| 1. |
- Brännvall, Rickard, et al.
(författare)
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Data center excess heat recovery : A case study of apple drying
- 2020
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Ingår i: ECOS 2020 - Proceedings of the 33rd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - : ECOS 2020 Local Organizing Committee. ; , s. 2165-2174, s. 2165-2174
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Konferensbidrag (refereegranskat)abstract
- Finding synergies between heat producing and heat consuming actors in an economy provides opportunity for more efficient energy utilization and reduction of overall power consumption. We propose to use low-grade heat recovered from data centers directly in food processing industries, for example for the drying of fruit and berries. This study analyses how the heat output of industrial IT-load on servers can dry apples in a small-scale experimental set up. To keep the temperatures of the server exhaust airflow near a desired set-point we use a model predictive controller (MPC) re-purposed to the drying experiment set-up from a previous work that used machine learning models for cluster thermal management. Thus, conditions with for example 37 C for 8 hours drying can be obtained with results very similar to conventional drying of apples. The proposed solution increases the value output of the electricity used in a data center by capturing and using the excess heat that would otherwise be exhausted. The results from our experiments show that drying foods with excess heat from data center is possible with potential of strengthening the food processing industry and contribute to food self-sufficiency in northern Sweden.
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| 2. |
- Brännvall, Rickard, et al.
(författare)
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EDGE : Microgrid Data Center with Mixed Energy Storage
- 2020
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Ingår i: e-Energy 2020 - Proceedings of the 11th ACM International Conference on Future Energy Systems. - New York, NY, USA : Association for Computing Machinery, Inc. - 9781450380096 ; , s. 466-473, s. 466-473
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Konferensbidrag (refereegranskat)abstract
- Low latency requirements are expected to increase with 5G telecommunications driving data and compute to EDGE data centers located in cities near to end users. This article presents a testbed for such data centers that has been built at RISE ICE Datacenter in northern Sweden in order to perform full stack experiments on load balancing, cooling, micro-grid interactions and the use of renewable energy sources. This system is described with details on both hardware components and software implementations used for data collection and control. A use case for off-grid operation is presented to demonstrate how the test lab can be used for experiments on edge data center design, control and autonomous operation. © 2020 Author.
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| 3. |
- Galkin, Nikolai, et al.
(författare)
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On Modelling of Edge Datacentre Microgrid for Participation in Smart Energy Infrastructures
- 2022
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Ingår i: IEEE Open Journal of the Industrial Electronics Society. - : Institute of Electrical and Electronics Engineers Inc.. - 2644-1284. ; 3, s. 50-64
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Tidskriftsartikel (refereegranskat)abstract
- Datacentres are becoming a sizable part of the energy system and are one of the biggest consumers of the energy grid. The so-called “Green Datacentre” is capable of not only consuming but also producing power, thus becoming an important kind of prosumers in the electric grid. Green datacentres consist of a microgrid with a backup uninterrupted power supply and renewable generation, e.g., using photovoltaic panels. As such, datacentres could realistically be important participants in demand/response applications. However, this requires reconsidering their currently rigid control and automation systems and the use of simulation models for online estimation of the control actions impact. This paper presents such a microgrid simulation model modelled after a real edge datacentre. A case study consumption scenario is presented for the purpose of validating the developed microgrid model against data traces collected from the green edge datacentre. Both simulation and real-time validation tests are performed to validate the accuracy of the datacentre model. Then the model is connected to the automation environment to be used for the online impact estimation and virtual commissioning purposes.
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| 4. |
- Johansson, Tim, et al.
(författare)
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Energy performance certificates and 3-dimensional city models as a means to reach national targets : A case study of the city of Kiruna
- 2016
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 116, s. 42-57
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Tidskriftsartikel (refereegranskat)abstract
- Enhanced dissemination of information regarding energy saving and climate change targeted toward property owners is considered to be an important strategy in order to reach the Swedish national target of energy efficiency in the building sector by 2050. Here the municipality energy advisors and the national register for energy performance certificates can facilitate the mitigation of energy use in the building stock. So far few studies have focused on the practical road map to the national target of energy use on the city/district level and to the communication aspects with stakeholders in the creation of energy city models.In this paper a city energy model is developed based on the requests and need for visualization from a group of energy advisors. Six different scenarios are studied in order to analyze the possibility of reaching the energy targets specified by the government in the town of Kiruna. The results show that: (1) it is possible to automatically create city energy models using extract, transform and load tools based on spatial and non-spatial data from national registers and databases; (2) city energy models improve the understanding of energy use in buildings and can therefore be a valuable tool for energy advisors, real estate companies and urban planners. The case study of Kiruna showed that the proposed energy saving measures in the energy performance certificates need to be implemented and new buildings in the urban transformation must be of high energy standard in order to reach the national target in Kiruna.
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| 5. |
- Markeby Ljungqvist, Hampus, et al.
(författare)
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A realistic view on heat reuse from direct free air-cooled data centres
- 2023
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Ingår i: Energy Conversion and Management. - : Elsevier. - 2590-1745. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines the opportunities to reuse excess heat from direct free air-cooled data centres without incorporating heat pumps to upgrade the heat. The operation of a data centre in northern Sweden, Luleå, was simulated for a year. It was established that heat losses through the thermal envelope and from the humidification of the cooling airflow influenced the momentary energy reuse factor, iERF, with up to 7%. However, for the annual energy reuse factor, ERF, the heat losses could be neglected since they annually contributed to an error of less than 1%. It was shown that the ideal heat reuse temperature in Luleå was 13, 17, and 18 °C with an exhaust temperature of 30, 40 and 50 °C. The resulting ERF was 0.50, 0.59 and 0.66, meaning that a higher exhaust temperature resulted in potentially higher heat reuse. It could also be seen that raising the exhaust temperature lowered the power usage effectiveness, PUE, due to more efficient cooling. Using heat reuse applications with different heat reuse temperatures closer to the monthly average instead of an ideal heat reuse temperature for the whole year improved the ERF further. The improvement was 11–31% where a lower exhaust temperature meant a higher relative improvement.
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| 6. |
- Markeby Ljungqvist, Hampus, et al.
(författare)
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Data center heated greenhouses, a matter for enhanced food self-sufficiency in sub-arctic regions
- 2021
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Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 215
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines the possibility of increasing Northern Sweden's degree of self-sufficiency in food supply, at the 65th latitude, by using a data center as a heating source for greenhouse production. A dynamic building energy simulation software was used to compute both the hourly exhaust air output from a 1 MW data center for one year and the corresponding heating demand for two different greenhouse sizes, 2000 m2 and 10 000 m2, and two different production scenarios. Partial year production, 1 Mars – 15 October, without grow lights and full-year production with grow lights. The study showed that 5.5–30.5% of the electrical input to a 1 MW data center could be recovered. The 2000 m2 greenhouse could operate almost entirely, 89.7–97.9%, on excess heat while only 50.0–61.5% of the 10 000 m2 greenhouse heating demand could be met for full- and partial-year production, respectively. Furthermore, it is concluded that the 10 000 m2 greenhouse with full year production was the most prominent case and would cost-effectively yield 7.6% of northern Sweden's vegetable self-sufficiency.
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| 7. |
- Pericault, Youen, 1992-, et al.
(författare)
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A novel freeze protection strategy for shallow buried sewer pipes : temperature modelling and field investigation
- 2016
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Ingår i: Proceedings of the 8th International Conference on Sewer Processes & Networks.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The burial of sewer and water pipes below the maximum ground frost depth can be very costly and laborious in regions with cold winters. If a freeze protection measure is applied, the utility lines can be installed in a shallower trench to reduce the excavation needs during construction and maintenance works. One freeze protection measure, so called heat tracing, consist in supplying heat along the pipes. In this work, the use of 4th generation district heating as a heat tracing solution was investigated at a pilot site in Kiruna, Sweden. The influence of the system on sewer and water pipes temperatures was studied experimentally and numerically at a snow-free and snow-covered cross section. The study showed that, under the climatic conditions of the experiment, a heat tracing temperature of 25 ˚C allowed to prevent freezing of the pipes while keeping drinking water pipes in safe temperature range at both cross sections. The other main result was that a finite volume model of the sections was developed and showed a good fitting to the experimental data.
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| 8. |
- Pericault, Youen, 1992-, et al.
(författare)
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A novel freeze protection strategy for shallow buried sewer pipes : temperature modelling and field investigation
- 2017
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 76:2, s. 294-301
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Tidskriftsartikel (refereegranskat)abstract
- The burial of sewer and water pipes below the maximum ground frost depth can be very costly and laborious in regions with cold winters. If a freeze protection measure is applied, the utility lines can be installed in a shallower trench to reduce the excavation needs. One freeze protection measure, so called heat tracing, consists in supplying heat along the pipes. In this work, the use of 4th generation district heating as a heat tracing solution was investigated at a pilot site in Kiruna, Sweden. The influence of the system on sewer and water pipe temperatures was studied at a snow-free and snow-covered cross section. To this end, five heat tracing temperatures were tested and the corresponding sewer and water pipe temperatures were measured. The field experiment was also simulated with a two dimensional finite volume model. The study showed that, under the climatic conditions of the experiment, a heat tracing temperature of 25 °C allowed to prevent freezing of the pipes while keeping drinking water pipes in a safe temperature range at both cross sections. The other main result was that the developed finite volume model of the sections showed a good fitting to the experimental data
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| 9. |
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| 10. |
- Ramos Caceres, Cristina, et al.
(författare)
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Data-Center Farming: Exploring the Potential of Industrial Symbiosis in a Subarctic Region
- 2022
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 14:5
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Tidskriftsartikel (refereegranskat)abstract
- As our world becomes increasingly digitalized, data centers as operational bases for these technologies lead to a consequent increased release of excess heat into the surrounding environment. This paper studies the challenges and opportunities of industrial symbiosis between data centers’ excess heat and greenhouse farming, specifically utilizing the north of Sweden as a case study region. The region was selected in a bid to tackle the urgent urban issue of self-sufficiency in local food production. A synergetic approach towards engaging stakeholders from different sectors is presented through a mix of qualitative and quantitative methods to facilitate resilient data-center-enabled food production. The paper delivers on possible future solutions on implementing resource efficiency in subarctic regions.
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