lnu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Truong, Nguyen Le
Publications (10 of 30) Show all publications
Truong, N. L. & Gustavsson, L. (2019). Costs and primary energy use of heating new residential areas with district heat or electric heat pumps. In: Prof. J.Yana, Prof. H.Yang, Dr. H.Li, Dr. X.Chen (Ed.), Innovative Solutions for Energy Transitions: Proceedings of the 10th International Conference on Applied Energy (ICAE2018). Paper presented at 10th International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, China (pp. 2031-2038). Elsevier, 158
Open this publication in new window or tab >>Costs and primary energy use of heating new residential areas with district heat or electric heat pumps
2019 (English)In: Innovative Solutions for Energy Transitions: Proceedings of the 10th International Conference on Applied Energy (ICAE2018) / [ed] Prof. J.Yana, Prof. H.Yang, Dr. H.Li, Dr. X.Chen, Elsevier, 2019, Vol. 158, p. 2031-2038Conference paper, Published paper (Refereed)
Abstract [en]

The choice of a heat supply option in new residential areas depends on various factors including available local energy resources and the scale and density of the heat demand in the areas. Here, we study costs and primary energy use of using district heat (DH) and ground-source electric heat pump (EHP) for heating a residential area being developed. We consider different architecture layouts and exploitations of the area along with different building energy efficiency standards which give different heat demand densities and profiles for this residential area. The analysis shows that for existing fuel-based energy supply systems, using DH is more primary energy efficient than using EHP to supply heat to the new residential area. However, if the future production of marginal electricity is based on state-of-the art technologies utilizing renewable energy resources, using EHP can be more primary energy efficient than using DH. The initial investment costs are much lower for options using DH than for options using ground-source EHP for the different exploitation alternatives. Also, the marginal heat cost for suppling DH to the residential area, excluding the sunk capital costs, is significantly lower than the heat cost for supplying heat with ground-source EHPs. The potential use of local ground-source heat linked to the exploitation level of residential area and energy performance of the buildings should be further analyzed in comparison to the use of other types of heat sources such as ambient air or ventilation air.

Place, publisher, year, edition, pages
Elsevier, 2019
Series
Energy Procedia, E-ISSN 1876-6102
Keywords
District heat; electrict heat pump; heat density; primary energy use; distribution heat loss
National Category
Energy Systems
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-81669 (URN)10.1016/j.egypro.2019.01.469 (DOI)000471031702060 ()2-s2.0-85063904515 (Scopus ID)
Conference
10th International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, China
Available from: 2019-04-04 Created: 2019-04-04 Last updated: 2019-08-29Bibliographically approved
Truong, N. L., Dodoo, A. & Gustavsson, L. (2019). Final and primary energy use for heating new residential area with varied exploitation levels, building energy performance and district heat temperatures. In: Jinyue Yan, Hong-xing Yang, Hailong Li, Xi Chen (Ed.), Innovative Solutions for Energy Transitions: . Paper presented at 10th International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, China (pp. 6544-6550). Elsevier, 158
Open this publication in new window or tab >>Final and primary energy use for heating new residential area with varied exploitation levels, building energy performance and district heat temperatures
2019 (English)In: Innovative Solutions for Energy Transitions / [ed] Jinyue Yan, Hong-xing Yang, Hailong Li, Xi Chen, Elsevier, 2019, Vol. 158, p. 6544-6550Conference paper, Published paper (Refereed)
Abstract [en]

There is great potential to build new energy-efficient building blocks in combination with efficient energy supply systems. Such a development will contribute to achieve national energy and climate goals as well as the overall aim for a sustainable development. Here, we analyze final and primary energy use for heating a new residential area by using district-heating. The area, located in Växjö, in south Sweden has potentially varied land exploitation levels, energy performance of buildings and district heat supply/return temperatures. The results show that the district heating demand will be reduced by about 52-56% if buildings in the area meet the Swedish passive house criteria instead of the Swedish building code. The exploitation levels of construction in the area strongly influence the total heating demands. A dense instead of a low exploitation will increase the area’s heating demand more than four times. But, the heat demand density of the residential area has quite a small impact on the total heat losses of the distribution network in contrast to changed supply and return temperatures. The distribution heat losses could be reduced by up to 50% with lower supply/return temperatures. However, a reduction of district heat supply/return temperatures to 50/20oC increases electricity use for boosting hot water temperature to avoid the risk of legionella bacteria. This causes a shift from district heat production to electricity production and increases the primary energy use. The results of this study can be used for further considerations of costs and benefits of energy supply options for new residential areas.

Place, publisher, year, edition, pages
Elsevier, 2019
Series
Energy Procedia, E-ISSN 1876-6102
National Category
Energy Systems
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-81667 (URN)10.1016/j.egypro.2019.01.103 (DOI)000471031706139 ()2-s2.0-85063884911 (Scopus ID)
Conference
10th International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, China
Available from: 2019-04-04 Created: 2019-04-04 Last updated: 2019-08-29Bibliographically approved
Truong, N. L., Dodoo, A. & Gustavsson, L. (2018). Effects of energy efficiency measures in district-heated buildings on energy supply. Energy, 142, 1114-1127
Open this publication in new window or tab >>Effects of energy efficiency measures in district-heated buildings on energy supply
2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 142, p. 1114-1127Article in journal (Refereed) Published
Abstract [en]

In this study we estimate the final and primary energy savings for different energy efficiency measures in a multi-apartment building when heated by small-, medium- or large-scale district-heat production systems (DHSs). The small-scale system is based on heat-only boilers, whereas the other two also include cogeneration of district heat and electricity. In the systems with cogeneration units, a change in building's heat demand may influence cogenerated electricity and hence the overall power system. For the building analyzed, the estimated annual total final heat and electricity savings were 136 (54%) and 30 MWh (52%), respectively, giving total annual primary energy savings of 177–289 MWh. This varies as the ratio of primary and final heat savings depends on the type of energy efficiency measure and the energy supply. For the same heat savings measure, a system with a heat-only boiler gave the highest primary energy savings, whereas a system based mostly on cogeneration of district heat and electricity in combination with averaged-efficiency standalone power plants gave the lowest primary energy savings. When the energy supply is based on energy-efficient renewable-based system, the differences in primary energy savings between large- and small-scale DHSs are minor for the same energy efficiency measure.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Energy efficiency; District-heated building; Primary energy use; District heat; Renewable energy system
National Category
Energy Systems
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-69549 (URN)10.1016/j.energy.2017.10.071 (DOI)000424854900094 ()2-s2.0-85038238788 (Scopus ID)
Available from: 2018-01-03 Created: 2018-01-03 Last updated: 2019-08-29Bibliographically approved
Dodoo, A., Gustavsson, L. & Truong, N. L. (2018). Primary energy benefits of cost-effective energy renovation of a district heated multi-family building under different energy supply systems. Energy, 143, 69-90
Open this publication in new window or tab >>Primary energy benefits of cost-effective energy renovation of a district heated multi-family building under different energy supply systems
2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 143, p. 69-90Article in journal (Refereed) Published
Abstract [en]

The European Union's Directive on energy performance of buildings emphasizes the need to take cost-effectiveness into account when measures are implemented for improved building energy efficiency. In this study, we investigate cost-effective energy renovation measures for a district heated building under different contexts, including varied locations, energy supply systems and economic scenarios. We determine the final and primary energy savings of cost-effective energy renovation packages for the building in the different contexts. The measures analysed include: improved insulation for attic floor, basement walls, and exterior walls; improved windows and doors; resource-efficient taps; heat recovery of exhaust ventilation air; energy-efficient household appliances and lighting. We consider three existing Swedish energy supply systems of varying district heat production scale and tariffs, and also plausible renewable-based energy supply systems. Our analysis calculates the final energy savings of the measures including the cost-effective renovation packages on hourly basis and links these to the different energy supply systems. The cost-effectiveness analysis is based on a double-stage optimization method, considering total and marginal investment costs of renovation measures as well as associated net present values of total and marginal cost savings. The results show that significant final and primary energy savings can be achieved when energy renovation measures are implemented for the building in the different contexts. This study shows that heat demand in existing Swedish building could be about halved while electricity use may be reduced considerably with cost-effective energy renovation measures. The economic viability of the renovation measures is sensitive to the economic regimes especially discount rates and energy price increase.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Building Technologies
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
urn:nbn:se:lnu:diva-68615 (URN)10.1016/j.energy.2017.10.113 (DOI)000425565700007 ()2-s2.0-85032969090 (Scopus ID)
Available from: 2017-11-06 Created: 2017-11-06 Last updated: 2019-08-29Bibliographically approved
Gustavsson, L., Haus, S., Lundblad, M., Lundström, A., Ortiz, C. A., Sathre, R., . . . Wikberg, P.-E. (2017). Climate change effects of forestry and substitution of carbon-intensive materials and fossil fuels. Renewable & sustainable energy reviews, 67, 612-624
Open this publication in new window or tab >>Climate change effects of forestry and substitution of carbon-intensive materials and fossil fuels
Show others...
2017 (English)In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 67, p. 612-624Article in journal (Refereed) Published
Abstract [en]

We estimate the climate effects of directing forest management in Sweden towards increased carbon storage in forests with more land set-aside for protection, or towards increased forest production for the substitution of carbon-intensive materials and fossil fuels, relative to a reference case of current forest management. We develop various scenarios of forest management and biomass use to estimate the carbon balances of the forest systems, including ecological and technological components, and their impacts on the climate in terms of radiative forcing. The scenario with increased set-aside area and the current level of forest residue harvest resulted in lower cumulative carbon emissions compared to the reference case for the first 90 years, but then showed higher emissions as reduced forest harvest led to higher carbon emissions from energy and material systems. For the reference case of current forest management, increased harvest of forest residues gave increased climate benefits. The most climatically beneficial alternative, expressed as reduced cumulative radiative forcing, in both the short and long terms is a strategy aimed at high forest production, high residue recovery rate, and high efficiency utilization of harvested biomass. Active forest management with high harvest levels and efficient forest product utilization will provide more climate benefit, compared to reducing harvest and storing more carbon in the forest.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Biomass residues ; Forest management ; Climate change ; Radiative forcing
National Category
Forest Science
Research subject
Technology (byts ev till Engineering)
Identifiers
urn:nbn:se:lnu:diva-57660 (URN)10.1016/j.rser.2016.09.056 (DOI)000389088900046 ()2-s2.0-84988361277 (Scopus ID)
Available from: 2016-10-28 Created: 2016-10-28 Last updated: 2019-08-29Bibliographically approved
Truong, N. L. & Gustavsson, L. (2017). Climate effects of biomass use in integrated energysystems. In: ECEEE Summer Study proceedings 2017: . Paper presented at ECEEE 2017 Summer Study on energy efficiency. May 29-Jun 3, 2017, Hyères, France (pp. 911-920). European Council for an Energy Efficient Economy (ECEEE)
Open this publication in new window or tab >>Climate effects of biomass use in integrated energysystems
2017 (English)In: ECEEE Summer Study proceedings 2017, European Council for an Energy Efficient Economy (ECEEE), 2017, p. 911-920Conference paper, Published paper (Refereed)
Abstract [en]

Biomass is a key resource in a society based on renewable energy, but is a limited resource and the use of biomass in one sector will influence its availability for other sectors. The global energy system is heavily dependent on fossil fuels, and the climate impacts of CO2 occur regardless of the source of emissions. As a result, the climatic effects of biomass use in an energy system depend largely on which biomass feedstock and bioenergy pathway is being used, and what type of fossil fuel pathway is being replaced. In this study, we evaluate the CO2 emissions and climate effects of woody biomass and fossil fuel use. We analyse the potential production of electricity, heat or transport distance when using one kWh of woody biomass and fossil energy system designed to provide the same service to society as the most energy efficient bioenergy systems. The fuel cycle inputs are included in the analyses and are based on different state-of-the art as well as emerging technologies for energy conversion. We quantify the primary energy use and annual CO2 emission of different bioenergy and fossil alternatives. We then calculate the cumulative CO2 emission and climate effects in terms of cumulative radiative forcing for the fossil and bioenergy systems. The results show that primary energy use, CO2 emission, and cumulative radiative forcing vary strongly between the studied alternatives. The use of bioelectricity and electric vehicles instead of biomotor fuel-based vehicles gives about twice the transport distance per unit of consumed woody biomass. Integrated energy systems that supply a package of energy services including electricity, heat and transport distance reduce the primary energy use and increase the climate benefits of woody biomass. The replacement of coal for heat and electricity production by the here studied woody biomass gives large climate benefits immediately.

Place, publisher, year, edition, pages
European Council for an Energy Efficient Economy (ECEEE), 2017
Keywords
bio fuel, vehicles, climate change, electric vehicles, primary energy, integrated energy system, radiative forcing
National Category
Energy Systems Bioenergy
Identifiers
urn:nbn:se:lnu:diva-72205 (URN)978-91-983878-0-3 (ISBN)978-91-983878-1-0 (ISBN)
Conference
ECEEE 2017 Summer Study on energy efficiency. May 29-Jun 3, 2017, Hyères, France
Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-06Bibliographically approved
Sathre, R., Gustavsson, L. & Truong, N. L. (2017). Climate effects of electricity production fuelled by coal, forest slash and municipal solid waste with and without carbon capture. Energy, 122, 711-723
Open this publication in new window or tab >>Climate effects of electricity production fuelled by coal, forest slash and municipal solid waste with and without carbon capture
2017 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 122, p. 711-723Article in journal (Refereed) Published
Abstract [en]

We analyse the climate implications of producing electricity in large-scale conversion plants using coal, forest slash and municipal solid waste with and without carbon capture and storage (CCS). We calculate the primary energy, carbon dioxide (CO2) and methane (CH4) emission profiles, and the cumulative radiative forcing (CRF) of different systems that produce the same amount of electricity. We find that using slash or waste for electricity production instead of coal somewhat increases the instantaneous CO2 emission from the power plant, but avoids significant subsequent emissions from decaying slash in forests or waste in landfills. For slash used instead of coal, we find robust near- and long-term reductions in total emissions and CRF. Climate effects of using waste instead of coal are more ambiguous: CRF is reduced when CCS is used, but without CCS there is little or no climate benefits of using waste directly for energy, assuming that landfill gas is recovered and used for electricity production. The application of CCS requires more fuel, but strongly reduces the CO2 emissions. The use of slash or waste together with CCS results in negative net emissions and CRF, i.e. global cooling.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Forest residues; Landfill; Carbon capture and storage; Radiative forcing; Fuel substitution
National Category
Energy Systems Climate Research
Identifiers
urn:nbn:se:lnu:diva-61035 (URN)10.1016/j.energy.2017.01.076 (DOI)000399267100060 ()2-s2.0-85011891091 (Scopus ID)
Available from: 2017-03-01 Created: 2017-03-01 Last updated: 2019-09-06Bibliographically approved
Gustavsson, L. & Truong, N. L. (2016). Bioenergy pathways for cars: Effects on primary energy use, climate change and energy system integration. Paper presented at 10th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), Dubrovnik, CROATIA, 2015. Energy, 115(3), 1779-1789
Open this publication in new window or tab >>Bioenergy pathways for cars: Effects on primary energy use, climate change and energy system integration
2016 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 115, no 3, p. 1779-1789Article in journal (Refereed) Published
Abstract [en]

Different pathways and technologies can be used to convert woody biomass to transport services, but the biomass use and climate implications vary strongly between the alternatives. This study focuses on primary energy use and climate change effects of using bioenergy for transportation in the context of a renewable-based energy system. Integrated pathways to improve the energy efficiency of power and transportation sectors and integrated intermittent renewable energy are considered. The results show that the bioenergy pathway that produces biomotor fuels to replace fossil fuels leads to high primary energy use and instantaneous biogenic CO2 emission per km of driving distance, thus increasing global warming during the first 40e50 years, compared to fossil alternatives. The electric vehicle pathway using bioelectricity from combined heat and power plants leads to immediate global cooling and much greater climate benefits in the long run compared to biomotor fuels. Climate change effects of light-duty vehicles could be strongly reduced by changes in technology together with system integration that links the transport sector to the electricity and heating sectors. The use of biomass should be considered in the context of the overall integrated energy system, and in relation to the development of energy conversion technologies between different sectors.

Keywords
Forest residues; Primary energy; Fossil fuel substitution; Light-duty vehicles; Energy system integration
National Category
Bioenergy
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-57659 (URN)10.1016/j.energy.2016.04.018 (DOI)000389104300026 ()2-s2.0-84975109862 (Scopus ID)
Conference
10th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), Dubrovnik, CROATIA, 2015
Available from: 2016-10-28 Created: 2016-10-28 Last updated: 2017-05-18Bibliographically approved
Truong, N. L. (2016). Costs and primary energy use of energy supply options to buildings of different energy efficiency levels. In: 2016 ACEEE Summer Study on Energy Efficiency in Buildings: From Components to Systems, From Buildings to Communities. Paper presented at ACEEE Summer Study on Energy Efficiency in Buildings. August 21 - 26, 2016, California, USA. American Council for an Energy Efficient Economy
Open this publication in new window or tab >>Costs and primary energy use of energy supply options to buildings of different energy efficiency levels
2016 (English)In: 2016 ACEEE Summer Study on Energy Efficiency in Buildings: From Components to Systems, From Buildings to Communities, American Council for an Energy Efficient Economy, 2016Conference paper, Published paper (Refereed)
Abstract [en]

An appropriate energy solution for buildings depends on the scale of demand and the availability of the surrounding technical infrastructure. Building energy demand can be altered by the application of various energy efficiency measures whereas the performance of the energy supply system can be changed by the involvement of various technologies. As a result, optimal energy supply options could depend on various parameters that depend on specific contexts. In this study, different options to supply energy to apartment buildings of different energy efficiency levels in Sweden are investigated. Different renewable-based alternatives to produce heat and electricity based on various state-of-the-art technologies are considered. The optimizations are based on the hourly variation throughout the year of energy demand and of different energy supply systems that change with the ambient conditions such as temperature and solar radiation. The results prove that optimal options for a building depend on its scale of energy demand and on the availability of technologies in the market. Also, there is a tradeoff between monetary costs and primary energy use in supplying energy to apartment buildings. This study shows that it is essential to consider the interaction between energy demand and supply to estimate the costs and primary energy use for energy supply alternatives. A heating system with an electric heat pump shows to be primary energy efficient option whereas that with a wood pellet boiler is a more cost efficient once. However, an energy supply option based on a combined heat and power unit using fuel cell technology could potentially be the most cost- and primary energy efficient option for buildings with low energy demand.

Place, publisher, year, edition, pages
American Council for an Energy Efficient Economy, 2016
Keywords
building energy demand, combined heat and power, energy efficiency
National Category
Energy Systems Building Technologies
Identifiers
urn:nbn:se:lnu:diva-57662 (URN)
Conference
ACEEE Summer Study on Energy Efficiency in Buildings. August 21 - 26, 2016, California, USA
Available from: 2016-10-28 Created: 2016-10-28 Last updated: 2017-05-18Bibliographically approved
Truong, N. L. & Gustavsson, L. (2016). Effects of energy efficiency measures in district-heated buildings on energy systems. In: Proceedings of International Conference on Sustainable Built Environment - SBE 16.  March 8 - 11, 2016, Hamburg, Germany: . Paper presented at International Conference on Sustainable Built Environment - SBE 16. March 8 - 11, 2016, Hamburg, Germany. International Sustainable Built Environment
Open this publication in new window or tab >>Effects of energy efficiency measures in district-heated buildings on energy systems
2016 (English)In: Proceedings of International Conference on Sustainable Built Environment - SBE 16.  March 8 - 11, 2016, Hamburg, Germany, International Sustainable Built Environment , 2016Conference paper, Published paper (Refereed)
Abstract [en]

The primary energy savings depend on both the final energy savings and the energy efficiency of the supply system. In this study, we evaluate primary energy savings of different energy efficiency measures in a multistory district-heated building in Sweden. We consider various locations of the building with different district heat production systems (DHS) of different scales, technical charac-teristics and heat-load profiles. We show that the primary energy savings of the energy efficiency measures vary with the type of measure and with the type of energy supply systems. The energy efficiency measures give large final energy savings but their primary energy savings vary signifi-cantly. Of the energy efficiency measures, the measure that gives electricity savings but increase the use of district heat is the most primary energy efficient in relation to the final energy savings. Heat savings in buildings connected to small-scale DHS using heat-only boilers is more primary energy efficient than that in buildings connected to medium- and large- scale DHS using combined heat and power units. Evaluation of energy efficiency measures for district-heated buildings re-quires a systems perspective where the final energy savings in buildings are matched to the actu-al energy supply systems.

Place, publisher, year, edition, pages
International Sustainable Built Environment, 2016
Keywords
energy efficiency, district heated building, primary energy use, district heat
National Category
Construction Management Energy Engineering
Identifiers
urn:nbn:se:lnu:diva-57663 (URN)
Conference
International Conference on Sustainable Built Environment - SBE 16. March 8 - 11, 2016, Hamburg, Germany
Note

Ej belagd 170314

Available from: 2016-10-28 Created: 2016-10-28 Last updated: 2017-05-18Bibliographically approved
Organisations

Search in DiVA

Show all publications