| 1. |
- Chen, B., et al.
(författare)
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Pathways for sustainable energy transition
- 2019
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 228, s. 1564-1571
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Tidskriftsartikel (refereegranskat)abstract
- Energy transitions are ongoing processes all over the world. While sustainable solutions are envisioned for the future, many societies are still under high-carbon and high-pollution energy regime borne by fossil fuels. How to design pathways towards sustainable energy transition has attracted worldwide concerns. Understanding the possible transition pathways of the energy system requires the integration of new energy technologies, environmental sciences, economics and management. This Special Issue of Journal of Cleaner Production targets to collect the latest research results on sustainable energy systems, discover innovative avenues and inspiring models and share knowledge on energy system modelling and management. In this paper, we identify 4 themes on sustainable energy transition pathways including: (1)Sustainable energy economics and management; (2)Renewable energy generation and consumption; (3)Environmental impacts of energy systems; and (4)Electric vehicle and energy storage. Theories, technologies, innovative models, and successful experiences are discussed accordingly. It is suggested that creative, robust and audacious strategies in governance, management and education are needed to boost sustainable energy transition across various scales and sectors.
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| 2. |
- Gustafsson, Marcus, 1987-, et al.
(författare)
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Techno-economic analysis of energy renovation measures for a district heated multi-family house
- 2016
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 177, s. 108-116
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Tidskriftsartikel (refereegranskat)abstract
- Renovation of existing buildings is important in the work toward increased energy efficiency and reduced environmental impact. The present paper treats energy renovation measures for a Swedish district heated multi-family house, evaluated through dynamic simulation. Insulation of roof and façade, better insulating windows and flow-reducing water taps, in combination with different HVAC systems for recovery of heat from exhaust air, were assessed in terms of life cycle cost, discounted payback period, primary energy consumption, CO2 emissions and non-renewable energy consumption. The HVAC systems were based on the existing district heating substation and included mechanical ventilation with heat recovery and different configurations of exhaust air heat pump.Compared to a renovation without energy saving measures, the combination of new windows, insulation, flow-reducing taps and an exhaust air a heat pump gave up to 24% lower life cycle cost. Adding insulation on roof and façade, the primary energy consumption was reduced by up to 58%, CO2 emissions up to 65% and non-renewable energy consumption up to 56%. Ventilation with heat recovery also reduced the environmental impact but was not economically profitable in the studied cases. With a margin perspective on electricity consumption, the environmental impact of installing heat pumps or air heat recovery in district heated houses is increased. Low-temperature heating improved the seasonal performance factor of the heat pump by up to 11% and reduced the environmental impact.
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| 3. |
- Johansson, Björn, 1975, et al.
(författare)
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Power Level Sampling of Metal Cutting Machines for Data Representation in Discrete Event Simulation
- 2015
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Ingår i: International Journal of Production Research. - : Informa UK Limited. - 0020-7543 .- 1366-588X. ; 53:23, s. 7060-7070
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Tidskriftsartikel (refereegranskat)abstract
- An extension to the application area for discrete event simulation (DES) has been ongoing since the last decade and focused only on economic aspects to include ecologic sustainability. With this new focus, additional input parameters, such as electrical power consumption of machines, are needed. This paper aim at investigating how NC machine power consumption should be represented in simulation models of factories. The study includes data-sets from three different factories. One factory producing truck engine blocks, one producing brake disc parts for cars and one producing forklift components. The total number of data points analysed are more than 2,45,000, where of over 1,11,000 on busy state for 11 NC machines. The low variability between busy cycles indicates that statistical representations are not adding significant variability. Furthermore, results show that non-value-added activities cause a substantial amount of the total energy consumption, which can be reduced by optimising the production flow using dynamic simulations such as DES.
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| 4. |
- Zhang, Yang, et al.
(författare)
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Planning and operation of an integrated energy system in a Swedish building
- 2019
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Ingår i: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 199
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Tidskriftsartikel (refereegranskat)abstract
- More flexibility measures are required due to the increasing capacities of variable renewable energies (VRE). In buildings, the integration of energy supplies forms integrated energy systems (IES). IESs can provide flexibility and increase the VRE penetration level. To upgrade a current building energy system into an IES, several energy conversion and storage components are needed. How to decide the component capacities and operate the IES were investigated separately in studies on system planning and system operation. However, a research gap exists that the system configuration from system planning is not validated by actual operation conditions in system operation. Meanwhile, studies on system operation assume that IES configurations are predetermined. This work combines system planning and system operation. The IES configuration is determined by mixed integer linear programming in system planning. Actual operation conditions and forecast errors are considered in system operation. The actual operation profiles are obtained through year-round simulations of different energy management systems. The results indicate that the system configuration from system planning can meet energy demands in system operation. Among different energy management systems, the combination of robust optimization and receding horizon optimization achieves the lowest yearly operation cost. Meanwhile, two scenarios that represent high and low forecast accuracies are studied. Under the high and low forecast accuracy scenarios, the yearly operation costs are about 4% and 6% higher than that obtained from system planning.
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| 5. |
- Ghaviha, Nima, et al.
(författare)
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Review of Application of Energy Storage Devices in Railway Transportation
- 2017
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102.
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Konferensbidrag (refereegranskat)abstract
- Regenerative braking is one of the main reasons behind the high levels of energy efficiency achieved in railway electric traction systems. During regenerative braking, the traction motor acts as a generator and restores part of the kinetic energy into electrical energy. To use this energy, it should be either fed back to the power grid or stored on an energy storage system for later use. This paper reviews the application of energy storage devices used in railway systems for increasing the effectiveness of regenerative brakes. Three main storage devices are reviewed in this paper: batteries, supercapacitors and flywheels. Furthermore, two main challenges in application of energy storage systems are briefly discussed. © 2017 The Authors.
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| 6. |
- Rusu, Cristina, et al.
(författare)
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Challenges for Miniaturised Energy Harvesting Sensor Systems
- 2018
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Ingår i: 2018 10th International Conference on Advanced Infocomm Technology (ICAIT). - : Institute of Electrical and Electronics Engineers Inc.. - 9781538679364 ; , s. 214-217
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Konferensbidrag (refereegranskat)
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| 7. |
- Timmons, D., et al.
(författare)
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Cost minimization for fully renewable electricity systems : A Mauritius case study
- 2019
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Ingår i: Energy Policy. - : Elsevier Ltd. - 0301-4215 .- 1873-6777. ; 133
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is the world's most prominent environmental problem, and fossil-fuel combustion is its primary cause. To set carbon reduction goals, policy makers require information on feasibility and cost of renewable energy systems. In this study, we describe an economic approach to modeling a national electricity system based entirely on renewable sources, using the island-nation of Mauritius as a case study. Many renewable electricity studies consider levelized costs of electricity (LCOE), which represents average cost of electricity, but cost minimization requires equalizing marginal costs. With variable sources, marginal costs change over time. Minimizing cost thus requires a model incorporating variability at high time resolution (daily or hourly), with the objective of minimizing the levelized cost of electricity for an entire electricity system (LCOES). In Mauritius, the minimum-cost renewable electricity portfolio includes roughly equal proportions of solar, wind, and biomass electricity, along with electricity storage. Policy issues include setting renewable energy targets, selecting policy instruments to incentivize optimum renewable energy portfolios, incorporating energy efficiency, determining appropriate discount rates, ensuring land availability, and accounting for non-cost considerations. Many of the economic and policy issues identified apply universally, and methods demonstrated in this study could be used anywhere in the world.
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| 8. |
- Ringsberg, Jonas, 1971, et al.
(författare)
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Comparison of mooring solutions and array systems for point absorbing wave energy devices
- 2018
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Ingår i: Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE. - 9780791851326 ; 11A, s. 1-11
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Konferensbidrag (refereegranskat)abstract
- Most of the ocean energy technologies are considered to be ina pre-commercial phase and need technical development. Thisstudy focuses on design of mooring solutions and comparesarray systems of a specific floating point-absorbing waveenergy converter (WEC) developed by the companyWaves4Power. A full-scale prototype of the WEC is installedin Runde (Norway) where it is moored with three polyestermooring lines, each having one floater and one gravity anchor.Based on this reference installation, the method of systemsengineering was used to propose twenty-two conceptualmooring solutions for different array systems. They werecompared and reduced to four top concepts in a systematicelimination procedure using Pugh and Kesselring matrices. Thetop concepts were assessed in detail by means of LCOE(levelised cost of energy), LCA (life cycle analysis) and riskanalyses. The fatigue life of the mooring lines and the energycapture were calculated using results obtained from coupledhydrodynamic and structure response analyses in the DNV-GLDeepC software. Two final concepts were proposed for thewater depths 75 and 200 m.
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| 9. |
- Wang, S., et al.
(författare)
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Operational reliability of multi-energy customers considering service-based self-scheduling
- 2019
-
Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 254
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Tidskriftsartikel (refereegranskat)abstract
- The developments of energy storage and substitution techniques have made it possible for customers to self-schedule their energy consumption behaviors, to better satisfy their demands in response to uncertain supply conditions. The interdependency of multiple energies, the chronological characteristics, and uncertainties in the self-scheduling context bring about additional complexities to secure the reliable energy requirements of multi-energy customers. As a necessary and challenging task, the operational reliability of multi-energy customers is tackled in this paper. Considering that the consumed energies eventually come down to the energy-related services, the self-scheduling of multi-energy customers is implemented from the perspective of specific energy-related services rather than energy carriers. Firstly, an optimal self-scheduling model for multi-energy customers is developed with the consideration of chronological service curtailment, service shifting and possible failures during service shifting. In the optimal self-scheduling model, the costs of service curtailment and shifting are formulated based on the proposed evaluation method. The time-sequential Monte Carlo simulation approach is applied to model the chronological volatilities of multi-energy demands over the entire study period, embedded with a scenario reduction technique to reduce the computational efforts. Taking full account of the possible scenarios, the quantitative reliability indices of the multi-energy customers can be obtained. The results in test cases demonstrate that the expected energy not supplied of the multi-energy customer drops significantly by 56.32% with the self-scheduling strategy. It can be also concluded that, the self-scheduling and its inherent uncertainties do have significant impacts on the operational reliability of the multi-energy customer.
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| 10. |
- Chiu, Justin N. W., et al.
(författare)
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Industrial surplus heat storage in smart cities
- 2015
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Ingår i: ASME 2015 9th International Conference on Energy Sustainability, ES 2015, collocated with the ASME 2015 Power Conference, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum. - : American Society of Mechanical Engineers. - 9780791856857
-
Konferensbidrag (refereegranskat)abstract
- Surplus heat generated from industrial sectors amounts to between 20% and 50% of the total industrial energy input. Smart reuse of surplus heat resulted from industrial sectors and power generation companies is an opportunity to improve the overall energy efficiency through more efficient use the primary energy sources. A potential solution to tackle this issue is through use of thermal energy storage (TES) to match user demand to that of the generated surplus heat. A mobile TES (MTES) concept of transportation of industrial surplus heat from production sites to end customers has shown promising results. One commissioned demonstration project using industrial heat for swimming pool water temperature regulation in Dortmund, Germany proved the interest and attention given to this concept. In this paper, a techno-economic case study in Sweden of transportation of surplus thermal energy to district heating in smart cities is presented. The application consists of heat storage at 110°C- 130°C through the use of phase change materials (PCM) based TES, notably with use of Erythritol (90 kWh/ton) for the considered temperature range, to remote district heating network located at 48 km from the thermal energy generation site. The advantages of using latent heat based PCM are the high enthalpy density per unit volume and per unit mass, as well as the quasi-constant temperature during charging and releasing of heat. The M-TES in this study has a total storage capacity of 2.1 MWh, the optimization of charge/discharge time to the amount of stored/released energy and to that of energy transportation rate is presented in this paper. Contrary to logical thinking, it is shown through this work that under certain conditions, it is more cost-effective to operate at partial load of storage units albeit the increased number of transport trips and charge/discharge cycles.
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| 11. |
- Skagestad, Ragnhild, 1978, et al.
(författare)
-
GCCSI Webinar: Cutting Cost of CO2 Capture in Process Industry (CO2stCap) Project overview & first results for partial CO2 capture at integrated steelworks
- 2017
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- GCCSI Webinar: Cutting Cost of CO2 Capture in Process Industry (CO2stCap) Project overview & first results for partial CO2 capture at integrated steelworks This publication has the format of a webinar: The CO2StCap project is a four year initiative carried out by industry and academic partners with the aim of reducing capture costs from CO2 intensive industries (more information here). The project, led by Tel-Tek, is based on the idea that cost reduction is possible by capturing only a share of the CO2 emissions from a given facility, instead of striving for maximized capture rates. This can be done in multiple ways, for instance by capturing only from the largest CO2 sources at individual multi-stack sites utilising cheap waste heat or adapting the capture volumes to seasonal changes in operations. The main focus of this research is to perform techno-economic analyses for multiple partial CO2 capture concepts in order to identify economic optimums between cost and volumes captured. In total for four different case studies are developed for cement, iron & steel, pulp & paper and ferroalloys industries. The first part of the webinar gave an overview of the project with insights into the cost estimation method used. The second part presented the iron & steel industry case study based on the Lulea site in Sweden, for which waste-heat mapping methodology has been used to assess the potential for partial capture via MEA-absorption. Capture costs for different CO2 sources were discussed, demonstrating the viability of partial capture in an integrated steelworks.
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| 12. |
- Shivakumar, Abhishek, et al.
(författare)
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Drivers of renewable energy deployment in the EU : An analysis of past trends and projections
- 2019
-
Ingår i: Energy Strategy Reviews. - : Elsevier. - 2211-467X .- 2211-4688. ; 26
-
Tidskriftsartikel (refereegranskat)abstract
- Energy policy in the European Union (EU) is driven by the objective to transition to an affordable, reliable, and low carbon energy system. To achieve this objective, the EU has explicitly stated targets for greenhouse reduction, shares of renewable energy sources (RES), and energy efficiency improvements for 2020 and 2030. In this paper, we focus on the drivers, barriers and enablers to achieving the EU's RES targets (20% by 2020 and 27% by 2030). Effective energy policies play a key role in the deployment of RES technologies. In order to design effective policies, a clear understanding of past trends and projections for future deployment is required. In this paper, we first analyse the past deployment of RES technologies for electricity supply (RES-E) in selected EU Member States. This highlights the key drivers, barriers, and enablers for deployment of RES in the past. In a second step, we conduct a meta-analysis of projections for RES-E shares from multiple well-established studies. Such an analysis will help in supporting the design of more effective energy policies and successfully achieving the EU's energy targets.
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| 13. |
- Ekener, Elisabeth, 1963-, et al.
(författare)
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Developing Life Cycle Sustainability Assessment methodology by applying values-based sustainability weighting - Tested on biomass based and fossil transportation fuels
- 2018
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 181, s. 337-351
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Tidskriftsartikel (refereegranskat)abstract
- The production and use of transportation fuels can lead to sustainability impacts. Assessing them simultaneously in a holistic way is a challenge. This paper examines methodology for assessing the sustainability performance of products in a more integrated way, including a broad range of social impacts. Life Cycle Sustainability Assessment (LCSA) methodology is applied for this assessment. LSCA often constitutes of the integration of results from social LCA (S-LCA), environmental life cycle assessment (E-LCA) and life cycle costing (LCC). In this study, an S-LCA from an earlier project is extended with a positive social aspect, as well as refined and detailed. E-LCA and LCC results are built from LCA database and literature. Multi Criteria Decision Analysis (MCDA) methodology is applied to integrate the results from the three different assessments into an LCSA. The weighting of key sustainability dimensions in the MCDA is performed in different ways, where the sustainability dimensions are prioritized differently priority based on the assumed values of different stakeholder profiles (Egalitarian, Hierarchist, and Individualist). The developed methodology is tested on selected biomass based and fossil transportation fuels - ethanol produced from Brazilian sugarcane and US corn/maize, and petrol produced from Russian and Nigerian crude oils, where it delineates differences in sustainability performance between products assessed. The outcome in terms of relative ranking of the transportation fuel chains based on sustain ability performance differs when applying different decision-maker profiles. This result highlights and supports views that there is no one single answer regarding which of the alternatives that is most sustainable. Rather, it depends strongly upon the worldview and values held by the decision maker. A key conclusion is that sustainability assessments should pay more attention to potential differences in underlying values held by key stakeholders in relevant societal contexts. The LCSA methodology still faces challenges regarding results integration but MCDA in combination with stakeholder profiles appears to be a useful approach to build on further.
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| 14. |
- de Klijn-Chevalerias, M., et al.
(författare)
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The Dutch approach for assessing and reducing environmental impacts of building materials
- 2017
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Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323. ; 111, s. 147-159
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Tidskriftsartikel (refereegranskat)abstract
- Buildings are one of the largest consumers of energy and materials, and hence they are also one of the largest contributors to negative environmental impacts. Traditionally, energy consumed by buildings during their operation phase was the most significant in their lifecycles and far exceeded the embodied energy. However, in contemporary low-energy buildings, the embodied energy is proportionally higher because of the prevalent use of energy-intensive materials. To determine the embodied energy and environmental impacts of building materials, the Dutch have developed an assessment method, which has also been adapted by BREEAM-NL. This paper offers an overview of the Dutch approach for assessing the environmental impacts of building materials and demonstrates its practical application. The use of the Dutch Assessment Method to identify, and quantify materials-related design improvements has been demonstrated through an exemplifying case study. It has been identified that the environmental impact of a building is largely influenced by the material choices made at the early design stage of the project.
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| 15. |
- Vujanović, M., et al.
(författare)
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Special issue of applied energy dedicated to SDEWES conferences 2018 : Sustainable energy technologies and environmental impacts of energy systems
- 2019
-
Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 256
-
Tidskriftsartikel (refereegranskat)abstract
- This special issue of Applied Energy contains scientific articles presented at the 1st Latin American edition of the SDEWES conference conducted in 2018 in Rio de Janeiro, the 3rd South East Europe edition of SDEWES conference conducted in 2018 in Novi Sad, and the 13th SDEWES conference conducted in 2018 in Palermo. The SDEWES conferences are international scientific conferences that gather scientists and professionals from the field of sustainable development. These conferences have brought together 770 scientists, researchers, and experts in the field of sustainable development of energy and environment. This editorial is based upon 20 papers selected from among 700 contributions presented at the SDEWES conferences in 2018. The topics covered in this special issue include the advances in research and development in the energy sytems and technologies and its environmental impact within the framework of sustainable development.
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| 16. |
- Lv, Y., et al.
(författare)
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Performance of a hybrid solar photovoltaic - Air source heat pump system with energy storage
- 2019
-
Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 1311-1316
-
Konferensbidrag (refereegranskat)abstract
- The paper introduced a smart renewable energy based microgrid system which is composed of three subsystems: solar photovoltaic subsystem, air source heat pump subsystem and energy storage subsystem. This microgrid system was applied to the demonstration project located in Xining City, Qinghai Province, China. The energy performance of the smart renewable energy based microgrid system was evaluated and compared with that of traditional energy supply system which totally depends on the electricity grid and natural gas. The comparison study demonstrates that the proposed hybrid energy supply system is superior to traditional system, significantly decreasing additional energy consumption for buildings and reducing pollutant emissions.
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| 17. |
- Sun, Peikun, et al.
(författare)
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Analysis of camber control and torque vectoring to improve vehicle energy efficiency
- 2018
-
Ingår i: The Dynamics of Vehicles on Roads and Tracks. - : CRC Press/Balkema. - 9781138035713 ; 1, s. 121-128
-
Konferensbidrag (refereegranskat)abstract
- This paper focuses on the use of camber control and torque vectoring in order to make future vehicles more energy efficient and thereby more environmentally friendly. The energy loss during steady state cornering including rolling resistance loss, aerodynamic loss, longitudinal slip loss and lateral slip loss, is formulated and studied. Camber control, torque vectoring control and a combination of both are compared. From the simulation results, it can be concluded that during steady state cornering, torque vectoring has a very small contribution to energy reduction while camber control can make a significant contribution to energy saving. By combining torque vectoring and camber control during steady state cornering, in theory up to 14% energy saving are found for certain cases.
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| 18. |
- Raza, Rizwan, et al.
(författare)
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Fuel cell technology for sustainable development in Pakistan - An over-view
- 2016
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 53, s. 450-461
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Tidskriftsartikel (refereegranskat)abstract
- Fuel cell technology holds the combination of benefits, which are barely offered by any other energy generating technology. Because the fuel used in this technology is found in abundance in nature and can also be renewed/sustained. Pakistan is blessed with renewable energy resources which are suitable for fuel cell technology. Therefore, fuel cell technology offers a great opportunity to meet the demand of energy and for the sustainable development of Pakistan. The energy research group at COMSATS Institute of Information Technology (CIIT), Lahore has made efforts to study the technical aspects of fuel cell technology and its commercial benefits. The research group is interested in finding ways and means of generating and storing the energy produced by using fuel cells. In this paper, the research activities on fuel cell technology in Pakistan have been reviewed and it is also discussed how this technology can resolve the current energy crises in Pakistan and can be the source of sustainable energy. It has been also reviewed that the country would greatly benefit from fuel cells and fuel cell hybrid system (environmental friendly technology), which could be the best solution for electricity production as well for automobile industry.
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| 19. |
- Dipasquale, C., et al.
(författare)
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Database of energy, environmental and economic indicators of renovation packages for European residential buildings
- 2019
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Ingår i: Energy and Buildings. - : Elsevier Ltd. - 0378-7788 .- 1872-6178. ; 203
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Tidskriftsartikel (refereegranskat)abstract
- Increasing the energy efficiency with a vast impact in the residential building stock requires retrofit solutions that can be exploited with respect to a wide range of different building typologies and climates. Several tools and methodologies are nowadays available both for the assessment of building demands and for the individuation of optimum retrofit solutions. However, they are usually either too complex to be adopted by professionals or, on the contrary, oversimplified to account for the full complexity of a deep envelope and HVAC system retrofit. In this context, this paper describes a methodology developed to generate reliable information on retrofit solutions for typical buildings in different climatic conditions. Detailed numerical models are used to simulate a number of combinations of envelope and HVAC systems retrofit measures and renewable energy integration. Energy performance results are gathered in a database that allows comparing solutions, spanning over a range of more than 250,000 combinations of building types, age of construction, climates, envelope performance levels and HVAC systems configurations. Economic feasibility is also derived for each of the combinations. In this way, the accurateness of a detailed and validated calculation is made available to assist during the decision making process, with minimum computational effort being required by professionals: the variety and density of evaluated combinations allows to easily assess the performance of a specific case by interpolating among instances previously assessed. The applicability of the results to different climates and similar building typologies is verified by a comparison of the database results with a specific case dynamic simulation.
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| 20. |
- Tillig, Fabian, 1984, et al.
(författare)
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A generic energy systems model for efficient ship design and operation
- 2017
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Ingår i: Proceedings of the Institution of Mechanical Engineers Part M: Journal of Engineering for the Maritime Environment. - : SAGE Publications. - 2041-3084 .- 1475-0902. ; 231:2, s. 649-666
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Tidskriftsartikel (refereegranskat)abstract
- There is an evironmental and econimical motivated need to reduce the fuel consumption and air emmissions of ships. To achieve a reduction of the energy consumption, the energy flow in the entire energy system of a ship must be analyzed in both, the component, or subsystem level as well as in a holistic way to capture the interactions between the components. Of the currently available energy consumption monitoring and prediction methods or models, no single model or method can be used to asses the energy efficiency of an arbritary vessel in both the early design phase and operation of ships. This study presents a new generic ship energy systems model that can be used for this purpose. This new model has two parts: one for assessment of a ship’s energy consumption based on an ordinary static power prediction and one for advanced operational analysis, considering hydrodynamic and machinery systems effects. A Panamax tanker vessel was used as the case study vessel to prove the versatility of the model for five example simulations for the design and operation of ships. The examples include variations of the main dimensions, propeller design, engine layout and the operational profile on a North Atlantic route. From the results, different areas with a potential for energy savings were identified.
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| 21. |
- Hadin, Åsa
(författare)
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From waste problem to renewable energy resource : exploring horse manure as feedstock for anaerobic digestion
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A sustainable energy system requires, according to energy policies, reduced emissions of greenhouse gases, increased ratio of renewable sources of energy and more efficient use of energy. Horse manure could be regarded as waste, but also as a resource for renewable energy and plant nutrients. This thesis explores the potential of horse manure as a renewable energy source, and its possibilities to support and contribute to energy and environmental objectives. To do this, data was collected from literature, simulations, study visits and interviews.A number of horse keeping activities were identified in the assessment of horse manure as a feedstock for energy and as a plant resource: feeding, indoor housing, outdoor keeping, manure storage, fertilizing and transport, all with effect on amount and content of horse manure. Results indicated that choice and amount of bedding are important for both energy performance and plant nutrient content in the biofertilizer. Operational conditions such as long hydraulic retention time and high temperature had less impact for horse manure as a biogas feedstock. Anaerobic digestion resulted in the lowest global warming potential compared to incineration and composting, while large-scale incineration reduced primary energy demand, acidification potential and eutrophication potential. In a subsequent simulation, anaerobic digestion had lower potential environmental impact than unmanaged composting, regarding all chosen environmental impact categories in the study. Experiences from energy companies suggest that horse manure can be used in small quantities in co-incineration, with suitable incineration technology, but odor was mentioned as a problem. Farm-scale incineration required continuous maintenance and monitoring and mixing with pellets. As a feedstock for anaerobic digestion horse manure was regarded as suitable for plug-flow processes while stirred processes experienced more technical problems leading to increased cost for plants. With adaption of horse manure to the energy recovery technology to be used, and adaption at energy conversion plants to homogenous materials, this not yet fully utilized bioenergy resource has potential to contribute with renewable energy to the energy system, and thereby also reduce environmental impact from horse manure treatment
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| 22. |
- Ringsberg, Jonas, 1971
(författare)
-
Models and strategies
- 2017
-
Ingår i: Wave & Tidal Energy Network Magazine. ; :11, s. 27-27
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Wave Energy Group on the Division of Marine Technology on the Department of Mechanics and Maritime Sciences, Chalmers University of Technology, develops simulation models for structural integrity analysis of mooring lines and umbilical cables used in wave energy converter (WEC) systems. The article gives an overview of ongoing research projects and an outlook.
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| 23. |
- Jurasz, Jakob, PhD, 1990-, et al.
(författare)
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The potential of photovoltaic systems to reduce energy costs for office buildings in time-dependent and peak-load-dependent tariffs
- 2019
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Ingår i: Sustainable cities and society. - : Elsevier Ltd. - 2210-6707. ; 44, s. 871-879
-
Tidskriftsartikel (refereegranskat)abstract
- Electrical power generation across the world is facing dramatic changes for a variety of reasons related to reliability, economics and environmental concerns. Over recent years a significant increase has been observed in installed capacity of photovoltaic systems. Due to their typical seasonal and diurnal energy conversion patterns their integration into power systems creates new opportunities as well as threats. This paper intends to show how photovoltaics can contribute to reducing peak load in office buildings and thereby minimise expenditure on electricity during time- and peak-load-dependent energy prices/tariffs. An additional benefit is also provided to the national power system by reducing the need for peaking power stations. The calculations are performed for energy tariffs commonly used for commercial buildings in Poland. The simulation relies on climatic and price data for 2016. The results show significant potential for photovoltaics to reduce the peak load (from almost 60 kW to slightly over 44 kW) whilst simultaneously minimising energy costs to the building (from 1.2% up to 5.8% depending on the selected tariff). This study demonstrates the economic benefits of using PV system for reducing peak loads. A sensitivity analysis with regard to photovoltaics investment costs is carried out showing that the increasing investment costs have different impact on total energy cost depending on the considered energy tariff.
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| 24. |
- Thollander, Patrik, et al.
(författare)
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Energy efficiency as a wicked problem
- 2019
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- Together with increased shares of renewable energy supply, improved energy efficiency is the foremost means of mitigating climate change. However, the energy efficiency potential is far from being realized, which is commonly explained by the existence of various barriers to energy efficiency. Initially mentioned by Churchman, the term wicked problems became established in the 1970s, meaning a kind of problem that has a resistance to resolution because of incomplete, contradictory, or changing requirements. In the academic literature, wicked problems have later served as a critical model in the understanding of various challenges related to society, such as for example climate change mitigation. This aim of this paper is to analyze how the perspective of wicked problems can contribute to an enhanced understanding of improved energy efficiency. The paper draws examples from the manufacturing sector. Results indicate that standalone technology improvements as well as energy management and energy policy programs giving emphasis to standalone technology improvements may not represent a stronger form of a wicked problem as such. Rather, it seems to be the actual decision-making process involving values among the decision makers as well as the level of needed knowledge involved in decision-making that give rise to the wickedness. The analysis shows that wicked problems arise in socio-technical settings involving several components such as technology, systems, institutions, and people, which make post-normal science a needed approach.
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- Haraldsson, Joakim, 1990-, et al.
(författare)
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Impact analysis of energy efficiency measures in the electrolysis process in primary aluminium production
- 2019
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Ingår i: WEENTECH Proceedings in Energy. ; , s. 177-184
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Konferensbidrag (refereegranskat)abstract
- The Paris Agreement includes the goals of ‘holding the increase in the global average temperature to well below 2°C above pre-industrial levels’ and ‘making finance flows consistent with a pathway towards low greenhouse gas emissions’. Industrial energy efficiency will play an important role in meeting those goals as well as becoming a competitive advantage due to reduced costs for companies. The aluminium industry is energy intensive and uses fossil fuels both for energy purposes and as reaction material. Additionally, the aluminium industry uses significant amounts of electricity. The electrolysis process in the primary production of aluminium is the most energy- and carbon-intensive process within the aluminium industry. The aim of this paper is to study the effects on primary energy use, greenhouse gas emissions and costs when three energy efficiency measures are implemented in the electrolysis process. The effects on the primary energy use, greenhouse gas emissions and costs are calculated by multiplying the savings in final energy use by a primary energy factor, emissions factor and price of electricity, respectively. The results showed significant savings in primary energy demand, greenhouse gas emissions and cost from the implementation of the three measures. These results only indicate the size of the potential savings and a site-specific investigation needs to be conducted for each plant. This paper is a part of a research project conducted in close cooperation with the Swedish aluminium industry.
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