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| 2. |
- Sandström, Maria, et al.
(author)
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Hosting capacity of the power grid for electric vehicles - A case study on a Swedish low voltage grid
- 2022
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In: IOP Conference Series: Earth and Environmental Science. - : IOP Press. - 1755-1307 .- 1755-1315.
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Conference paper (peer-reviewed)abstract
- Hosting capacity (HC) is described as the maximum amount of new production or consumption that can be added to the grid without causing a violation. In this case study, a deterministic approach is used to investigate the HC of electric vehicle (EV) charging in a low-voltage grid, containing 13 detached single-family houses. It investigates how different parameters affect the HC, and what is causing the violation in the grid. Two different performance indices (PI) are used in the study: power cable overloading and voltage drop. The local grid is simulated for one year for four cases and the HC is derived for these. The cases are distinguished by two different violation thresholds for the voltage drop and two different implementation orders of the location of the charging. The results show that the HC of the grid is 6-11 EVs charging simultaneously. The difference in HC is primarily due to variation in the baseload through the year and location of charging. The cable between the substation and the first cable cabinet was the major contributor to the fault, and the PI causing the violation differed depending on what case was used.
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| 3. |
- Albaric, Michael, et al.
(author)
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Solar CombiSystems Promotion and Standardisation (COMBISOL project)
- 2008
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In: Eurosun 2008. - Lisbon.
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Conference paper (other academic/artistic)abstract
- Solar combisystems (SCS) are solar heating installations providing space heating as well as domestic hot water in buildings. Within a global solar thermal energy strategy, SCS are a key element to decrease the fossil energy demand for heating in existing and new buildings. This project will help to reduce the use of fossil fuels and hence also the emission of greenhouse gases. During 3 years December 2007 – December 2010), experts from research, testing institutes and industry will work in the aim to encourage an accelerated deployment of SCS market – hence a higher share of heat produced by solar energy - and promote an improved quality of the installed systems.
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| 4. |
- Andersen, Martin, 1985-, et al.
(author)
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Economic Analysis of Heat Distribution Concepts for a Small Solar District Heating System
- 2022
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In: Energies. - : MDPI. - 1996-1073. ; 15:13
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Journal article (peer-reviewed)abstract
- One challenge in today’s district heating systems is the relatively high distribution heat loss. Lowering distribution temperatures is one way to reduce operational costs resulting from high heat losses, while changing the distribution system from steel pipes to plastic pipes and changing the heat distribution concept can reduce investment costs. The result is that the overall life cycle cost of the district heating system is reduced, leading to the improved cost competitiveness of district heating versus individual heating options. The main aim of this study was to determine the most cost-efficient distribution system for a theoretical solar district heating system, by comparing the marginal life cycle cost of two different distribution systems. A secondary aim was to determine the influence of the employed pipe type and insulation level on the marginal life cycle cost by comparing detailed economic calculations, including differences in pipe installation costs and construction costs, among others. A small solar-assisted district heating system has been modeled in TRNSYS based on a real system, and this “hybrid” model is used as a basis for a second model where a novel distribution system is employed and the heating network operating temperature is changed. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most efficient both from an energy and cost perspective. The total life cycle costs vary less than 2% for a given distribution concept when using different pipe types and insulation classes, indicating that the investment costs are more significant than operational costs in reducing life cycle costs. The largest difference in life cycle cost is observed by changing the distribution concept, the novel concept having approximately 24% lower marginal life cycle cost than the “hybrid” system. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
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| 5. |
- Andersen, Martin, 1985, et al.
(author)
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Heat distribution concepts for small solar district heating systems – Techno-economic study for low line heat densities
- 2022
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In: Energy Conversion and Management: X. - : Elsevier BV. - 2590-1745. ; 15
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Journal article (peer-reviewed)abstract
- The high operating temperatures in today's district heating networks combined with the low energy demand of new buildings lead to high relative network heat losses. New networks featuring lower operating temperatures have reduced relative heat losses while enabling an increase in the use of solar heat. The primary aim of this study was to determine if a particular district heating system can be made more effective with respect to heat losses and useful solar energy, by considering different distribution concepts and load densities. A small solar assisted district heating system with a novel hybrid distribution system has been modelled based on a real case study. This model serves as a basis for two other models where the distribution system and heating network operating temperature is changed. A secondary aim of the study was to determine the economic implications of making these changes, by using costs estimates to calculate the contribution of essential system components to total system cost. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most energy efficient in a sparse network with a heat density of 0.2 MWh/m∙a and a performance ratio of 66%, while a conventional district heating system performs worst and has a performance ratio of less than 58% at the same heat density. In an extremely sparse network with heat density of 0.05 MWh/m∙a, the performance ratio is 41% and 30% for these systems, respectively. A simple economic analysis indicates that the novel distribution concept is also best from an economic point of view, reducing the initial investment cost by 1/3 compared to the conventional concept, which is the most costly. However, more detailed calculations are needed to conclude on this.
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| 6. |
- Andersen, Martin, 1985-, et al.
(author)
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Techno-Economic Analysis of Solar Options for a Block Heating System
- 2016
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In: Conference Proceedings: Eurosun 2016. - Palma De Mallorca : International Solar Energy Society.
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Conference paper (peer-reviewed)abstract
- An innovative small solar district heating system with one central heating plant and four solar substations has been built in Vallda Heberg, Sweden, to supply a new housing area with passive houses. The target solar fraction was 40% and the total system design, including heat distribution in the buildings, was based on previous experience and aimed to be simple and cost-effective. The main aim of this study was to determine whether the system can be designed in a more effective manner by change of distribution system and load density. TRNSYS models were calibrated against measured data and then used to predict the energy performance. Results indicate that lower distribution heat losses can be obtained by change to a distribution concept with lower operating temperatures, while potentially reducing cost. Changes in heat density cause reduced distribution losses and boiler supplied heat demand, with only minor effects on solar system yield.
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| 7. |
- Andersen, Martin, 1985, et al.
(author)
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Techno-economic analysis of solar options for a block-heating system
- 2018
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In: Solar Energy. - 0038-092X.
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Journal article (peer-reviewed)abstract
- An innovative small solar district heating system with one central heating plant and four solar substations has been built in Vallda Heberg, Sweden, to supply a new housing area with passive houses. The target solar fraction was 40% and the total system design, including heat distribution in the buildings, was based on previous experience and aimed to be simple and cost-effective. The main aim of this study was to determine whether the system can be designed in a more effective manner by change of distribution system and load density. TRNSYS models were calibrated against measured data and then used to predict the energy performance. Results indicate that lower distribution heat losses can be obtained by change to a novel distribution concept with lower operating temperatures, while potentially reducing cost. Increases in heat density cause reduced distribution losses and boiler supplied heat demand, with only minor effects on solar system yield.
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| 8. |
- Bales, Chris, et al.
(author)
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Advanced Storage Concepts For Solar Houses And Low Energy Buildings - IEA-SHC Task 32
- 2005
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In: ISES Solar World Congress 2005. - Orlando, Florida, USA.
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Conference paper (other academic/artistic)abstract
- This paper presents the current status of the work in Task 32 (Advance Storage Concepts for Solar and Low Energy Buildings) of the International Energy Agency’s Solar Heating and Cooling Programme (IEA-SHC). A methodology for inter-comparison has been established and boundary conditions and reference systems for this have been defined. The current status of the projects range from recently concluded feasibility studies for chemical heat storage, to prototyping, lab testing, modelling and system simulation for advanced water stores, with and without PCM content, as well as for stores based on the sorption principle. Promising new components and solutions for more classical water tanks are also described in order to define market references.
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| 10. |
- Bales, Chris, et al.
(author)
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Chapter 12: Sorption and Themo-Chemical Storage
- 2005
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In: Thermal energy storage for solar and low energy buildings - State of the art. - Lleida, Spain : Lleida University. - 848409877X
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Book chapter (other academic/artistic)
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