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Gustafsson, M. (2018). Energy efficiency measures in the built environment - some aspects to consider in Sweden. (Doctoral dissertation). Gävle: Gävle University Press
Open this publication in new window or tab >>Energy efficiency measures in the built environment - some aspects to consider in Sweden
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The traditional energy system as we know it today will change in the future. There is a worldwide concern about the global warming situation and there are different actions implemented to limit the consequences from, mainly, the use of fossil fuels.

In this thesis, multi-unit apartment buildings have been simulated according to how the global CO2 emissions change when different energy efficiency measures are implemented. The simulated buildings have also been used to investigate how the calculated energy efficiency of a building according to Swedish building regulations varies depending on which technology for heating is used in the building and if the building has a solar PV installation or solar thermal system. When the energy efficiency of a building is calculated accord-ing to Swedish building regulations, this thesis shows that heat pumps are a favored technology compared to district heating. Another result is that electric-ity use/production within the investigated district heating system is the most important factor to consider when minimizing global CO2 emissions.

This thesis also investigates how the configuration of electric meters owned by the distribution system operator affects the monitored amount of self-consumed and produced excess electricity. Finally, four local low-voltage distri-bution networks were simulated when a future charging scenario of electric vehicles was implemented.

If a single-family house installs a solar PV installation, this thesis reveals that the configuration of the electric meter is important for the monitored amount of self-consumed electricity. This thesis also shows that the investigated low-voltage distribution networks can handle future power demand from electric vehicles and a high share of solar PV installations, but rural low-volt-age distribution networks will need to be reinforced or rebuilt to manage the investigated future scenarios.

Abstract [sv]

Sammanfattning Det traditionella energisystem som vi är vana vid idag kommer att förändras i framtiden. Oron för växthuseffekten och dess konsekvenser medför att olika åtgärder genomförs, framförallt för att minska koldioxidutsläppen från fossila bränslen.

I denna avhandling har flerfamiljshus simulerats med avseende på energi-användningen när olika energieffektiviseringsåtgärder implementeras. Resultatet av förändringarna i globala koldioxidutsläpp har sedan beräknats för de olika energieffektiviseringsåtgärderna. De simulerade resultaten har även använts för att analysera hur en byggnads energieffektivitet enligt Boverkets byggregler varierar med olika uppvärmningssätt och om byggnaden har en solvärme- eller solcellsanläggning installerad.

Denna avhandling visar att värmepumpar favoriseras jämfört med användning av fjärrvärme när en fastighets energieffektivitet beräknas enligt Boverkets byggregler. Samtidigt visas att den viktigaste åtgärden för att minska de globala koldioxidutsläppen är att minska elanvändningen eller att öka elproduktionen lokalt inom det studerade fjärrvärmeområdet.

Avhandlingen undersöker också hur konfigureringen av kundens elmätare i elnätet påverkar den uppmätta andelen egenanvänd och överproducerad el. Slutligen har fyra lokala lågvoltsnät simulerats då ett framtida scenario för laddning av elfordon adderats till fastigheternas nuvarande elanvändning.

Resultaten visar att om en villafastighet installerar en solcellsanläggning så påverkar konfigureringen av kundens elmätare den uppmätta andelen egenanvänd och överproducerad el och skillnaden kan vara relativt stor. Avhandlingen visar också att delar av lågvoltselnätet klarar en stor andel elfordon och en hög andel solcellsanläggningar men att landsbygdsnätet behöver förstärkas för att klara den ökade lasten i de antagna scenarierna.

Place, publisher, year, edition, pages
Gävle: Gävle University Press, 2018. p. 55
Series
Studies in the Research Profile Built Environment. Doctoral thesis ; 9
Keywords
primary energy, energy efficiency, district heating, building regulations, electric meter, low-voltage distribution networks, electric vehicles, primärenergi, energieffektivitet, fjärrvärme, byggregler, elmätare, elnät, elfordon
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-27986 (URN)978-91-88145-31-4 (ISBN)978-91-88145-32-1 (ISBN)
Public defence
2018-12-14, 13:111, Kungsbäcksvägen 47, Gävle, 13:00 (English)
Opponent
Supervisors
Available from: 2018-11-20 Created: 2018-10-01 Last updated: 2018-12-20
Gustafsson, M. (2017). Challenges for decision makers when feed in tariffs or net metering schemes change to incentives dependent of a high share of self-consumed electricity. In: 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC): . Paper presented at 2017 IEEE Photovoltaic Specialists Conference, PVSC-44, 25-30 June 2017, Washington DC, USA (pp. 2025-2030). IEEE conference proceedings
Open this publication in new window or tab >>Challenges for decision makers when feed in tariffs or net metering schemes change to incentives dependent of a high share of self-consumed electricity
2017 (English)In: 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC), IEEE conference proceedings, 2017, p. 2025-2030Conference paper, Published paper (Refereed)
Abstract [en]

When there are differences in economic value of self-consumed and exported electricity, profitable PV installations are dependent on accurate predictions of self-consumed electricity. In this study, minute-based data of PV production and electricity use were logged in a single-family house in Sweden. It is shown that when self-consumed electricity is measured, a low time resolution and different electric meter configurations can result in 60% lower registered self-consumed electricity than predicted. When feed-in tariffs or net metering schemes change to incentives dependent on the fraction of self-consumed electricity, the market and electric meter infrastructure must be prepared to avoid market disturbances.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2017
Keywords
government, policy, market incentives, feed-in tariffs, net metering, self-consumption
National Category
Other Engineering and Technologies
Identifiers
urn:nbn:se:hig:diva-26121 (URN)10.1109/PVSC.2017.8366092 (DOI)000455636002010 ()978-1-5090-5606-4 (ISBN)978-1-5090-5605-7 (ISBN)
Conference
2017 IEEE Photovoltaic Specialists Conference, PVSC-44, 25-30 June 2017, Washington DC, USA
Available from: 2018-02-09 Created: 2018-02-09 Last updated: 2019-03-19Bibliographically approved
Gustafsson, M., Karlsson, B. & Rönnelid, M. (2017). How the electric meter configuration affect the monitored amount of self-consumed and produced excess electricity from PV systems: case study in Sweden. Energy and Buildings, 138, 60-68
Open this publication in new window or tab >>How the electric meter configuration affect the monitored amount of self-consumed and produced excess electricity from PV systems: case study in Sweden
2017 (English)In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 138, p. 60-68Article in journal (Refereed) Published
Abstract [en]

This study evaluates how the principal function of bi-directional electric meters affects the monitored amount of self-consumed and produced excess electricity for dwelling buildings connected to the grid by three phases. The electric meters momentarily record the sum of the phases or the phases individually and then summarize the recorded values to a suitable time period and is then collected by the grid owner. In Sweden, both electric meter configurations fulfill laws and regulations.

The meter configuration affects the monitored distribution of self-consumed and produced excess electricity significantly for the investigated single-family house but is negligible for the investigated multi-dwelling buildings. The monitored self-consumed electricity produced by the PV installation for the single-family house varies between 24% and 55% depending on the configuration and how the inverter is installed for the investigated year. The difference in economic value for the produced electricity varies between 79.3 to 142 Euros.

Due to the electric meter configuration, the profitability of PV systems will be different for identical single-family houses with identical conditions. This should be corrected for a well-functioning market. It is also important to decide how the configuration should be designed to ensure that different incentives and enablers results in desired effects.

Keywords
Buildings, Commerce, Electric measuring instruments, Electric power generation, Energy policy, Houses, Housing, Laws and legislation, Energy markets, Identical conditions, Laws and regulations, Principal functions, PV installations, PV system, Single-family house, Solar PVs, Electric power transmission networks
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-21397 (URN)10.1016/j.enbuild.2016.11.010 (DOI)000394061200006 ()2-s2.0-85006846894 (Scopus ID)
Funder
Knowledge Foundation
Note

The work has been carried out under the auspices of the industrial post-graduate school Reesbe, which is financed by the Knowledge Foundation (KK-stiftelsen).

Available from: 2016-04-08 Created: 2016-04-08 Last updated: 2018-10-01Bibliographically approved
Gustafsson, M., Thygesen, R., Karlsson, B. & Ödlund, L. (2017). Rev-Changes in Primary Energy Use and CO2 Emissions: An Impact Assessment for a Building with Focus on the Swedish Proposal for Nearly Zero Energy Buildings. Energies, 10(7), Article ID 978.
Open this publication in new window or tab >>Rev-Changes in Primary Energy Use and CO2 Emissions: An Impact Assessment for a Building with Focus on the Swedish Proposal for Nearly Zero Energy Buildings
2017 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 7, article id 978Article in journal (Refereed) Published
Abstract [en]

In the European Union's Energy Performance of Buildings Directive, the energy efficiency goal for buildings is set in terms of primary energy use. In the proposal from the National Board of Housing, Building, and Planning, for nearly zero energy buildings in Sweden, the use of primary energy is expressed as a primary energy number calculated with given primary energy factors. In this article, a multi-dwelling building is simulated and the difference in the primary energy number is investigated when the building uses heat from district heating systems or from heat pumps, alone or combined with solar thermal or solar photovoltaic systems. It is also investigated how the global CO2 emissions are influenced by the different energy system combinations and with different fuels used. It is concluded that the calculated primary energy number is lower for heat pump systems, but the global CO2 emissions are lowest when district heating uses mostly biofuels and is combined with solar PV systems. The difference is up to 140 tonnes/year. If the aim with the Swedish building code is to decrease the global CO2 emissions then the ratio between the primary energy factors for electricity and heat should be larger than three and considerably higher than today.

Keywords
Emissions (Air pollution), Building, Energy consumption, Dwellings, Heat pumps, decentralized energy generation systems, district heating, energy performance of buildings, heat pump, primary energy, primary energy factors
National Category
Energy Engineering
Identifiers
urn:nbn:se:hig:diva-24872 (URN)10.3390/en10070978 (DOI)000406700200149 ()2-s2.0-85042470517 (Scopus ID)
Funder
Knowledge Foundation
Available from: 2017-08-17 Created: 2017-08-17 Last updated: 2018-10-01Bibliographically approved
Francisco Contero, J., Gomes, J., Gustafsson, M. & Karlsson, B. O. (2017). The impact of shading in the performance of three different solar PV systems. In: PROCEEDINGS OF THE 11TH ISES EUROSUN 2016 CONFERENCE: . Paper presented at 11th ISES EuroSun Conference, 11-14 October 2017, Palma, Spain (pp. 1168-1179). INTL SOLAR ENERGY SOC
Open this publication in new window or tab >>The impact of shading in the performance of three different solar PV systems
2017 (English)In: PROCEEDINGS OF THE 11TH ISES EUROSUN 2016 CONFERENCE, INTL SOLAR ENERGY SOC , 2017, p. 1168-1179Conference paper, Published paper (Refereed)
Abstract [en]

Partial shading decreases the performance of PV modules due to the series connection between the solar cells. In the recent years, several new technologies have emerged within the photovoltaics field to mitigate the effect of shading in the performance of the PV modules. For an accurate assessment of the performance of these devices, it is required to evaluate them comparatively in different circumstances. Three systems with six series-connected PV modules (each containing 60 cells) have been installed at the University of Gavle. System One comprises a string inverter system with 6 PV modules; System Two features a DC-DC optimizer per panel and a string inverter; System Three incorporates three micro inverters for six modules. A major conclusion of this study was that under partial shading of one (or more) modules both System Two (DC-DC optimizers) and System Three (micro inverters) perform considerably better than System One (string inverter), as long as the Impp of the shadowed module is lower than the Impp of the unshaded string It is also important that the Vmpp in the shaded module is higher than the lowest allowed voltage of the DC-DC optimizer or module inverter. The economic implications of the usage of these devices were also analyzed.

Place, publisher, year, edition, pages
INTL SOLAR ENERGY SOC, 2017
Keywords
Shading; PV-cells; DC-DC; inverter; installation; Impp; Vmpp; Pmax
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-26397 (URN)10.18086/eurosun.2016.08.25 (DOI)000426895100118 ()
Conference
11th ISES EuroSun Conference, 11-14 October 2017, Palma, Spain
Funder
Swedish Energy Agency, P38194-1
Available from: 2018-04-03 Created: 2018-04-03 Last updated: 2019-11-05Bibliographically approved
Gustafsson, M., Rönnelid, M., Trygg, L. & Karlsson, B. (2016). CO2 emission evaluation of energy conserving measures in buildings connected to a district heating system: case study of a multi-dwelling building in Sweden. Energy, 111, 341-350
Open this publication in new window or tab >>CO2 emission evaluation of energy conserving measures in buildings connected to a district heating system: case study of a multi-dwelling building in Sweden
2016 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 111, p. 341-350Article in journal (Refereed) Published
Abstract [en]

When taking action to fulfill the directives from the European Union, energy conserving measures will be implemented in the building sector. If buildings are connected to district heating systems, a reduced heat demand will influence the electricity production if the reduced heat demand is covered by combined heat and power plants.

This study analyze five different energy conserving measures in a multi-dwelling building regarding how they affect the marginal production units in the district heating system in Gävle, Sweden. For CO2 emission evaluations, two different combinations of heat and electricity conserving measures are compared to an installation of an exhaust air heat pump.

The different energy conserving measures affect the district heating system in different ways. The results show that installing an exhaust air heat pump affects the use/production of electricity in the district heating system most and electricity conserving measures result in reduced use of electricity in the building, reduced use of electricity for production of heat in the district heating system and an increase of electricity production.

The conclusion is that electricity use in the building is the most important factor to consider when energy conserving measures are introduced in buildings within the district heating system in Gävle.

Keywords
District heating system, Energy efficiency, Greenhouse gases, Refurbishment, Simulation
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-21396 (URN)10.1016/j.energy.2016.05.002 (DOI)000384776900029 ()2-s2.0-84973177469 (Scopus ID)
Funder
Knowledge Foundation
Available from: 2016-04-08 Created: 2016-04-08 Last updated: 2018-10-01Bibliographically approved
Gustafsson, M. (2016). Effects of different time resolution when self-consumed and produced excess electricity is predicted in a single family house: case study in cold climate, Sweden. In: : . Paper presented at 6th International Photovoltaic Science and Engineering Conference, PVSEC-26, Singapore, 24-28 October 2016.
Open this publication in new window or tab >>Effects of different time resolution when self-consumed and produced excess electricity is predicted in a single family house: case study in cold climate, Sweden
2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Other Engineering and Technologies
Identifiers
urn:nbn:se:hig:diva-26120 (URN)
Conference
6th International Photovoltaic Science and Engineering Conference, PVSEC-26, Singapore, 24-28 October 2016
Available from: 2018-02-09 Created: 2018-02-09 Last updated: 2018-03-13Bibliographically approved
Gustafsson, M. (2016). Evaluation of energy conserving measures in buildings connected to a district heating system: case studies in Gävle, Sweden. (Licentiate dissertation). Gävle: Gävle University Press
Open this publication in new window or tab >>Evaluation of energy conserving measures in buildings connected to a district heating system: case studies in Gävle, Sweden
2016 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

When different energy conserving measures are implemented for reducing energy use in buildings and the buildings are connected to district heating systems, it is important that an overall system analysis is made which takes into account the effects of total change of energy use due to the energy conserving measures.

The method applied in this thesis uses hourly production data for the different production units in the district heating system in Gävle, Sweden. The merit order of the different production units is dependent on the electricity spot market price. To calculate the merit order, hourly data for the electricity price is used. The marginal production unit can then be determined for each hour of the investigated year.

This thesis analyzes five different energy conserving measures in a multi-dwelling building regarding how they affect the marginal production units in the district heating system. For CO2 emission evaluations, two different combinations of heat and electricity conserving measures are compared to installation of an exhaust air heat pump. This thesis also analyzes how the configuration of the electric meter affects the measured amount of self-consumed and produced excess electricity for a single-family house and for two multi-dwelling buildings of different sizes.

The results show that the use of electricity is the most important objective to consider. The increased use of electricity for operation of the heat pump contributes to an increase of global CO2 emissions and the electricity produced by the solar photovoltaic installation contributes to a decrease of global CO2 emissions.

The results also show that the configuration of the electric meter is important for the single-family house but negligible for the multi-dwelling buildings. The amount of produced excess electricity is high for all buildings, which means that the economic value of produced excess electricity is important for a profitable installation.

Place, publisher, year, edition, pages
Gävle: Gävle University Press, 2016
Series
Studies in the Research Profile Built Environment. Licentiate thesis ; 1
Keywords
energieffektivisering, miljonprogrammet, solceller
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-21398 (URN)978-91-88145-03-1 (ISBN)978-91-88145-04-8 (ISBN)
Presentation
2016-06-09, Sal 99:132, Kungsbäcksvägen 47, Gävle, 10:30 (Swedish)
Opponent
Supervisors
Funder
Knowledge Foundation
Available from: 2016-06-07 Created: 2016-04-08 Last updated: 2018-03-13Bibliographically approved
Contero, F., Gomes, J., Gustafsson, M. & Karlsson, B. O. (2016). The impact of shading in the performance of threee different solar PV systems. In: : . Paper presented at 11th ISES Eurosun 2016, International Conference on Solar Energy for Buildings and Industry, 11-14 October 2016, Palma, Mallorca.
Open this publication in new window or tab >>The impact of shading in the performance of threee different solar PV systems
2016 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-25761 (URN)
Conference
11th ISES Eurosun 2016, International Conference on Solar Energy for Buildings and Industry, 11-14 October 2016, Palma, Mallorca
Available from: 2017-12-07 Created: 2017-12-07 Last updated: 2019-11-05Bibliographically approved
Gustafsson, M.Impacts of different electric vehicle charging strategies on low voltage distribution networks, a case study for Sweden.
Open this publication in new window or tab >>Impacts of different electric vehicle charging strategies on low voltage distribution networks, a case study for Sweden
(English)Manuscript (preprint) (Other academic)
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-27982 (URN)
Available from: 2018-09-30 Created: 2018-09-30 Last updated: 2018-10-04Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-3138-5508

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