Abstract PhD project

Modelling and optimization of the North Sea region's energy system in the long term, by Juan Gea Bermudez

The PhD project: background and motivation 

Deep decarbonisation of the energy system is required to reduce the impacts of climate change [1]. This implies replacing generation from polluting technologies with clean ones, such as variable renewables [1]. Integrating a high share of variable renewables such as wind and solar energy sets new requirements to balance the energy system in accordance with the depletion of current flexible ramping capabilities of the energy system, such as gas turbines [2]. Frameworks and market designs have to be reformulated in order to enable and promote new flexibility options that assure a high-quality security of supply in energy systems, including additional market couplings, storage and active participation of renewable energy sources at the different power markets [2][3][4][5]. One crucial aspect is the transmission infrastructure, where significant investments are foreseen and where an offshore meshed grid seems to be a more cost-efficient option for the future than the traditional radial grid [6][7][8][9], although for it to become real there is need for great international cooperation efforts [10][11][12]. Due to the complexity and the size of the energy system, the use of comprehensive mathematical tools is critical to optimize and analyse the role that each participant of the energy system has in a future energy system, as well as the market rules that would affect their behaviour and investment decisions [12]. 

The 3-year PhD project is part of two research projects: NSON-DK (North Sea Offshore Development) and Flex4RES (Flexibility for Variable Renewable Energy Integration in the Nordic Energy Systems). The objective of NSON-DK is to study how the future massive offshore wind power and the associated offshore grid development will affect the Danish power system on short term, medium term and long term towards a future sustainable energy system, whereas Flex4RES aims to assess how to integrate and consolidate different energy markets to make a solid base to anchor resilient, sustainable, cost-efficient and coherent Nordic energy systems in 2050. This PhD will contribute to achieving the objectives of both projects. 

Research objective

The PhD scholarship focuses on energy policy and market analysis, and modelling of flexible energy systems with rapidly growing shares of offshore wind in the North Sea region. The main research objective of this PhD is to answer the following research question: What is the optimal long term development of the generation, storage, and grid investments in the North Sea that ensures adequacy of the system and minimizes balancing costs?

Research areas 

 In order to answer the research objective presented above, the PhD student will work on the following research areas: 

1. Investments optimization of the long term energy system

Working on research area 1 will consist of improving the existing methodology for modelling of variable renewables including massive offshore wind power with possibility to connect to a meshed offshore grid, storage, demand flexibility and sector coupling, focusing on the North Sea region. This work will be applied to find the optimal development of generation, storage, and grid investments in the North Sea. The Balmorel energy system model will be used for this purpose [13], and it will be further developed with respect to model structure, data and code to model adequately the elements and participants involved in the energy system that will be investigated in this PhD. Extensive work is foreseen regarding data collection and processing. Under this research area, the importance of geographical, time, and technology resolution, grid representation, offshore grid architecture (traditional radial vs meshed grid), and possible cost-sharing mechanisms will be also investigated. The first paper I intend to carry on will focus on generation and transmission investment optimization. After this, storage, sector coupling and the rest of the elements will be added in the otpimization and its impact on the optimal development of the system will be analyzed in a second paper of this research area. Special attention will be put on transmission investments and the influence on the offshore grid topology in these. 

2. System adequacy and balancing costs 

Working on research area 2 will consist of developing the methodology for linking energy system model of the day ahead market to close-to-real-time markets to further investigate on the need for flexibility in the system and the required back up capacity to ensure security of supply and stability of the grid. Balmorel will be used to simulate the Day Ahead market, and it will be linked to close-to-real-time market model to calculate the balancing requirements. Intensive model development is expected in this research area. The first paper of this research area will focus on investigating on the system adequacy of the investment optimization. The current electricity markets will be simulated to analyze the need for additional capacity and to estimate the balancing needs and corresponding costs. The output of this analysis will be looped into the investment optimization to perform the next iteration, until the system that ensures system adequacy and minimizes balancing costs is found. Secondly, possibility of reducing automatic balancing reserve cost and volume will be investigated through different market based reserve solutions in a second paper. Additionally, the impact of international cooperation on the balancing needs will be also analyzed. 

3. Framework conditions

Working on research area 3 will consist of analyzing the status quo of energy market design and regulatory framework to further investigate on the impact of the design of these elements on the optimal development of the energy system. This task will imply in depth surveys at country level with respect to current and planned regulation such us taxes and energy market regulation. Based on microeconomic theory analysis of taxes and regulation will be carried out in order to suggest a regulatory pathway to achieve the optimal market design. This work is meant to be reflected in one paper.

4. Environment 

Working on research area 4 will consist of investigating the impact of the environmental goals to limit climate change in the optimal development of the energy system. This work will require intensive data gathering in terms of CO2 emission allowances. Under this research area, the influence of current framework conditions, international cooperation, and market design in the optimal development of the energy system that fulfills the climate goals will be further investigated and summarized in a journal paper. 

Relevant literature 

1. Karlsson K. et al. (2018) The Role of Population, Affluence, Technological Development and Diet in a Below 2 °C World. In: Giannakidis G., Karlsson K., Labriet M., Gallachóir B. (eds) Limiting Global Warming to Well Below 2 °C: Energy System Modelling and Policy Development. Lecture Notes in Energy, vol 64. Springer, Cham
2. Lund, P., Lindgren, J., Mikkola, J. & Salpakari, J. 2015. Review of energy system flexibility measures to enable high levels of variable renewable energy. Renewable and sustainable energy reviews. 
3. IMPROGRES, »Improvement of the Social Optimal Outcome of Market Integration of DG/RES in European Electricity Markets,« [Online]. Available: http://www.improgres.org/. [Senest hentet eller vist den 05 09 2015]. 
4. Münster, M., Morthorst, P. E., et al, 2012, The role of district heating in the future Danish energy system, Energy, Vol. 48, pp. 47‐55. 
5. Hirth, Lion, 2013. The Market Value of Variable Renewables, Energy Economics 38: 218–236. 
6. NSCOGI, "The North Seas Countries’ Offshore Grid Initiative   Discussion Paper 2: Integrated Offshore Networks and The Electricity Target Model. Deliverable 3 – Final Version. Working Group 2 – Market and Regulatory issues", 2014.
7. T. Trötscher og M. Korpås, »A framework to determine optimal offshore grid structures for wind power integration and power exchange,« Wind Energy, årg. 14, nr. 8, pp. 977‐992, 2011.  
8.European Commission ‐12. DG for Energy, (2011). “Energy Infrastructure Priorities for 2020 and beyond  - A Blueprint for an Integrated European Energy Network,” Available: https://ec.europa.eu/energy /sites/ener/files/documents/2011_energy_infrastructure_en.pdf. 9. J.D. Decker et al., (2011). “Offshore Electricity Grid Infrastructure in Europe”, Available: https://ec.europa.eu/energy/intelligent/projects/ sites/iee‐projects/files/projects/documents/offshoregrid_offshore_electricity_grid_infrastructure_in_europe_en.pdf. NSCOGI, (2012). “Working Group 1 – Grid Configuration”, Available: http://www.benelux.int/files/1414/0923/4478/North_Seas_Grid_Study.pdf
10. I. Konstantelos et al., (2017). “Integrated North Sea grids: The costs, the benefits and their distribution between countries.” Energy Policy, vol 101, pp. 28‐41. 
11. Gea‐Bermúdez J, Pade L.L, Papakonstantinou A. Koivisto, M.J. 2018. North Sea Offshore Grid ‐. Effects of integration towards 2050, EEM18
12. I. Konstantelos, R. Moreno and G. Strbac, (2017). “Coordination and uncertainty in strategic network investment: Case on the North Seas Grid.” Energy Economics, vol. 64, pp. 131‐148.
13. F. Wiese et al., (2018). “Balmorel open source energy system model.” Energy Strategy Reviews, vol 20, pp. 26‐34. 



Juan Gea-Bermudez
PhD student
DTU Management
+45 20 11 73 51