of 20% until 2030 and of 40% until 2050.In this prestudy, more ambitious growth rates are assessed for district heating in the EU27 between 2010 and 2050. The chosen methodology in this pre-study contains a combination of hour-by-hour energy modelling of the EU27 energy system and mapping of local conditions, which is essential for district heating analysis. However, the link between these two actions has not been fully utilised in this pre-study due to the limited working time available: The mapping action has only indicated the input to the energy modelling action.
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| 7. |
- Dalla Rosa, Alessandro, et al.
(författare)
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Annex X Final report : Toward 4th Generation District Heating: Experience and Potential of Low-Temperature District Heating
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Background and ObjectiveThe evolution of district heating (DH) has gone through three generations since the first introduction of distirct heating. It is characterized by the type of transport media and the network temperature levels: the 1st generation DH system is steam-based system, the 2nd generation DH uses high network supply temperature above 100oC, and the 3rd generation DH represents the current DH system with medium network supply temperature between 80oC to 100oC. Up until now, the 4th generation DH as the low-temperature district heating (LTDH) is emerging as a new system which is going to replace the existing 3rd generation DH system. Comparing with the existing DH system, the LTDH reduces the network supply temperature down to consumer required temperature level, thus greatly improves the quality match between the energy supply and the energy demand. Meanwhile, LTDH coupling with reduced network temperature and well-designed DH network can reduce network heat loss by up to 75% comparing with the current system. This makes DH economically competitive comparing with local heat generation units in the areas with low heat density or with low-energy buildings.The traditional approach to evaluating a DH system often focuses on the production/supply aspect and only afterwards on the final users. The LTDH concept switches the perspective, starting from end-user thermal comfort and a quality match between energy supply and energy consumption, and aiming to find the best and most economical way to satisfy the heat demand through efficient distribution networks and supply systems based on waste heat and RE. The new concept therefore starts by identifying suitable in-house substations for low-energy-demand buildings at low supply temperature, goes back to design efficient and reliable networks, and finally considers environmentally-friendly heat production units.This report describes the concept of LTDH, collects and discusses successful examples of implementation LTDH in the building heating sector. The objective of this report is to raise awareness and provide insights that will stimulate the research, development and implementation of LTDH systems. It will help to increase public recognition and assist policy makers and energy planners, both at local and governmental level, in promoting cost-effective and environmentally friendly DH systems, and in planning and realizing long-term sustainable urban area development. To this end, the report addresses the following research issues:1. What are the main advantages of LTDH?2. What technology options are available for LTDH, and what are the associated challenges to consider?3. How can the risk of Legionella be mitigated in LTDH?4. What lessons can be learned from early LTDH projects?5. What heat distribution costs are associated with LTDH?
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| 8. |
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| 9. |
- Gadd, Henrik, 1967-, et al.
(författare)
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Achieving low return temperature from district heating substations
- 2014
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Ingår i: Applied Energy. - Kidlington : Pergamon Press. - 0306-2619 .- 1872-9118. ; 136, s. 59-67
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Tidskriftsartikel (refereegranskat)abstract
- District heating systems contribute with low primary energy supply in the energy system by providing heat from heat assets like combined heat and power, waste incineration, geothermal heat, wood waste, and industrial excess heat. These heat assets would otherwise be wasted or not used. Still, there are several reasons to use these assets as efficiently as possible, i.e., ability to compete, further reduced use of primary energy resources, and less environmental impact. Low supply and return temperatures in the distribution networks are important operational factors for obtaining an efficient district heating system. In order to achieve low return temperatures, customer substations and secondary heating systems must perform without temperature faults. In future fourth generation district heating systems, lower distribution temperatures will be required. To be able to have well-performing substations and customer secondary systems, continuous commissioning will be necessary to be able to detect temperature faults without any delays. It is also of great importance to be able to have quality control of eliminated faults. Automatic meter reading systems, recently introduced into district heating systems, have paved the way for developing new methods to be used in continuous commissioning of substations. This paper presents a novel method using the temperature difference signature for temperature difference fault detection and quality assurance of eliminated faults. Annual hourly datasets from 140 substations have been analysed for temperature difference faults. From these 140 substations, 14 were identified with temperature difference appearing or eliminated during the analysed year. Nine appeared during the year, indicating an annual temperature difference fault frequency of more than 6%. © 2014 The Authors.
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| 10. |
- Gadd, Henrik, 1967-, et al.
(författare)
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Daily heat load variations in Swedish district heating systems
- 2013
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Ingår i: Applied Energy. - Oxford : Pergamon Press. - 0306-2619 .- 1872-9118. ; 106, s. 47-55
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Tidskriftsartikel (refereegranskat)abstract
- Heat load variations in district heating systems are both seasonal and daily. Seasonal variations have mainly its origin from variations in outdoor temperature over the year. The origin of daily variations is mainly induced by social patterns due to customer social behaviours. Heat load variations cause increased costs because of increased peak heat load capacity and expensive peak fuels. Seasonal heat load variations are well-documented and analysed, but analyses of daily heat load variations are scarce. Published analyses are either case studies or models that try to predict daily heat load variations. There is a dearth of suitable assessment methods for more general analyses of existing daily load variations. In this paper, a novel assessment method for describing daily variations is presented. It is applied on district heating systems, but the method is generic and can be applied on every kind of activity where daily variations occur. The method was developed from two basic conditions: independent of system size and no use of external parameters other than of the time series analysed. The method consists of three parameters: the annual relative daily variation that is a benchmarking parameter between systems, the relative daily variation that describes the expected heat storage size to eliminate daily variations, and the relative hourly variation that describes the loading and unloading capacity to and from the heat storage. The assessment method could be used either for design purposes or for evaluation of existing storage. The method has been applied on 20 Swedish district heating systems ranging from small to large systems. The three parameters have been estimated for time series of hourly average heat loads for calendar years. The results show that the hourly heat load additions beyond the daily averages, vary between 3% and 6% of the annual volume of heat supplied to the network. Hereby, the daily variations are smaller than the seasonal variations, since the daily heat load additions, beyond the annual average heat load, are between 17% and 28% of the annual volume of heat supplied to the network. The size of short term heat storage to eliminate the daily heat load variations has been estimated to a heat volume corresponding to about 17% of the average daily heat supplied into the network. This conclusion can also be expressed as an average demand of 2.5 m3 of heat storage volume per TJ of heat supplied by assuming a water temperature difference of 40 C. The capacity for loading and unloading the storage should be equal to about half of the annual average heat load for heat supplied into the network. © 2013 Elsevier Ltd.
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