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Gipe, P. & Möllerström, E. (2023). An overview of the history of wind turbine development: Part II–The 1970s onward. Wind Engineering: The International Journal of Wind Power, 47(1), 220-248
Open this publication in new window or tab >>An overview of the history of wind turbine development: Part II–The 1970s onward
2023 (English)In: Wind Engineering: The International Journal of Wind Power, ISSN 0309-524X, E-ISSN 2048-402X, Vol. 47, no 1, p. 220-248Article in journal (Refereed) Published
Abstract [en]

We review the development of wind turbines for generating electricity from the late 19th century to the present, summarizing some key characteristics. We trace the move from two and four blade wind turbines to the three blades common today. We establish that it was not the governmental-funded wind programs with its large-scale prototypes of the 1970–80s that developed into the commercial turbines of today. Instead, it was the small-scale Danish wind turbines, developed for an agricultural market, that developed into the commercial turbines of today. And we show that much of what we know today about wind turbine design was known by the 1930s and certainly well known by the late 1950s. This work is divided into two parts: the first part takes up the development from the first electricity producing wind turbines through to the 1960s and a second part on development from the 1970s onward. © The Author(s) 2022.

Place, publisher, year, edition, pages
London: Sage Publications, 2023
Keywords
Wind turbine history, wind-electric generators, wind turbine design
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-48027 (URN)10.1177/0309524X221122594 (DOI)000852021100001 ()2-s2.0-85136459336 (Scopus ID)
Available from: 2022-09-08 Created: 2022-09-08 Last updated: 2023-01-12Bibliographically approved
Lind, J., Möllerström, E., Averfalk, H. & Ottermo, F. (2023). Energy flexibility using the thermal mass of residential buildings. Energy and Buildings, 301, 1-12, Article ID 113698.
Open this publication in new window or tab >>Energy flexibility using the thermal mass of residential buildings
2023 (English)In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 301, p. 1-12, article id 113698Article, review/survey (Refereed) Published
Abstract [en]

The transition to a more sustainable energy system with a growing amount of intermittent renewable energy sources brings an increasing need for flexibility measures to maintain balance between supply and demand. Buildings represent a promising source of demand-side flexibility due to their large energy demand and thermal mass. This review provides insights into the storage potential of building thermal mass, and the benefits and challenges it brings. It is found that building thermal mass storage have good ability to shift loads on short term, from peak to off-peak hours. This ability can be utilized for different purposes, for instance reduced costs for end-users or energy providers, reduced primary energy demand, or reduced CO2 emissions. Furthermore, this review explores different factors that influence the storage potential of building thermal mass, with special attention paid to the heat emission system. It is shown that hydronic floor heating is beneficial compared to radiators since it directly can activate the thermal mass with smaller impact on the indoor temperature. It is also found that the factor with largest impact is the envelope insulation level; increased insulation level brings improved storage efficiency and prolonged thermal autonomy but also decreased storage capacity and increased risk of overheating. Finally, research gaps are identified. © 2023 The Authors

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2023
Keywords
Building thermal mass (BTM), Demand-side management, Energy flexibility, Load shifting, Residential buildings, Thermal energy storage (TES)
National Category
Energy Systems Energy Engineering
Identifiers
urn:nbn:se:hh:diva-52037 (URN)10.1016/j.enbuild.2023.113698 (DOI)2-s2.0-85175613669& (Scopus ID)
Available from: 2023-11-21 Created: 2023-11-21 Last updated: 2023-11-28Bibliographically approved
Möllerström, E. & Gipe, P. (2023). The History of Wind Power. In: Reference Module in Earth Systems and Environmental Sciences: . Amsterdam: Elsevier
Open this publication in new window or tab >>The History of Wind Power
2023 (English)In: Reference Module in Earth Systems and Environmental Sciences, Amsterdam: Elsevier, 2023Chapter in book (Refereed)
Abstract [en]

Wind power received sporadic interest after the breakthrough of electricity in the late 1800s, but was sidelined by other electricity generation technologies until the 1970s. A renewed interest in alternative energy sources during the 1970s spurred the development of wind turbines, which gradually evolved into the modern large wind turbines. Whereas significant attention and financial support were focused on government-funded multi-MW prototypes, the small wind turbines developed for the Danish market in the late 1970s proved to be the template for future development.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2023
Keywords
Energy history, wind energy history, wind energy, wind power history, wind power, wind turbine history, wind turbine design
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-50256 (URN)10.1016/B978-0-323-93940-9.00004-9 (DOI)9780124095489 (ISBN)
Available from: 2023-03-30 Created: 2023-03-30 Last updated: 2023-12-08Bibliographically approved
Sánchez-García, L., Averfalk, H., Möllerström, E. & Persson, U. (2023). Understanding effective width for district heating. Energy, 277, Article ID 127427.
Open this publication in new window or tab >>Understanding effective width for district heating
2023 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 277, article id 127427Article in journal (Refereed) Published
Abstract [en]

District heating is one of the technologies that can contribute to the decarbonisation of the European heat sector. Nonetheless, these infrastructures only deliver about a tenth of the heat demands in the continent. Therefore, it is essential to assess the expansion potential of these systems and to identify which areas should be target for further investigations, which calls for easy-to-use and straightforward methods such as Persson & Werner's network capital cost model. Pivotal parameters of the model are the effective width, a metric of trench length by land area, alongside the average pipe diameter and the linear heat density. This study has carried out an in-depth analysis of these crucial parameters with respect to both distribution and service pipes in a large Danish district heating network, which has allowed to explore the behaviour of effective width in a broad range of building densities and derive new equations for both effective width and average pipe diameter. The model has subsequently been validated in another large network in Denmark and several minor districts in the same country, showing the accuracy of the model on an aggregated level. © 2023 Elsevier Ltd.

Place, publisher, year, edition, pages
London: Elsevier, 2023
Keywords
District heating, GIS, Pipe network, Cost analysis, Effective width, Plot ratio
National Category
Energy Engineering
Research subject
Smart Cities and Communities
Identifiers
urn:nbn:se:hh:diva-50424 (URN)10.1016/j.energy.2023.127427 (DOI)000992994200001 ()2-s2.0-85154565584 (Scopus ID)
Funder
EU, Horizon 2020, 846463
Available from: 2023-05-07 Created: 2023-05-07 Last updated: 2023-06-21Bibliographically approved
Gipe, P. & Möllerström, E. (2022). An overview of the history of wind turbine development: Part I — The early wind turbines until the 1960s. Wind Engineering: The International Journal of Wind Power, 46(6), 1973-2004
Open this publication in new window or tab >>An overview of the history of wind turbine development: Part I — The early wind turbines until the 1960s
2022 (English)In: Wind Engineering: The International Journal of Wind Power, ISSN 0309-524X, E-ISSN 2048-402X, Vol. 46, no 6, p. 1973-2004Article in journal (Refereed) Published
Abstract [en]

We review the development of wind turbines for generating electricity from the late 19th century to the present, summarizing some key characteristics. We trace the move from two to four blade wind turbines to the three blades common today. We establish that it was not the governmental-funded wind programs with its large-scale prototypes of the 1970–80s that developed into the commercial turbines of today. Instead it was the small-scale Danish wind turbines, developed for an agricultural market, that developed into the commercial turbines of today. And we show that much of what we know today about wind turbine design was known by the 1930s and certainly well known by the late 1950s. This work is divided into two parts: the first part takes up the development from the first electricity producing wind turbines through to the 1960s and a second part on development from the 1970s onward. © The Author(s) 2022.

Place, publisher, year, edition, pages
London: Sage Publications, 2022
Keywords
Wind turbine history, wind-electric generators, wind turbine design
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-47688 (URN)10.1177/0309524X221117825 (DOI)000840951800001 ()2-s2.0-85136026214 (Scopus ID)
Available from: 2022-08-16 Created: 2022-08-16 Last updated: 2023-02-15Bibliographically approved
Möllerström, E. (2022). Energy—History and Time Trends: Special Issue Editorial. Energies, 15(15), Article ID 5558.
Open this publication in new window or tab >>Energy—History and Time Trends: Special Issue Editorial
2022 (English)In: Energies, E-ISSN 1996-1073, Vol. 15, no 15, article id 5558Article in journal, Editorial material (Other academic) Published
Place, publisher, year, edition, pages
Basel: MDPI, 2022
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-47648 (URN)10.3390/en15155558 (DOI)000839952300001 ()2-s2.0-85136509153 (Scopus ID)
Available from: 2022-07-31 Created: 2022-07-31 Last updated: 2023-08-28Bibliographically approved
Negash, T., Möllerström, E., Ottermo, F. & Zeraebruk, K. (2022). Technical Feasibility of Large-scale Wind Energy Production in Eritrea. In: Kheira Anissa Tabet Aoul; Mohammed Tariq Shafiq; Daniel Efurosibina Attoye (Ed.), ZEMCH 2021 International Conference Proceedings: . Paper presented at 8th Zero Energy Mass Custom Home International Conference, Dubai, United Arab Emirates, 26th-28th October, 2021 (pp. 613-624). United Arab Emirates University
Open this publication in new window or tab >>Technical Feasibility of Large-scale Wind Energy Production in Eritrea
2022 (English)In: ZEMCH 2021 International Conference Proceedings / [ed] Kheira Anissa Tabet Aoul; Mohammed Tariq Shafiq; Daniel Efurosibina Attoye, United Arab Emirates University , 2022, p. 613-624Conference paper, Published paper (Refereed)
Abstract [en]

With the rapid depletion of fossil fuels and alarming environmental concerns renewable energy utilization is becoming the best option for electricity production. Moreover, renewable electricity production from wind energy has become a notable objective globally for its enormous potential and technological advancement. The main objective of this paper is to investigate the technical feasibility of large-scale wind power production in Eritrea. The study was carried-out based on two different data sources (measured and modeled) containing time-series of weather data and a third reference data from Global Wind Atlas (GWA) was used for validation purposes. The characteristics and distribution of the wind speed for all data sets were described using Weibull distribution. Two turbines (Enercon E-82 and Vestas V90) were selected to test their performance in the proposed sites. Weibull distribution - representative of the original data sets- along with the turbines’ power curves were used to determine the Annual Energy Production (AEP) and capacity factor (Cf􏰀􏰁) of the turbines. The Vestas wind turbine was found to have a better performance compared to Enercon turbine in both sites for all data sets. Furthermore, the influence of air density in AEP and 􏰀􏰁Cf was investigated and the finding showed that as much as 12% variation on AEP was obtained in Dekemhare site which is located in the highlands of Eritrea. Though the variation between the measured and modeled data sets exists in both sites, the difference in mean wind speed, power density, AEP and Cf􏰀􏰁 was more exaggerated for Dekemahre site. Referring to the measured data series both sites found to be very attractive for utility scale wind power production.

Place, publisher, year, edition, pages
United Arab Emirates University, 2022
Series
ZEMCH International Conference Proceedings, E-ISSN 2652-2926
Keywords
Wind Power, Weibull distribution, AEP, Capacity factor, Dekemhare wind site, Assab Wind site
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-46192 (URN)978-9948-31-000-6 (ISBN)
Conference
8th Zero Energy Mass Custom Home International Conference, Dubai, United Arab Emirates, 26th-28th October, 2021
Available from: 2022-01-11 Created: 2022-01-11 Last updated: 2022-01-18Bibliographically approved
Möllerström, E. & Ottermo, F. (2021). Calculational model for first-mode eigenfrequency of a semi-guy-wired vertical-axis wind turbine tower. Wind Engineering: The International Journal of Wind Power, 45(2), 205-212
Open this publication in new window or tab >>Calculational model for first-mode eigenfrequency of a semi-guy-wired vertical-axis wind turbine tower
2021 (English)In: Wind Engineering: The International Journal of Wind Power, ISSN 0309-524X, E-ISSN 2048-402X, Vol. 45, no 2, p. 205-212Article in journal (Refereed) Published
Abstract [en]

A simple model for accounting for tower mass when estimating the first-mode eigenfrequency of a semi-guy-wired tower has been derived. This extends previous work where an analytical model of the semi-guy-wired tower of a 200-kW vertical-axis wind turbine was developed. The model was primarily used to estimate the eigenfrequencies as a result of adding guy wires to a free-standing tower (thus creating a semi-guy-wired setup). However, a weakness with the model was that the tower mass was accounted for in a rough way that essentially ignored the guy wires, which gave a larger-than-necessary error. In this work, an effective top mass, that takes into account the tower mass and the constraints from the guy wires, is derived to achieve a higher accuracy when estimating the first-mode eigenfrequency. This, together with the earlier models, gives a more complete method to estimate the eigenfrequencies for a semi-guy-wired wind turbine. © The Author(s) 2019.

Place, publisher, year, edition, pages
London: Sage Publications, 2021
Keywords
Vertical-axis wind turbine, eigenfrequency, natural frequency, semi-guy-wired
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-40775 (URN)10.1177/0309524X19882433 (DOI)000491749600001 ()2-s2.0-85074440155 (Scopus ID)
Available from: 2019-10-22 Created: 2019-10-22 Last updated: 2021-05-27Bibliographically approved
Averfalk, H., Möllerström, E. & Ottermo, F. (2021). Domestic hot water design and flow measurements. Paper presented at The 17th International Symposium on District Heating and Cooling, Nottingham Trent University, 17th DHC Symposium, Nottingham, United Kingdom, 6–9 September, 2021. Energy Reports, 7(Suppl. 4), 304-310
Open this publication in new window or tab >>Domestic hot water design and flow measurements
2021 (English)In: Energy Reports, E-ISSN 2352-4847, Vol. 7, no Suppl. 4, p. 304-310Article in journal (Refereed) Published
Abstract [en]

In this study, the sizing of primary side components for preparation of domestic hot water are analysed, both qualitatively and based on measurements of domestic hot water demand in one multi-family building with 268 apartments. The collected data spans a period of 18 days during the end of 2020 and is collected in 15-min, 1-min, and 6-s intervals. An overview of the historic development for the design of domestic hot water flow in Sweden is also presented. There is a long-standing argument in Sweden, that the current district heating guidelines result in an overdesign of the flow for domestic hot water. The consequence of this is oversizing heat exchangers and valves in the substations. This study assesses, qualitatively, the issues related to overdesigned primary side valves for preparation of domestic hot water. A revised design for domestic hot water flow for the Swedish context is also conceptualised. The study suggests that an improved design flow for domestic hot water in multi-family buildings can be derived based on empirical measurements. The 15-min intervals are observed to tone down information of peaks to a degree where it is unsuitable to use as basis for a new design flow. The 1-min data does appear to preserve information to a degree where it can be used to assess a design flow when related to data with a 6-s interval. The 6-s data is expected to constitute a resolution that may be less available, and in this study, it constitutes a representation of the real domestic hot water demands. However, to find a fitted curve to empirical data, for the design flow based on number of apartments per multi-family building, the population of datasets needs to be increased. © 2021 The Authors. Published by Elsevier Ltd.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2021
Keywords
Domestic hot water, Measurements, Design flow, Multi-family building, District heating
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-45807 (URN)10.1016/j.egyr.2021.08.142 (DOI)000727834400034 ()2-s2.0-85130310848 (Scopus ID)
Conference
The 17th International Symposium on District Heating and Cooling, Nottingham Trent University, 17th DHC Symposium, Nottingham, United Kingdom, 6–9 September, 2021
Projects
Real domestic hot water flows in multi-family buildings
Note

Funding: Energiforsk (grant no. KVU63022)

Available from: 2021-10-29 Created: 2021-10-29 Last updated: 2022-06-22Bibliographically approved
Möllerström, E., Gregory, S. & Sugathan, A. (2021). Improvement of AEP Predictions with Time for Swedish Wind Farms. Energies, 14(12), Article ID 3475.
Open this publication in new window or tab >>Improvement of AEP Predictions with Time for Swedish Wind Farms
2021 (English)In: Energies, E-ISSN 1996-1073, Vol. 14, no 12, article id 3475Article in journal (Refereed) Published
Abstract [en]

Based on data from 2083 wind turbines installed in Sweden from 1988 onwards, the accuracy of the predictions of the annual energy production (AEP) from the project planning phases has been compared to the actual wind-index-corrected production. Both the electricity production and the predicted AEP come from Vindstat, a database that collects information directly from wind turbine owners. The mean error for all analyzed wind turbines was 13.0%, which means that, overall, the predicted AEP has been overestimated. There has been an improvement of accuracy with time with an overestimation of 8.2% for wind turbines installed in the 2010s, however, the continuous improvement seems to have stagnated around 2005 despite better data availability and continuous refinement of methods. Dividing the results by terrain, the error is larger for wind turbines in open and flat terrain than in forest areas, indicating that the reason behind the error is not the higher complexity of the forest terrain. Also, there is no apparent increase of error with wind farm size which could have been expected if wind farm blockage effect was a main reason for the overestimations. Besides inaccurate AEP predictions, a higher-than-expected performance decline due to inadequate maintenance of the wind turbines may be a reason behind the AEP overestimations. The main sources of error are insecurity regarding the source of AEP predictions and the omission of mid-life alterations of rated power. © 2021 by the authors.

Place, publisher, year, edition, pages
Basel: MDPI, 2021
Keywords
energy assessment, Vindstat, AEP, WCP, wind power, Sweden
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-44669 (URN)10.3390/en14123475 (DOI)000665974200001 ()2-s2.0-85108427763 (Scopus ID)
Available from: 2021-06-12 Created: 2021-06-12 Last updated: 2023-08-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9982-5317

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