| 1. |
- Avelin, Anders, 1966-, et al.
(författare)
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Effect of different renovation actions, their investment cost and future potential
- 2017
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Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; 143, s. 73-79
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Tidskriftsartikel (refereegranskat)abstract
- 65% of the buildings in Västerås, situated in the region of Mälardalen, Sweden were built before 1970. It is thus time for renovation. The situation is the same in most cities in Sweden and Northern Europe. The depth of renovation can be quite different. In this paper we evaluate some examples where cost is compared to energy saving effect. How to plan renovation to make use of the available capital in the cities is discussed. As a complement to direct renovation actions also behavior change with respect to energy is discussed and exemplified. The cost for energy actions in relation to other renovation aspects is discussed especially for the passive house case in Allingsås, Sweden. The passive house center calculate an extra cost for passive house standard to be 10 000 €/apartment while an external consultant has the figure 40 000 € of the total cost of 120 000 €. With this space heating can be 18 kWh/m2.year, or a reduction by 84 % with respect to space heating and 62% for overall heat and hot water demand. If you use the latter cost figure passive house standard is not motivated from an energy savings perspective while if using the lower figure it is very interesting. For the other less deep renovations we see that adding more insulation and three glass windows is motivated if the degradation has been strong, while a simpler renovation may be ok if the outer surface coating is not too bad. For these less deep renovations we see cost figures of 65 €/m2 respectively 28 €/m2 with reduction of heating and hot water demand of 56 % respectively 34 %.
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| 2. |
- Avelin, Anders, 1966-
(författare)
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Process Modeling of Combustion and Digesters for On-line Applications
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The use of biomass has increased in recent years due to the efforts to reduce the high emissions of greenhouse gases, primarily carbon dioxide from combustion of fossil fuels. At the same time industrial processes have become more complex because of increased production rates and profitability requirements. A higher degree of automation is needed when the processes are too complex to be handled manually. There is a need to find modeling strategies that can automatically handle the challenges that the conversion of biomass in an industrial process entails, such as operational changes, decreasing component and overall system efficiency, drifting sensors, etc. The objective of this thesis is to develop a methodology for on-line applications in industrial processes. Dynamic process models have been developed for continuous digesters and boilers. Process models have been evaluated for their use in continuous industrial process. Applications that have been studied are monitoring and diagnostics, advanced control and decision support. The process models are designed for on-line simulations. The results shows that the use of mathematical simulation models can improve the use of both process data and process understanding, to achieve improved diagnostics, advanced control and process optimization. In the two examples of industrial processes covered in this thesis, we can see that similar types of models can be used for completely different types of processes, such as pulp digesters and boilers. It also demonstrates the ability to combine soft sensors and hard sensors with physical models to take the information to a higher level of utilization.
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| 3. |
- Bian, Caiyun, et al.
(författare)
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Finding the optimal location for public charging stations - A GIS-based MILP approach
- 2019
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Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 6582-6588
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Konferensbidrag (refereegranskat)abstract
- Electric Vehicles (EVs) have achieved a significant development because of the continuous technology revolution and policy supports in recent years, which leads to a larger demand of charging stations. Strategies about how to find the optimal location for charging facilities are urgently needed in order to further assist the development of EVs. This paper focus on the return of investments on EV charging stations and proposes a Mixed Integer Linear Programming (MILP) model based on Geographic Information System (GIS) to identify the optimal location of charging stations in cities. Traffic flow data and land-use classifications are used as important inputs, and six important constraints are included in the MILP model with the objective function of maximizing the total profits of new charging stations. The effectiveness of the proposed method is then demonstrated by implementing a case study in Västerås, Sweden.
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| 4. |
- Dahlquist, Erik, 1951-, et al.
(författare)
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Control of waste water treatment combined with irrigation
- 2019
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Konferensbidrag (refereegranskat)abstract
- In waste water treatment using biological treatment processes normally phosphorous, nitrous compounds as well as organic matterare removed.It is also important to remove or kill pathogens that otherwisecould cause diseases. The surplus of bio-sludge is used to produce biogas. In thepaper four different alternatives for system design and operations of systems was discussed. The alternatives integrates thewaste water treatment and irrigation offarmland using the water taken out from different positions in the waste water treatment plant.
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| 5. |
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| 6. |
- Daraei, Mahsa, 1991-, et al.
(författare)
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Evaluation of biofuel production integrated with existing CHP plants and the impacts on production planning of the system – A case study
- 2019
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 252
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Daraei, Mahsa, 1991-, et al.
(författare)
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Evaluation of potential fossil fuel free energy system: Scenarios for optimization of a regional integrated system
- 2017
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 142, s. 964-970
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Tidskriftsartikel (refereegranskat)abstract
- Population growth and urbanization have led to increases in energy demand and consequently, greenhouse gas emissions. Therefore, the availability of the fossil fuel as the main source of energy supply has been changed. Utilization of renewable resources including solar, wind, and hydropower together with distributed energy systems could eliminate the dependency on fossil fuel energy sources. In this paper, energy use and supply trends have been studied for the Counties of Västmanland and Södermanland in Sweden in order to develop a scenario for the regional energy system in 2030. The aim is to use the scenario for evaluation of the impacts of regional renewable energy resources on the production planning of CHP plants. The scenario shows that there is not enough potential for electricity production from renewable resources such as solar, wind, and hydropower to fulfill the estimated demand in 2030. Around 75% of electricity needs in Västmanland and 89% of power demands in Södermanland need to be met by imported electricity to these regions. Efficiency improvements and a more complex energy system integrating also with other energy resources like biomass, waste and industrial waste heat are necessary to develop a sustainable energy system.
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| 8. |
- Daraei, Mahsa, 1991-, et al.
(författare)
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Impacts of integrating pyrolysis with existing CHP plants and onsite renewable-based hydrogen supply on the system flexibility
- 2021
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 43
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The share of renewable energy sources in the primary energy use is increasing worldwide. Given the intermittency of the energy supply from renewables, it is important to increase flexibility in the system to respond to the imbalances between energy demand and supply. Several flexibility options such as power storage and energy integration are currently in use, mostly at small scales. The increased energy supply from renewables and the flexibility solutions can influence the production planning of existing thermal energy conversion plants. In this study, integration of energy technologies including a hydrotreated pyrolysis oil production integrated with existing CHP plants is investigated as a flexibility solution. The system interacts with potential power generation from rooftop PV systems integrated with power-to-hydrogen storage. A cost-optimization model is developed using MILP method. The study focuses on the system flexibility and operational strategy of the existing CHP plants considering market trends, climate changes, and future energy developments with increased penetration of heat pumps and electric vehicles but less fossil fuels use. The results indicate that the suggested integrated system can increase the local energy supply by 33 GWh. Moreover, the power-to-hydrogen storage and onsite hydrogen use can increase the share of renewables in energy supply by 6%. Optimization of the developed scenarios for future energy-related changes indicates that the market trends could significantly reduce the performance of the system by 21% but increase the penetration of renewables in the system by 8%. Overall, scenario analysis shows the potential of using such a polygeneration system for flexible energy supply including existing CHP plants.
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| 9. |
- Daraei, Mahsa, 1991-, et al.
(författare)
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Optimization of a regional energy system including CHP plants and local PV system and hydropower : Scenarios for the County of Västmanland in Sweden
- 2019
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 230, s. 1111-1127
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Tidskriftsartikel (refereegranskat)abstract
- Providing the energy needs of the cumulatively increasing population has become a challenge for the regional energy systems in the world. The most critical challenge is to supply enough energy in the forms of heat and power during the cold and warm periods of the year with the lowest production cost and minimum environmental impacts. A solution is to increase the green energy supply from renewable energy resources such as solar, wind power, and hydropower. In order to apply this solution in the real energy system, potentials for clean energy supply in an optimized manner should be evaluated. In this study, an optimization model is developed for a regional energy system in the central part of Sweden. The studied system consists of Combined Heat and Power (CHP)plants and heat water boilers together with renewable energy supply from rooftop Photo Voltaic (PV)- solar collectors and regional hydropower plants. The General Algebraic Modeling System (GAMS)is used to create the model based on the Mixed Integer Linear Programming (MILP)method. The goal is to evaluate the influence of local renewable energy systems on the production planning of CHP plants in a region. Two different scenarios are investigated based on the extremes in energy supply and demand concerning the increased use of Electrical Vehicles (EVs)and more application of Heat Pumps (HPs)in the system. The results show that installation of rooftop PV systems has the potential to reduce the electricity import to the region; however, it will at the same time reduce the operation time of the CHP plans during the summer period. With increased use of HPs for heating, the shut off time for CHP plants is further increased. Increase in electric passenger cars penetration in the system has no impacts on the production profiles of the plants. The regional electricity demand grows significantly by more utilization of EVs and increased application of heat pumps in the studied system. The high electricity demand will mainly be satisfied by importing electricity from outside the region together with low production from CHP plants and the power generated by the rooftop PV systems and regional hydropower. The developed optimization model with studied scenarios can be applied to other energy systems to increase the knowledge of production planning and feasibility of a fossil fuel free energy system.
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| 10. |
- Daraei, Mahsa, 1991-, et al.
(författare)
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Potential biofuel production in a fossil fuel free transportation system : A scenario for the County of Västmanland in Sweden
- 2019
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Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 1330-1336
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Konferensbidrag (refereegranskat)abstract
- Air pollution and increased CO2 concentration in atmosphere and other energy related issues caused a transformative shift in energy system which contributes to increased utilization of renewables as alternative to generate green energy carriers. The potential of renewable resources in different region and potential energy conversion have been largely considered by many researcher in many countries. The energy conversion technologies to produce heat, electricity, and transportation fuels have made impressive technical advances. Sweden has also been challenging with mitigation of CO2 emission and trying to shift into a fossil fuel free system in all energy sectors. This paper deals with the current status of fuel demand and supply in the transport sector in a County in Sweden. A scenario for a fossil fuel free transport sector at a regional level is developed to investigate the potential biofuel production from regionally produced straw. The results and analysis indicate that the potential for cereal based bioethanol production in the region is sufficient to meet the biofuel demand of the County. Using the fallow land for cereal cultivation, it is feasible to shift into a fossil fuel free transportation system where all passenger cars are fueled by bioethanol. The results and finding from the current paper will be used to develop further study on optimization of local biofuel production integrated with CHP plants considering application of other feedstock such as municipal wastes.
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