| 1. |
- Lehtveer, Mariliis, 1983, et al.
(författare)
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Actuating the European Energy System Transition: Indicators for Translating Energy Systems Modelling Results into Policy-Making
- 2021
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Ingår i: Frontiers in Energy Research. - : Frontiers Media SA. - 2296-598X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we define indicators, with a focus on the electricity sector, that translate the results of energy systems modelling to quantitative entities that can facilitate assessments of the transitions required to meet stringent climate targets. Such indicators, which are often overlooked in model scenario presentations, can be applied to make the modelling results more accessible and are useful for managing the transition on the policy level, as well as for internal evaluations of modelling results. We propose a set of 13 indicators related to: 1) the resource and material usages in modelled energy system designs; 2) the rates of transition from current to future energy systems; and 3) the energy security in energy system modelling results. To illustrate its value, the proposed set of indicators is applied to energy system scenarios derived from an electricity system investment model for Northern Europe. We show that the proposed indicators are useful for facilitating discussions, raising new questions, and relating the modelling results to Sustainable Development Goals and thus facilitate better policy processes. The indicators presented here should not be seen as a complete set, but rather as examples. Therefore, this paper represents a starting point and a call to other modellers to expand and refine the list of indicators.
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| 2. |
- Romanchenko, Dmytro, 1988, et al.
(författare)
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Balancing investments in building energy conservation measures with investments in district heating – A Swedish case study
- 2020
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 226
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the cost-optimal mix of reduction in the space heating (SH) demand in buildings, achieved through investments in energy conservation measures (ECMs), and investments in the local district heating (DH) system. The work includes three modeling scenarios, which differ with respect to SH demand reduction targets (no supply side targets) for buildings: without a target (only fuel price drives demand reduction); with a total demand reduction (for the building stock); and with a specific demand reduction (to reach a specific kWh/(m2∙y) value for individual buildings). Special emphasis is placed on the choice of ECMs in buildings. For the scenario without a target for SH demand reduction, the least-cost option is a combination of investments in ECMs, heat generation and in storage technologies, yielding a SH demand reduction of 24% already by Year 2030, and thereafter a decrease of 28% up to Year 2050. The reductions are achieved mainly through investments in ventilation heat recovery systems and insulation of roofs. The scenarios that include SH demand reduction targets give similar demand reductions of about 60% by 2050, as compared to 2020. However, the investment cost for fulfilling the specific target scenario is higher than that for the total target scenario.
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| 3. |
- Romanchenko, Dmytro, 1988, et al.
(författare)
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Flexibility Potential of Space Heating Demand Response in Buildings for District Heating Systems
- 2019
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Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 12:15
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Tidskriftsartikel (refereegranskat)abstract
- Using an integrated demand-supply optimization model, this work investigates the potential for flexible space heating demand, i.e., demand response (DR), in buildings, as well as its effects on the heating demand and the operation of a district heating (DH) system. The work applies a building stock description, including both residential and non-residential buildings, and employs a representation of the current DH system of the city of Gothenburg, Sweden as a case study. The results indicate that space heating DR in buildings can have a significant impact on the cost-optimal heat supply of the city by smoothing variations in the system heat demand. DR implemented via indoor temperature deviations of as little as +1 degrees C can smoothen the short-term (daily) fluctuations in the system heating demand by up to 18% over a period of 1 year. The smoothening of the demand reduces the cost of heat generation, in that the heat supply and number of full-load hours of base-load heat generation units increase, while the number of starts for the peaking units decreases by more than 80%. DR through temperature deviations of +3 degrees C confers diminishing returns in terms of its effects on the heat demand, as compared to the DR via +1 degrees C.
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| 4. |
- Romanchenko, Dmytro, 1988, et al.
(författare)
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Impact of electricity price fluctuations on the operation of district heating systems: A case study of district heating in Göteborg, Sweden
- 2017
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 204, s. 16-30
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Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the characteristics of interaction between district heating (DH) systems and the electricity system, induced by present and future price curves of the electricity system. A mixed integer linear programming unit commitment model has been developed with the objective of studying optimal operating strategies for DH systems. The model minimises the total operating cost of heat generation for a given DH system, which in this work is exemplified by the DH system of Göteborg, Sweden. The results should have important implications for operating strategies for DH systems as a response to future electricity price development. The results indicate significant changes in the operation of heat generation units in DH systems as a response to future electricity price profile with a, relative to today, high yearly average electricity price and more frequent high-electricity-price periods. The observed changes include a 20% decrease in heat generation from heat pumps (HP) and an increase of up to 25% in heat generation from combined heat and power (CHP) plants, owing to a switch in the merit order of these two technologies. We show that large fluctuations in the electricity price lead to an increased value being placed on CHP plants with variable power-to-heat ratio. The results indicate that with reoccurring high-electricity-price periods the value of sold electricity alone can become high enough to motivate investment in CHP plants, i.e. indicating that the generation and selling of heat from CHP plants may not be the core business in the future. Furthermore, there are additional opportunities for increased value of both CHP plants and HPs for time periods of less than 48 h, given that such short duration periods can be identified in a reasonable time in advance, i.e. dependent on, for instance, wind power forecasts.
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| 5. |
- Romanchenko, Dmytro, 1988, et al.
(författare)
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Impacts of demand response from buildings and centralized thermal energy storage on district heating systems
- 2021
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Ingår i: Sustainable Cities and Society. - : Elsevier BV. - 2210-6707. ; 64
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Tidskriftsartikel (refereegranskat)abstract
- © 2020 The Author(s) Energy use for space heating is a substantial part of total energy end use and heating systems can offer some flexibility in time of use, which should be important in future energy systems to maintain balance between supply and demand. This work applies a techno-economic, integrated, demand-supply optimization model to investigate the combined effect of using demand-side flexibility from buildings, by allowing for indoor temperature deviations (both up- and downward from the set-point), and supply-side flexibility, by applying thermal energy storage (TES), on the operation of district heating (DH) systems. The results indicate that the potential for increased indoor temperature, i.e., demand response (DR), is concentrated to multi-family and non-residential buildings (heavy buildings with high time-constants), while the potential for downregulation of the temperature, i.e., operational energy savings, is utilized to a greater extent by single-family buildings (light buildings). It is also evident that the value of DR diminishes in the presence of a supply-side TES. We show that applying both the demand-side flexibility and a centralized TES is complementary from the heating system perspective in that it results in the lowest total space heating load of the buildings and the lowest running cost for the DH system.
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| 6. |
- Romanchenko, Dmytro, 1988, et al.
(författare)
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Thermal energy storage in district heating: Centralised storage vs. storage in thermal inertia of buildings
- 2018
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904. ; 162, s. 26-38
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Tidskriftsartikel (refereegranskat)abstract
- Heat load variations in district heating systems lead to increased costs for heat generation and, in most cases, increased greenhouse gas emissions associated with the marginal use of fossil fuels. This work investigates the benefits of applying thermal energy storage in district heating systems to decrease heat load variations, comparing storage using a hot water tank and the thermal inertia of buildings (with similar storage capacity). A detailed techno-economic optimisation model is applied to the district heating system of Göteborg, Sweden. The results show that both the hot water tank and the thermal inertia of buildings benefit the operation of the district heating system and have similar dynamics of utilisation. However, compared to the thermal inertia of buildings, the hot water tank stores more than twice as much heat over the modelled year, owing to lower energy losses. For the same reason, only the hot water tank is used to store heat for periods longer than a few days. Furthermore, the hot water tank has its full capacity available for charging/discharging at all times, whereas the capacity of the thermal inertia of buildings depends on the heat transfer between the building core and its indoor air and internals. Finally, the total system yearly operating cost decreases by 1% when the thermal inertia of buildings and by 2% when the hot water tank is added to the district heating system, as compared to the scenario without any storage.
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