| 1. |
- Brett, Nancy, 1974-
(författare)
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Bridging Local Constraints and Global Priorities : The Shaping of Swedish Biogas Markets
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biogas offers a sustainable alternative to fossil fuels, promoting circularity and local economic growth. It is, therefore, increasingly prioritised by decision-makers within Sweden and the EU. Despite its advantages, the Swedish market is perceived as underachieving in terms of scale and penetration. Biogas, a socio-technical system, has necessitated state and regional support for its establishment and expansion, given its competition with entrenched fossil fuels and its inherent material limitations. This thesis primarily seeks to explore how the interplay of political, societal, and market perspectives has influenced the biogas market. The research zeroes in on the Swedish biogas market, with a special focus on the impact of geographical regions on market shaping. Using in part a longitudinal case study revealed that historically, successful regions have relied heavily on translations of missions and visions for developing the biogas markets. These translations were found to build heavily on local concerns and local resources. The consequence of this meant that the global context of the climate problem was not always the focus of policy and strategies. The significance of local interpretation was further unveiled as a component of value creation, where value is closely tied to the material and social conditions of local geographies. Value creation for intricate systems like biogas, which are multifunctional and span various social domains, indicates that biogas and biofertilisers are entities that are both naturally and socially constructed, underlining the impossibility of separating the natural from the social. The socio-material properties were important for biogas market shaping, as shown by tracing both biogas and biofertilisers. The connections between methane and fossil gas were found to be positive and negative for the biogas market. The reliance on fossil gas has created conditions that allow the biogas market to expand. However, the narrative of fossil gas as a bridge has, at times, led to doubts about biogas, and there is a risk that instead of biogas greening fossil gas, fossil gas has a ‘browning’ effect on the biogas market. For biofertiliser, the socio-material was found to be in a phase of change. It was found that the biogas market has been built for the energy market, but increasingly, it is important to consider the role of biofertiliser in this market. What was previously considered to be a by-product and a problem for the producers, is increasingly seen as an asset. Similar to the findings of the connection between fossil gas and biomethane, this is a change in social framings more than a change in the material. The movement from waste to by-product to an asset can be an important view both empirically and theoretically to foreground that for an object to be understood as valuable or sustainable, work is needed. This highlighted that markets do not simply appear, and objects are not inherently valuable or sustainable. It is instead an interplay between the social, material, and technical, which (re)shapes products and their markets. Lastly, this thesis, through the lens of marketisation, traced the concerns of the bio-gas market. It found that the biogas market is still evolving often referred to as a hot market. The boundaries of the market, including what is considered an externality, are still being defined. While this doesn’t fully account for the slow growth, it does enable stakeholders to use this understanding to influence the market’s development. As the biogas market changes, along with other factors such as the role of fossil gas, the impact of material changes with liquified biogas, and the growth of the concentrated biofertiliser market, it’s evident that the narratives will shift. This thesis adds to the empirical literature on renewable energy by emphasising that regions that depend on creating value for their citizens by promoting a local narrative will need to adapt to reflect the new material realities. This will influence both how valuation processes are conducted and the use of missions and visions by both the public and private sectors.
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| 2. |
- Carlander, Jakob, et al.
(författare)
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Integration of measurements and time diaries as complementary measures to improve resolution of BES
- 2019
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Ingår i: Energies. - Basel : MDPI. - 1996-1073. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- Building energy simulation (BES) models rely on a variety of different input data, and the more accurate the input data are, the more accurate the model will be in predicting energy use. The objective of this paper is to show a method for obtaining higher accuracy in building energy simulations of existing buildings by combining time diaries with data from logged measurements, and also to show that more variety is needed in template values of user input data in different kinds of buildings. The case studied in this article is a retirement home in Linköping, Sweden. Results from time diaries and interviews were combined with logged measurements of electricity, temperature, and CO2 levels to create detailed occupant behavior schedules for use in BES models. Two BES models were compared, one with highly detailed schedules of occupancy, electricity use, and airing, and one using standardized input data of occupant behavior. The largest differences between the models could be seen in energy losses due to airing and in household electricity use, where the one with standardized user input data had a higher amount of electricity use and less losses due to airing of 39% and 99%, respectively. Time diaries and interviews, together with logged measurements, can be great tools to detect behavior that affects energy use in buildings. They can also be used to create detailed schedules and behavioral models, and to help develop standardized user input data for more types of buildings. This will help improve the accuracy of BES models so the energy efficiency gap can be reduced.
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| 3. |
- Difs, Kristina, et al.
(författare)
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Biomass gasification opportunities in a district heating system
- 2010
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Ingår i: Biomass and Bioenergy. - : Elsevier Science B.V., Amsterdam.. - 0961-9534 .- 1873-2909. ; 34:5, s. 637-651
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Tidskriftsartikel (refereegranskat)abstract
- This paper evaluates the economic effects and the potential for reduced CO2 emissions when biomass gasification applications are introduced in a Swedish district heating (DH) system. The gasification applications included in the study deliver heat to the DH network while producing renewable electricity or biofuels. Gasification applications included are: external superheater for steam from waste incineration (waste boost, WE), gas engine CHP (BIGGE), combined cycle CHP (BIGCC) and production of synthetic natural gas (SNG) for use as transportation fuel. Six scenarios are used, employing two time perspectives - short-term and medium-term - and differing in economic input data, investment options and technical system. To evaluate the economic performance an optimisation model is used to identify the most profitable alternatives regarding investments and plant operation while meeting the DH demand. This study shows that introducing biomass gasification in the DH system will lead to economic benefits for the DH supplier as well as reduce global CO2 emissions. Biomass gasification significantly increases the potential for production of high value products (electricity or SNG) in the DH system. However, which form of investment that is most profitable is shown to be highly dependent on the level of policy instruments for biofuels and renewable electricity. Biomass gasification applications can thus be interesting for DH suppliers in the future, and may be a vital measure to reach the 2020 targets for greenhouse gases and renewable energy, given continued technology development and long-term policy instruments.
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| 4. |
- Difs, Kristina
(författare)
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District Heating and CHP : Local Possibilities for Global Climate Change Mitigation
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Global warming, in combination with increasing energy demand and higher energy prices, makes it necessary to change the energy use. To secure the energy supply and to develop sustainable societies, construction of energy-efficient systems is at the same time most vital. The aim of this thesis is therefore to identify how a local energy company, producing district heating (DH), district cooling (DC) and electricity in combined heat and power (CHP) plants, can contribute to resource-efficient energy systems and cost-effective reductions of global carbon dioxide (CO2) emissions, along with its customers. Analyses have been performed on how a local energy company can optimise their DH and DC production and what supply-side and demand-side measures can lead to energy-efficient systems in combination with economic and climate change benefits. The energy company in focus is located in Linköping, Sweden. Optimisation models, such as MODEST and reMIND, have been used for analysing the energy systems. Scenario and sensitivity analyses have also been performed for evaluation of the robustness of the energy systems studied. For all analyses a European energy system perspective was applied, where a fully deregulated European electricity market with no bottlenecks or other system failures was assumed.In this thesis it is concluded that of the DH-supply technologies studied, the biomass gasification applications and the natural gas combined cycle (NGCC) CHP are the technologies with the largest global CO2 reduction potential, while the biomass-fuelled plant that only produces heat is the investment with the smallest global CO2 reduction and savings potential. However, the global CO2 reduction potential for the biomass integrated gasification combined cycle (BIGCC) CHP and NGCC CHP, the two technologies with highest electricity efficiencies, is highly dependent on the assumptions made about marginal European electricity production. Regarding the effect on the DH system cost the gasification application integrated with production of renewable biofuels (SNG) for the transport sector is the investment option with the largest savings potential for lower electricity prices, while with increasing electricity prices the BIGCC and NGCC CHP plants are the most cost-effective investment options. The economic outcome for biomass gasification applications is, however, dependent on the level of policy instruments for biofuels and renewable electricity. Moreover, it was shown that the tradable green certificates for renewable electricity can, when applied to DH systems, contribute to investments that will not fully utilise the DH systems’ potential for global CO2 emissions reductions.Also illustrated is that conversion of industrial processes, utilising electricity and fossil fuels, to DH and DC can contribute to energy savings. Since DH is mainly used for space heating, the heat demand for DH systems is strongly outdoor temperature-dependent. By converting industrial processes, where the heat demand is often dependent on process hours instead of outdoor temperature, the heat loads in DH systems can become more evenly distributed over the year, with increased base-load heat demand and increased electricity generation in CHP plants as an outcome. This extra electricity production, in combination with the freed electricity when converting electricity-using processes to DH, can replace marginal electricity production in the European electricity market, resulting in reduced global CO2 emissions.Demonstrated in this thesis is that the local energy company, along with its customers, can contribute to reaching the European Union’s targets of reducing energy use and decreasing CO2 emissions. This can be achieved in a manner that is cost-effective to both the local energy company and the customers.
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| 5. |
- Difs, Kristina, et al.
(författare)
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Energy conservation measures in buildings heated by district heating - A local energy system perspective
- 2010
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Ingår i: Energy. - : Elsevier Science B.V., Amsterdam.. - 0360-5442 .- 1873-6785. ; 35:8, s. 3194-3203
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Tidskriftsartikel (refereegranskat)abstract
- The extensive energy use in the European building sector creates opportunities for implementing energy conservation measures (ECMs) in residential buildings. If ECM are implemented in buildings that are connected to a district heating (DH) system, the operation of DH plants may be affected, which in turn may change both revenue and electricity production in cogeneration plants. In this study a local energy system, containing a DH supplier and its customer, has been analysed when implementing three ECMs: heat load control, attic insulation and electricity savings. This study is unique since it analyses economic and CO2 impacts of the ECMs in both a user and a supplier perspective in combination with a deregulated European electricity market. Results show that for the local energy system electricity savings should be prioritised over a reduction in DH use, both from an economic and a global CO2 perspective. For the DH supplier attic insulation demonstrates unprofitable results, even though this measure affects the expensive peak load boilers most. Heat load control is however financially beneficial for both the DH supplier and the residences. Furthermore, the relation between the fixed and variable DH costs is highlighted as a key factor for the profitability of the ECMs.
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| 6. |
- Difs, Kristina, 1977-, et al.
(författare)
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Increased industrial district heating use in a CHP system : economic consequences and impact on global CO2 emissions
- 2009
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Ingår i: 5th European Conference on Economics and Management of Energy in Industry.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of district heating (DH) in industrial processes is relatively limited compared to other fuels and electricity. Hence, the industrial sector has great potential to convert from electricity and fossil fuels to DH. In addition, DH is mainly used for space heating and hot tap water, which makes the DH demand strongly seasonally dependent. By converting industrial processes like cooling, drying and industrial heating to DH, the heat load curve will be more evenly distributed throughout the year, thus utilizing the DH production resources better. This paper analyses how conversions from electricity or other fuels to district heating (DH) in industrial processes will affect an energy system. The effect of a more evenly distributed heat load profile is analysed with different policy instruments, fuel prices and electricity prices. In this study, three CHP plants acting as base load plants, which utilize different fuels (biofuel, waste and natural gas), are analysed. The result shows that when the use of district heating in industrial processes is increased it will lead to reduced system cost in both the biofueled and waste-incinerated combined heat and power system. Furthermore, when considering European electricity production in coal condensing and natural gas power plants, conversion to DH will also lead to possible reduced global CO2 emissions.
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| 7. |
- Difs, Kristina, et al.
(författare)
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Increased use of district heating in industrial processes - Impacts on heat load duration
- 2009
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 86:11, s. 2327-2334
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Tidskriftsartikel (refereegranskat)abstract
- Current knowledge of the potential for an increased use of industrial district heating (DH) due to conversions of industrial processes to DH is limited. In this paper, a Method for Heat Load Analysis (MeHLA) for exploring industrial DH conversions has been developed. This method can be a helpful tool for analyzing the impact different industrial processes have on the local DH system, when processes that utilize electricity and other fuels, convert to utilizing DH instead. Heat loads for different types of industries and processes are analyzed according to characteristics such as temperature levels and time dependency. MeHLA has been used to analyze 34 Swedish industries and the method demonstrates how conversion of industrial processes to DH can result in heat load duration curves that are less outdoor temperature-dependent and more evenly distributed over the year. An evenly distributed heat load curve can result in increased annual operating time for base load DH plants such as cogeneration plants, leading to increased electricity generation. In addition to the positive effects for the DH load duration curve, the conversions to DH can also lead to an 11% reduction in the use of electricity, a 40% reduction in the use of fossil fuels and a total energy end-use saving of 6% in the industries. Converting the industrial processes to DH will also lead to a potential reduction of the global carbon dioxide emissions by 112,000 tonnes per year.
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| 8. |
- Difs, Kristina, et al.
(författare)
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Pricing district heating by marginal cost
- 2009
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Ingår i: ENERGY POLICY. - : Elsevier BV. - 0301-4215. ; 37:2, s. 606-616
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Tidskriftsartikel (refereegranskat)abstract
- A vital measure for industries when redirecting the energy systems towards sustainability is conversion from electricity to district heating (DH). This conversion can be achieved for example, by replacing electrical heating with DH and compression cooling with heat-driven absorption cooling. Conversion to DH must, however, always be an economically attractive choice for an industry. In this paper the effects for industries and the local DH supplier are analysed when pricing DH by marginal cost in combination with industrial energy efficiency measures. Energy audits have shown that the analysed industries can reduce their annual electricity use by 30% and increase the use of DH by 56%. When marginal costs are applied as DH tariffs and the industrial energy efficiency measures are implemented, the industrial energy costs can be reduced by 17%. When implementing the industrial energy efficiency measures and also considering a utility investment in the local energy system, the local DH supplier has a potential to reduce the total energy system cost by 1.6 million EUR. Global carbon dioxide emissions can be reduced by 25,000 tonnes if the industrial energy efficiency measures are implemented and when coal-condensing power is assumed to be the marginal electricity source.
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| 9. |
- Farhangi, Mosen, et al.
(författare)
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Planning Education and Transformative Capacity for Climate-Neutral Cities
- 2023
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Ingår i: Journal of planning education and research. - : SAGE PUBLICATIONS INC. - 0739-456X .- 1552-6577.
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Tidskriftsartikel (refereegranskat)abstract
- To achieve their goal to become climate neutral, Swedish municipalities must significantly improve their transformative capacities. Adapting the roles and practices of urban planners is an important element in this process. This paper critically reflects on the way in which improved planning education may help to enable a new generation of planners to face the challenges of rapid urban transformation and provides them with the knowledge and tools needed for these new roles. The results suggest that there are interdependencies between the demand of municipalities for knowledge and skills and the capacity of educational programs for educating planners with transformative abilities.
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| 10. |
- Feiz, Roozbeh, 1975-, et al.
(författare)
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Biogas Potential for Improved Sustainability in Guangzhou, China : A Study Focusing on Food Waste on Xiaoguwei Island
- 2019
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- As a result of rapid development in China and the growth of megacities, large amounts of organic wastes are generated within relatively small areas. Part of these wastes can be used to produce biogas, not only to reduce waste-related problems, but also to provide renewable energy, recycle nutrients, and lower greenhouse gases and air polluting emissions. This article is focused on the conditions for biogas solutions in Guangzhou. It is based on a transdisciplinary project that integrates several approaches, for example, literature studies and lab analysis of food waste to estimate the food waste potential, interviews to learn about the socio-technical context and conditions, and life-cycle assessment to investigate the performance of different waste management scenarios involving biogas production. Xiaoguwei Island, with a population of about 250,000 people, was chosen as the area of study. The results show that there are significant food waste potentials on the island, and that all studied scenarios could contribute to a net reduction of greenhouse gas emissions. Several socio-technical barriers were identified, but it is expected that the forthcoming regulatory changes help to overcome some of them.
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