hig.sePublikationer
Ändra sökning
Avgränsa sökresultatet
1 - 22 av 22
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Amiri, Shahnaz
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energiteknik.
    Moshfegh, Bahram
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energiteknik.
    Possibilities and consequences of deregulation of the European electricity market for connection of heat sparse areas to district heating systems2010Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, nr 7, s. 2401-2410Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objective of the study is to analyse the conditions for connection of residential buildings in heat sparse areas to district heating systems in order to increase electricity production in municipal combined heat and power plants. The European electricity market has been assumed to be fully deregulated. The relation between connection of heat sparse areas, increased electricity and heat production as well as electricity prices, fuel prices and emissions rights is investigated. The results of the study show that there is potential to expand the district heating market to areas with lower heat concentrations in the cities of Gavle, Sandviken and Borlange in Sweden, with both economic and environmental benefits. The expansion provides a substantial heat demand of approximately 181 GWh/year, which results in an electricity power production of approximately 43 GWh/year. Since the detached and stand-alone houses in the studied heat sparse areas have been heated either by oil boiler or by direct electricity, connection to district heating also provides a substantial reduction in emissions of CO(2). The largest reductions in CO(2) emissions are found to be 211 ktonnes/year assuming coal-fired condensing power as marginal electricity production. Connection of heat sparse areas to district heating decrease the system costs and provide a profitability by approximately 22 million EURO/year for the studied municipalities if the price of electricity is at a European level, i.e. 110 EURO/MWh. Sensitivity analysis shows, among other things, that a strong relation exists between the price of electricity and the profitability of connecting heat sparse areas to district heating systems.

  • 2.
    Aslani, Mohammad
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för datavetenskap och samhällsbyggnad, Datavetenskap.
    Seipel, Stefan
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för datavetenskap och samhällsbyggnad, Datavetenskap. Uppsala universitet.
    Automatic identification of utilizable rooftop areas in digital surface models for photovoltaics potential assessment2022Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 306, artikel-id 118033Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The considerable potential of rooftop photovoltaics (RPVs) for alleviating the high energy demand of cities has made them a proven technology in local energy networks. Identification of rooftop areas suitable for installing RPVs is of importance for energy planning. Having these suitable areas referred to as utilizable areas greatly assists in a reliable estimate of RPVs energy production. Within such a context, this research aims to propose a spatially detailed methodology that involves (a) automatic extraction of buildings footprint, (b) automatic segmentation of roof faces, and (c) automatic identification of utilizable areas of roof faces for solar infrastructure installation. Specifically, the innovations of this work are a new method for roof face segmentation and a new method for the identification of utilizable rooftop areas. The proposed methodology only requires digital surface models (DSMs) as input, and it is independent of other auxiliary spatial data to become more functional. A part of downtown Gothenburg composed of vegetation and high-rise buildings with complex shapes was selected to demonstrate the methodology performance. According to the experimental results, the proposed methodology has a high success rate in building extraction (about 95% correctness and completeness) and roof face segmentation (about 85% completeness and correctness). Additionally, the results suggest that the effects of roof occlusions and roof superstructures are satisfactorily considered in the identification of utilizable rooftop areas. Thus, the methodology is practically effective and relevant for the detailed RPVs assessments in arbitrary urban regions where only DSMs are accessible.

    Ladda ner fulltext (pdf)
    fulltext
  • 3.
    Cabral, Diogo
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Development and performance comparison of a modified glazed CPC hybrid solar collector coupled with a bifacial PVT receiver2022Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 325, artikel-id 119653Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Innovative concentrating PVT solar collector concepts based on a CPC geometry concept were developed to outperform the asymmetric Solarus CPVT collector and therefore decrease the energy/performance gap between CPVT and PV/ST solar collectors. The updated reflector geometry proved to be the most suitable reflector geometry for CPVTs, where the electrical peak efficiency per gross area reached 10.6%, which is +16.5%rel higher than the electrical peak efficiency of the Solarus CPVT. Optical efficiencies of η0 = 62.3% and η0 = 61.8% for CPC 1 and CPC 2 have been achieved, respectively. A PV module (0.5 m2) combined with an ST solar collector (0.5 m2) system to be able to deliver the same overall energy yield as the newly developed CPVT collector (1 m2) requires on average +0.02 m2 (at 45 °C), −0.06 m2 (at 55 °C) and −0.15 m2 (at 65 °C) of installed area, for a wide range of latitudes. A CPC-PVT system to increase its competitiveness requires a material cost reduction and at the same time an increased overall efficiency. Nevertheless, the energy/performance gap between a system composed of PV + ST technologies and a CPC-PVT decreased significantly.

    Ladda ner fulltext (pdf)
    fulltext
  • 4.
    Daianova, Lilia
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Evaluation of a regional bioenergy system with local production of biofuel for transportation, integrated with a CHP plant2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 92, s. 739-749Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The share of renewable liquid fuels (ethanol, fatty acid methyl ester, biogas, and renewable electricity) in the total transportation fuel in Sweden, has increased by the end of 2009 to such level that e.g. domestic bioethanol production is unable to satisfy current ethanol fuel demand. Regional small-scale ethanol production can assist the region in covering the regional needs in transport fuel supply.

    Current case study system includes the production of ethanol, biogas, heat and power from locally available cereals straw. A mixed integer programming (MIP) model is developed for cost optimization of regional transport fuel supply (ethanol, biogas and petrol). The model is applied for two cases, one when ethanol production plant is integrated with an existing CHP plant (polygeneration), and one with a standalone ethanol production plant.

    The optimization results show that for both cases the changes in ethanol production costs have the biggest influence on the costs for supplying regional passenger car fleet with transport fuel. Petrol fuel price and straw production costs have also a significant effect on costs for supplying cars with transport fuel for both standalone ethanol production and integrated production system.

    By integrating the ethanol production process with a CHP plant, the costs for supplying regional passenger car fleet with transport fuel can be cut by 31%, from 150 to 104 €/MW h fuel, which should be compared with E5 costs of 115 €/MW h (excl VAT).

  • 5.
    Daraei, Mahsa
    et al.
    Mälardalens högskola, Framtidens energi.
    Avelin, Anders
    Mälardalens högskola, Framtidens energi.
    Dotzauer, Erik
    Mälardalens högskola, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Framtidens energi.
    Evaluation of biofuel production integrated with existing CHP plants and the impacts on production planning of the system – A case study2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 252, artikel-id 113461Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The increasing atmospheric CO2 concentration has caused a transformative shift in global energy systems, which is contributing to an increased use of renewables. Sweden is among the countries trying to shift to a fossil-fuel-free system in all energy sectors. This paper addresses the fuel demand and supply in the transportation sector in the county of Västmanland in Sweden. A Mixed Integer Linear Programming optimization model is developed to minimize cost in the studied system. The model is further used to investigate the influence of three different scenarios on production planning of regional Combined Heat and Power (CHP) plants: (1) straw-based biofuel production integrated with existing CHP plants to fuel combustion engine vehicles, (2) use of electric vehicles, and (3) use of hybrid vehicles fueled by both electricity and bioethanol. Potential solar power generation from rooftop solar cells is also included in the model. The energy system in scenario 2 is found to have the highest overall system efficiency; however, a large amount of power needs to be imported to the system. Hybrid vehicles can potentially reduce the electricity import and CO2 emissions compared to the current situation. Electricity production from rooftop solar collectors could provide the energy needs of the vehicles during summer, while regionally produced straw-based bioethanol integrated with CHP plants can satisfy the fuel needs of the vehicles in winter. This approach could affect the production planning of CHP plants, result in less fuel use and increase the share of renewable resources in the regional transportation system. 

  • 6.
    Djuric Ilic, Danica
    et al.
    Linköpings universitet, Energisystem.
    Dotzauer, Erik
    School of Sustainable Development of Society and Technology, Mälardalen University, Västerås, Sweden.
    Trygg, Louise
    Linköpings universitet, Energisystem.
    District heating and ethanol production through polygeneration in Stockholm2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 91, nr 1, s. 214-221Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethanol can be produced with little impact on the environment through the use of polygeneration technology. This paper evaluates the potential of integrating a lignocellulosic ethanol plant into a district heating system by case study; the plant has an ethanol capacity of 95 MW with biogas. electricity and heat as by-products. Stockholms district heating system is used as the case study, but the results may be relevant also for other urban areas. The system has been studied using MODEST - an optimisation model framework. The results show that introducing the plant would lead to a significant reduction in the cost of heat production. The income from the biofuels and electricity produced would be about (sic)76 million and (sic)130 million annually, respectively, which is an increase of 70% compared to the income from the electricity produced in the system today. Assuming that the electricity produced will replace marginal electricity on the European electricity market and that the biofuel produced will replace gasoline in the transport sector, the introduction of the polygeneration plant in the district heating system would lead to a reduction of global CO(2) emissions of about 0.7 million tonnes annually.

  • 7.
    Joudi, Ali
    et al.
    Energy and Environmental Technology, Dalarna University, Falun, Sweden .
    Cehlin, Mathias
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energiteknik.
    Rönnelid, Mats
    Energy and Environmental Technology, Dalarna University, Falun, Sweden .
    Reflective coatings for interior and exterior of buildings and improving thermal performance2013Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 103, s. 562-570Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The importance of reducing building energy usage and thriving for more energy efficient architectures, has nurtured creative solutions and smart choices of materials in the last few decades. Among those are optimizing surface optical properties for both interior and exterior claddings of the building. Development in the coil-coating steel industries has now made it possible to allocate correct optical properties for steel clad buildings with improved thermal performance. Although the importance of the exterior coating and solar gain are thoroughly studied in many literatures, the effect of interior cladding are less tackled, especially when considering a combination of both interior and exterior reflective coatings. This paper contemplates the thermal behavior of small cabins with reflective coatings on both interior and exterior cladding, under different conditions and climates with the aim to clarify and point out to the potential energy saving by smart choices of clad coatings.

  • 8.
    Karlsson, Magnus
    et al.
    Department of Management and Engineering, Division of Energy Systems, Linköping University, Sweden.
    Gebremedhin, Alemayehu
    Department of Management and Engineering, Division of Energy Systems, Linköping University, Sweden.
    Klugman, Sofia
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för energi- och maskinteknik.
    Henning, Dag
    Optensys Energianalys, Linköping, Sweden.
    Moshfegh, Bahram
    Department of Management and Engineering, Division of Energy Systems, Linköping University, Sweden.
    Regional energy system optimization - Potential for a regional heat market2009Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, nr 4, s. 441-451Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Energy supply companies and industrial plants are likely to face new situations due to, for example, the introduction of new energy legislation, increased fuel prices and increased environmental awareness. These new prerequisites provide companies with new challenges but also new possibilities from which to benefit. Increased energy efficiency within companies and increased cooperation between different operators are two alternatives to meet the new conditions. A region characterized by a high density of energy-intensive processes is used in this study to find the economic potential of connecting three industrial plants and four energy companies, within three local district heating systems, to a regional heat market, in which different operators provide heat to a joint district heating grid. Also, different investment alternatives are studied. The results show that the economical potential for a heat market amounts to between 5 and 26 million EUR/year with payback times ranging from two to eleven years. However, the investment costs and the net benefit for the total system need to be allotted to the different operators, as they benefit economically to different extents from the introduction of a heat market. It is also shown that the emissions of CO(2) from the joint system would decrease compared to separate operation of the systems. However, the valuation of CO(2) emissions from electricity production is important as the difference of emitted CO(2) between the accounting methods exceeds 650 kton/year for some scenarios. (C) 2008 Elsevier Ltd. All rights reserved.

  • 9.
    Klugman, Sofia
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för energi- och maskinteknik.
    Karlsson, Magnus
    Department of Mechanical Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    Department of Mechanical Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    A Scandinavian chemical wood-pulp mill: Part 1. Energy audit aiming at efficiency measures2007Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 84, nr 3, s. 326-339Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A Swedish wood-pulp mill is surveyed in terms of energy supply and use in order to determine the energy-saving potential. Conservation measures are of increasing interest to Swedish industry, as energy prices have continued to rise in recent years. The electricity price particularly increased after the deregulation of the Scandinavian electricity market in 1996. The deregulation expanded to all of the EU in July 2004, which may increase the Swedish electricity price further until it reaches the generally higher European price level. Furthermore, oil prices have increased and the emissions trading scheme for CO2 adds to the incentive to reduce oil consumption. The energy system at the surveyed pulp mill is described in terms of electricity and process heat production and use. The total energy-saving potential is estimated and some saving points are identified. The heat that today is wasted at the mill has been surveyed in order to find potential for heat integration or heat export. The result shows that the mill probably could become self-sufficient in electricity. Particularly important in that endeavor is updating old pumps.

  • 10.
    Klugman, Sofia
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för energi- och maskinteknik.
    Karlsson, Magnus
    Department of Mechanical Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    Department of Mechanical Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    A Scandinavian chemical wood-pulp mill: Part 2. International and model mills comparison2007Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 84, nr 3, s. 340-350Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The energy use at a Swedish chemical wood-pulp mill is compared internationally and for two model mills that aim to use the most efficient available technology. The international comparison is performed between Canadian and Scandinavian pulp-mills on a general level, and on a closer level among eleven Swedish and Finnish non-integrated sulfate pulp-mills, the type of mill considered in the case study. The two model mills that are used for comparison are one Swedish and one Canadian. The Scandinavian pulp-mills are somewhat more energy efficient than the Canadian mills. Still, the variation in energy use is remarkably large among the Scandinavian mills, which indicates that the energy-saving potential is great. If all Swedish freestanding sulfate pulp-mills became as energy efficient as the most efficient Scandinavian mill, electricity savings corresponding to nearly 1% of the national electricity use would be obtained. In the model mills comparison it was found that large amounts of heat could be saved, particularly in the evaporation plant.

  • 11.
    Leduc, S.
    et al.
    International Institute for Applied System Analysis (IIASA), A-2361 Laxenburg, Austria;b.Division of Energy Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden.
    Lundgren, J.
    International Institute for Applied System Analysis (IIASA), A-2361 Laxenburg, Austria;b.Division of Energy Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden.
    Franklin, O.
    International Institute for Applied System Analysis (IIASA), A-2361 Laxenburg, Austria.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Location of a biomass based methanol production plant: A dynamic problem in northern Sweden2010Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, nr 1, s. 68-75Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Concerning production and use of biofuels, mismatch between the locations of feedstock and the biofuel consumer may lead to high transportation costs and negative environmental impact. In order to minimize these consequences, it is important to locate the production plant at an appropriate location. In this paper, a case study of the county of Norrbotten in northern Sweden is presented with the purpose to illustrate how an optimization model could be used to assess a proper location for a biomass based methanol production plant. The production of lignocellulosic based methanol via gasification has been chosen, as methanol seems to be one promising alternative to replace fossil gasoline as an automotive fuel and Norrbotten has abundant resources of woody biomass. If methanol would be produced in a stand-alone production plant in the county, the cost for transportation of the feedstock as well as the produced methanol would have great impact on the final cost depending on where the methanol plant is located. Three different production plant sizes have been considered in the study, 100, 200 and 400 MW (biomass fuel input), respectively. When assessing a proper location for this kind of plant, it is important to also consider the future motor fuel demand as well as to identify a heat sink for the residual heat. In this study, four different automotive fuel- and district heating demand scenarios have been created until the year 2025. The results show that methanol can be produced at a maximum cost of 0.48 €/l without heat sales. By selling the residual heat as district heating, the methanol production cost per liter fuel may decrease by up to 10% when the plant is located close to an area with high annual heat demand.

  • 12.
    Leduc, Sylvain
    et al.
    Luleå tekniska universitet, Energivetenskap.
    Natarajan, Karthikeyan
    International Institute for Applied System Analysis (IIASA), A-2361 Laxenburg, Austria.
    Dotzauer, Erik
    Mälardalen University, Sweden.
    McCallum, Ian
    International Institute for Applied System Analysis (IIASA), A-2361 Laxenburg, Austria.
    Obersteiner, Michael
    International Institute for Applied System Analysis (IIASA), A-2361 Laxenburg, Austria.
    Optimizing biodiesel production in India2009Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, nr Suppl. 1, s. S125-S131Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    India is expected to at least double its fuel consumption in the transportation sector by 2030. To contribute to the fuel supply, renewable energies such as jatropha appear to be an attractive resource for biodiesel production in India as it can be grown on waste land and does not need intensive water supply. In order to produce biodiesel at a competitive cost, the biodiesel supply chain - from biomass harvesting to biodiesel delivery to the consumers - is analyzed. A mixed integer linear programming model is used in order to determine the optimal number and geographic locations of biodiesel plants. The optimization is based on minimization of the costs of the supply chain with respect to the biomass, production and transportation costs. Three biodiesel blends are considered, B2, B5 and B10. For each blend, 13 scenarios are considered where yield, biomass cost, cake price, glycerol price, transport cost and investment costs are studied. A sensitivity analysis is carried out on both those parameters and the resulting locations of the plants. The emissions of the supply chain are also considered. The results state that the biomass cost has most influence on the biodiesel cost (an increase of feedstock cost increases the biodiesel cost by about 40%) and to a lower effect, the investment cost and the glycerol price. Moreover, choosing the right set of production plant locations highly depends on the scenarios that have the highest probability to occur, for which the production plant locations still produce a competitive biodiesel cost and emissions from the transportation are minimum. In this study, one set of plant locations happened to meet these two requirements.

  • 13.
    Lidberg, Tina
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem. Högskolan Dalarna.
    Gustafsson, Marcus
    Högskolan Dalarna; KTH.
    Myhren, Jonn Are
    Högskolan Dalarna.
    Olofsson, Thomas
    Högskolan Dalarna; Umeå universitet.
    Ödlund, L.
    Linköpings universitet.
    Environmental impact of energy refurbishment of buildings within different district heating systems2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 227, s. 231-238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    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.

  • 14.
    Monie, Svante
    et al.
    Uppsala universitet, Byggteknik och byggd miljö.
    Åberg, Magnus
    Uppsala universitet, Byggteknik och byggd miljö.
    Potential to balance load variability, induced by renewable power, using rock cavern thermal energy storage, heat pumps, and combined heat and power in Sweden2023Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 343, artikel-id 121210Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 15.
    Patrizio, P.
    et al.
    University of Udine, Udine, Italy.
    Leduc, S.
    International Institute for Applied Systems Analysis, Laxenburg, Austria.
    Chinese, D.
    University of Udine, Udine, Italy.
    Dotzauer, Erik
    Mälardalens högskola, Framtidens energi.
    Kraxner, F.
    International Institute for Applied Systems Analysis, Laxenburg, Austria.
    Biomethane as transport fuel - A comparison with other biogas utilization pathways in northern Italy2015Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 157, s. 25-34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Italy is a large producer of biogas from anaerobic digestion, which is mainly used for power generation with limited use of cogenerated heat. Other utilization pathways, such as biomethane injection into the natural gas grid or biomethane used as a vehicle fuel, remain unexplored. Given the dense grid of natural gas pipelines and existing Compressed Natural Gas (CNG) refueling stations in northern Italy, significant market opportunities for biogas could also arise in the heating and transport sectors. The main objectives of this paper are to explore the potential role of agricultural biogas in different utilization pathways. Biogas combustion for simultaneous production of heat and power in small Combined Heat and Power (CHP) facilities is also assessed, as is upgrading to biomethane for transport or natural gas grid injection in the specific context of northern Italy. The spatially explicit optimization model BeWhere is used to identify optimal locations where greenfield biogas plants could be installed and to determine the most economic and environmentally beneficial mix of conversion technologies and plant capacities. Carbon price, for instance in the form of tradable emission permits, is assessed as a policy instrument and compared with other options such as price premiums on biomethane or electricity costs. Results show that starting from a carbon price of 15EUR/tCO<inf>2</inf>, the cogeneration option is preferable if plants are located in the proximity of existing district heating infrastructure. CNG plants are only competitive starting at a carbon price of 70EUR/tCO<inf>2</inf> in areas with high feedstock availability. The sensitivity analysis for energy prices reveals that a larger number of CNG facilities are included in the optimal mix at higher gas wholesale prices. This further indicates that specific premiums are needed to expand the biomethane market share, while greenhouse gas emission reductions would primarily be achieved by fostering cogeneration of electricity and heat supported by carbon price-based policy instruments.

  • 16.
    Petrovic, Bojana
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik. Department of Energy and Construction Technology, Dalarna University, Falun, Sweden.
    Myhren, Jonn Are
    Department of Energy and Construction Technology, Dalarna University, Falun, Sweden.
    Zhang, Xingxing
    Department of Energy and Construction Technology, Dalarna University, Falun, Sweden.
    Wallhagen, Marita
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Miljövetenskap.
    Eriksson, Ola
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Miljövetenskap.
    Life cycle assessment of a wooden single-family house in Sweden2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 251, s. 1456-1465, artikel-id 113253Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To understand the reasons behind the large environmental impact from  buildings the whole life cycle needs to be considered. Therefore, this study  evaluates the carbon dioxide emissions in all stages of a single-family house  in Sweden from the production of building materials, followed by construction  and user stages until the end-of-life of the building in a life cycle  assessment (LCA). The methodology applied is attributional life cycle  assessment (LCA) based on `One Click LCA' tool and a calculated life span of  100 years. Global warming potential (GWP) and primary energy (PE) are  calculated by using specific data from the case study, furthermore the data  regarding building materials are based on Environmental Product Declarations  (EPDs). The results show that the selection of wood-based materials has a  significantly lower impact on the carbon dioxide emissions in comparison with  non-wood based materials. The total emissions for this single-family house in  Sweden are 6 kg CO2e/m2/year. The production stage of building materials,  including building systems and installations represent 30% of the total  carbon dioxide equivalent emissions, while the maintenance and replacement  part represents 37%. However, energy use during the in-use stage of the house  recorded lower environmental impact (21%) due to the Swedish electricity mix  that is mostly based on energy sources with low carbon dioxide emissions. The  water consumption, construction and the end-of-life stages have shown minor  contribution to the buildings total greenhouse gas (GHG) emissions (12%). The  primary energy indicator shows the largest share in the operational phase of  the house. 

  • 17.
    Soam, Shveta
    et al.
    DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Faridabad, India.
    Kapoor, M.
    DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Faridabad, India.
    Kumar, R.
    DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Faridabad, India.
    Börjesson, P.
    Environmental and Energy Systems Studies, Lund University, Lund, Sweden.
    Gupta, R. P.
    DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Faridabad, India.
    Tuli, D. K.
    DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Faridabad, India.
    Global warming potential and energy analysis of second generation ethanol production from rice straw in India2016Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 184, s. 353-364Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The environmental sustainability of cellulosic ethanol production from rice straw in India is conducted using life cycle assessment (LCA). Greenhouse gas (GHG) emissions, net energy ratio (NER) and net energy balance (NEB) are studied for ethanol production system using two diverse pretreatment technologies, i.e. dilute acid (DA) and steam explosion (SE) followed by separate hydrolysis and fermentation. 1 ton of rice straw is the reference flow of study and 1 MJ transportation fuel is the functional unit while comparing the results with gasoline. The inventory data is collected based on several experiments conducted at our pilot plant and is a novel contribution to country specific LCA. Using DA and SE, the ethanol yields from the processing of 1 ton straw are 239 and 253 L and life cycle GHG emissions are 292 and 288 kg CO2 eq./ton straw respectively. The results indicated that production of enzyme used in hydrolysis is the major contributor to GHG emissions in both DA (54%) and SE (57%) methods of ethanol production. The net energy input during the life cycle of ethanol is 1736 and 1377 MJ/ton straw in DA and SE respectively. The major GHG emissions and energy benefits are obtained using lignin produced in the plant to generate electricity resulting in displacement of the coal based electricity. With a higher xylose recovery in the SE, it gives larger amount of ethanol and also generates more surplus electricity. Enzyme production and its use are identified as GHG emission and energy consumption hotspot in the ethanol production process. While comparing the results with gasoline, DA and SE resulted in a reduction of 77 and 89% GHG emissions and NER of 2.3 and 2.7 respectively. The E5 blending would reduce GHG emissions by 4.3% (DA) and 4.8% (SE) whereas; E20 blend would lead to a reduction of 17.4% (DA) and 18.8% (SE) respectively. Sensitivity analysis indicates that with every 12.5% increase in the price of rice straw from the base case, there is a 2.3% increase in GHG emissions and vice versa. 1 FPU/g WIS increase during hydrolysis gives 2.9% increase in ethanol production, but at the same time there is an increase of 5% emissions from enzyme production. The results of the study conclude that cellulosic ethanol production technology in India is sustainable from GHG reduction and energy efficiency perspective.

  • 18.
    Starfelt, Fredrik
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Daianova, Lilia
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    The impact of lignocellulosic ethanol yields in polygeneration with district heating: A case study2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 92, s. 791-799Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development towards high energy efficiency and low environmental impact from human interactions has led to changes at many levels of society. As a result of the introduction of penalties on carbon dioxide emissions and other economic instruments, the energy industry is striving to improve energy efficiency and climate mitigation by switching from fossil fuels to renewable fuels. Biomass-based combined heat and power (CHP) plants connected to district heating networks have a need to find uses for the excess heat they produce in summer when the heat demand is low. On the other hand, the transport sector makes a substantial contribution to the increasing CO 2 emissions, which have to be reduced. One promising alternative to address these challenging issues is the integration of vehicle fuel production with biomass-based CHP plants. This paper presents the configuration and operating profits in terms of electricity, heat and ethanol fuel from cellulosic biomass. A case study of a commercial small scale CHP plant was conducted using simulation and modeling tools. The results clearly show that electricity production can be increased when CHP production is integrated with cellulosic ethanol production. The findings also show that the economic benefits of the energy system can be realized with near-term commercially available technology, and that the benefits do not rely solely on ethanol yields.

  • 19.
    Stigson, Peter
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Jinhyue, Yan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Improving policy making through government-industry policy learning: the case of a novel Swedish policy framework2009Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, nr 4, s. 399-406Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Climate change poses an unprecedented challenge for policy makers. This paper analyzes how industry sector policy expertise can contribute to improved policy making processes. Previous research has identified that policy making benefit by including non-governmental policy analysts in learning processes. Recent climate and energy policy developments, including policy amendments and the introduction of new initiatives, have rendered current policy regimes as novel both to governments and the industry. This increases business investment risk perceptions and may thus reduce the effectiveness and efficiency of the policy framework. In order to explore how government-industry policy learning can improve policy making in this context, this article studied the Swedish case. A literature survey analyzed how policy learning had been previously addressed, indentifying that the current situation regarding novel policies had been overlooked. Interviews provided how industrial actors view Swedish policy implementation processes and participatory aspects thereof. The authors conclude that an increased involvement of the industry sector in policy design and management processes can be an important measure to improve the effectiveness and efficiency of climate and energy policies.

  • 20.
    Trygg, Louise
    et al.
    Linköpings universitet.
    Amiri, Shahnaz
    Linköpings universitet.
    European perspective on absorption cooling in a combined heat and power system – A case study of energy utility and industries in Sweden2007Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 84, nr 12, s. 1319-1337Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mankind is facing an escalating threat of global warming and there is increasing evidence that this is due to human activity and increased emissions of carbon dioxide. Converting from vapour compression chillers to absorption chillers in a combined heat and power (CHP) system is a measure towards sustainability as electricity consumption is replaced with electricity generation. This electricity produced in Swedish CHP-system will substitute marginally produced electricity and as result lower global emissions of carbon dioxide. The use of absorption chillers is limited in Sweden but the conditions are in fact most favourable. Rising demand of cooling and increasing electricity prices in combination with a surplus of heat during the summer in CHP system makes heat driven cooling extremely interesting in Sweden. In this paper we analyse the most cost-effective technology for cooling by comparing vapour compression chillers with heat driven absorption cooling for a local energy utility with a district cooling network and for industries in a Swedish municipality with CHP. Whilst this case is necessarily local in scope, the results have global relevance showing that when considering higher European electricity prices, and when natural gas is introduced, absorption cooling is the most cost-effective solution for both industries and for the energy supplier. This will result in a resource effective energy system with a possibility to reduce global emissions of CO2 with 80%, a 300% lower system cost, and a 170% reduction of the cost of producing cooling due to revenues from electricity production. The results also show that, with these prerequisites, a decrease in COP of the absorption chillers will not have a negative impact on the cost-effectiveness of the system, due to increased electricity production.

  • 21.
    Weinberger, Gottfried
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem.
    Amiri, Shahnaz
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    On the benefit of integration of a district heating system with industrial excess heat: an economic and environmental analysis2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 191, s. 454-468Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Energy-related cooperation using industrial excess heat (IEH) in district heating (DH) networks shows economic and environmental benefits. A rarely investigated approach is the energy cooperation which incorporates a jointly operated CHP plant also producing process steam for nearby industry. The present study aims to evaluate economic and environmental effects on the Hofors DH system with jointly operated CHP plant when the nearby steel mill extends the supply of recovered IEH. Various IEH supply opportunities with different capacities of hot water and steam were designed and compared with existing IEH utilization, plant heat and electricity production and DH system performance. The energy system model MODEST is used for cost-optimization. A parametric study is used to analyze influences of increasing IEH cost and fluctuating electricity prices. The results show advantages for the DH system to utilize IEH for deliveries of DH and process steam and the cogeneration of electricity. Economic and environmental benefits are decreased total system cost (-1.67 MEUR/a), less use of fuels and electricity, and reduced CO2 emissions with a maximal reachable amount of 28,200 ton/a when the use of biofuel is assumed as limited resource and the substituted marginal electricity production is based on coal condensing power plants. The results also show that industrial steam is a preferred heat supply source as long as the steam cost is below the alternative heat production cost, irrespective of the electricity price. While the cost-effective utilization of industrial hot water for DH is more sensitive and affected by a beneficial CHP production based on higher electricity price segments, it is also shown that utilization of continuously supplied industrial hot water is limited during seasons of low DH demand.

  • 22.
    Weinberger, Gottfried
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem.
    Moshfegh, Bahram
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem.
    Investigating influential techno-economic factors for combined heat and power production using optimization and metamodeling2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 232, s. 555-571Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper investigates the interaction of a wide range of electricity and fuel prices and technical factors of combined heat and power production in a district heating system. A linear programming-based optimization model with the objective to minimize system cost was used to study the energy systems in the cities of Gävle and Sandviken in Sweden. The comprehensive outcomes from optimization and parametric studies have been analyzed using a polynomial-based metamodel. System costs include variable costs for the production and revenues for sale of heat and electricity. The metamodel is used as an analytical and explanatory tool to interpret input-output relationships. Municipal district heating systems of Gävle and Sandviken in Sweden are studied as an interconnected regional system with improved and new combined heat and power plants. The results show that effects from electricity and fuel prices are important, but that variations in energy system cost may also be caused by many cross-factor interactions with technical factors. A comparative system performance analysis with defined cases and optimal factor setting shows a substantial increase in the electricity production, here by up to 650 GWh annually. The profitability of investing in a new plant depends highly on the considered investment risk and electricity and fuel market prices. CO2 emission savings by up to 466 kton annually can be accomplished if marginal electricity production from coal-condensing power plants is avoided and biofuel is released at the same time.

1 - 22 av 22
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf