A Multistage Stochastic Optimization Model for Trading on the German Intraday Power Market

As the German Intraday power market has grown steadily over the last seven years, the academic and commercial interest in mathematical optimization of decision making related to the market has grown. The relevant decisions include both production and trading of 24 hourly delivery products. The trading is organized as a Continuous Auction implemented as a Limit Order Book for each delivery product. The market opens soon after the clearing of the Day-Ahead market and closes just before delivery. As both the delivery products and the trading decisions for a given delivery product happen sequentially, the decision structure has a doubly dynamic trading structure that makes it hard to optimize. Additionally, the liquidity in the market is limited, further complicating the optimization. Due to the high complexity of the problem, existing papers that attempt to optimize decision making related to the Intraday market make several simplifying assumptions. In order to find the best combination of modeling assumptions to make, an extensive literature review is performed, focusing on the modeling assumptions in each paper. It is found that there is disagreement in the contemporary literature about how to best model the problem. In particular, the relevant papers optimize either order placement in the market, or physical power dispatch, and neglect the other type of decision. In this thesis, the Intraday Trading Problem (ITP) is defined to include both the order placement and the production optimization. The ITP is further broken down into three subproblems: the price forecasting problem, the cost estimation problem and the strategy formulation problem. Based on the points of disagreement in the related literature, a set of modeling assumptions is defined, mostly relating to the strategy formulation problem. The goal of the thesis is to explore which of the modeling assumptions that are the most profitable to make, and estimate the impact on the objective function of making a given combination of assumptions. Based on the set of modeling assumptions, a proposed benchmark model and six models inspired by the existing literature are defined. In order to test the model, a detailed analysis of historical EPEX Intraday order book data is performed, and a model of the market is developed. The estimation of all the relevant market parameters is a significant expansion compared to the market analyses performed in the existing literature. Small scenario trees are developed based on the market analysis, and the models are tested on a "forest" of semi-optimized, semi-randomized scenario trees. It is found that the proposed benchmark model outperforms the alternative models with a 4-41% premium on the objective value. Finally, the theoretical reasons for the improved performance is discussed, and three avenues for future research are outlined

Power Price Scenarios - Results from the Reference scenario and the Low Emission scenario

This report is written as a part of HydroCen WP3.1. The aim of the research described in this report is to show and quantify variation in power prices in Northern Europe in 2030. The background for this study is the need for reduction of green-house-gases (GHG) emissions and EUs policy for transforming the energy system and in particular the power system to low carbon systems. The assessment of power prices in Northern Europe in 2030 uses scenario methodology. A Reference scenario and Low emission scenario are defined for 2030. The Reference scenario is based on a renewable target of 27% in 2030 in the energy mix. The Low emission scenario aims to reflect the most recent targets and ambitions for the power sys-tem in Northern Europe in 2030. In this scenario, a larger share of the power production is based on wind and solar resources. The report compose and discusses results from the Reference and Low emission sce-narios with focus on production mix and impact on power prices. The aim is to achieve an improved un-derstanding of price characteristics and the price drivers in 2030. The results show that the price variation increase in the Low emissions scenario as more renewables are added to the system. In Norway the maximum price difference within a 24-hour period, a week and a month approximately doubles in the Low emission scenario compared to the Reference scenario. Further quantitative measures of this increase are shown in the report. Furthermore, it is shown that the short-term price variation is much higher in Germany and Great Britain than in Norway. The income for a hydro-power producer in Southern Norway is shown to hardly increase in the Low emission scenario compared to the Reference scenario as the average power price decrease. However, it is also show that hydropower producers achieve a higher value per unit of energy produced than wind and solar power plants and that the value of flexibility increases in the Low emission scenario compared to the Reference scenario. In the Low emission scenario, there are periods with zero prices in the South of Norway. A main part of the nearly zero prices are observed during the summer but there are also occurrences in the winter. More detailed economic results are given for some hydropower plants, some of which include pumping. The realized value of hydropower plants with pumping might be underestimated.© SINTEF Energy AS 2019. The publication may freely be cited with source acknowledgement

Developing a wind and solar power data model for Europe with high spatial-temporal resolution

This paper describes a wind and solar power production model for Europe based on the numerical weather prediction model COSMO-EU. The COSMO-EU model has hourly time resolution and a spatial resolution of 7 km x 7 km for Europe. The model is validated against power production information from the system operators in Denmark, Germany and Spain. Mean Average Error (MAE) (hourly error averaged for a year) relative to the wind installed capacity is in the range 4.9% -5.9% for wind power production and 2.4%-5.5% for PV (photovoltaic) power production. Root Mean Square Error is in the range 6.2%-7.6% and 4.5%-9.3% for wind and PV power production respectively. The results are compared with similar modelling based on wind and radiation data from the NCEP reanalysis model. This model has six hourly time resolution for wind resources and daily resolution for radiation data. Modelling of wind power production in Denmark, German and Spain has a MAE in the range 5.6%-8.5% and solar PV production 4.9%-6.4% for the NCEP reanalysis model.acceptedVersionThis is the author's version of an article that has been accepted for publication in 2016 51th International Universities Power Engineering Conference (UPEC) in Portugal. The final version of record will be available at IEEExplore.Copyright (c) 2016 IEEE. Personal use is permitted. For any other purposes, permission must be obtained from the IEEE by emailing [email protected]

Norway as a Battery for the Future European Power System – Comparison of Two Different Methodological Approaches

This paper compares the simulation results for two stochastic optimization power market models. EMPS uses aggregation and heuristics to calculate the optimal dispatch. SOVN simulates the operation of the power system in one large linear programming problem taking each single plant and reservoir into consideration. The comparison is for a future system in Europe where wind and solar power production supplies 61% of the annual demand. Three different alternatives for the Norwegian hydropower system is studied: present generation capacity (about 30 GW), increased capacity to about 41 GW and further to about 49 GW. The analyses show that SOVN to a larger degree than EMPS manage to increase production in high price periods and pump in low price periods. This particularly applies to the weeks before the change from the depletion (winter) to the filling (summer) period. This better ability to exploit the flexibility of the hydropower system is due to applying a formal optimization in SOVN compared to advanced heuristics in EMPS. For regions without pumping possibility, there is less difference between the models.acceptedVersionThis is a post-peer-review, pre-copyedit version of an article. The final authenticated version is available online at: https://doi.org/10.1007/978-3-030-03311-8_1

Balancing future variable wind and solar power production in Central West Europe with Norwegian hydropower Energy

Norwegian hydropower has an excellent potential to balance power production in a future Central-West European power system with large shares of variable wind and solar resources. The assessment of the realistic potential for Norwegian hydropower to deliver flexibility is based on two pillars, adequate hydropower modelling and the sufficient geographical area covered in the model. Analyses are done with state-of-the-art models including a detailed description of cascaded water-courses with more than thousand reservoirs. Interoperability between hydropower and renewable energy sources is ensured as the entire European electricity generation from renewables with high geographic and temporal resolution is included in the study. To properly account for the full uncertainty of weather variables, many historic years of climate data are applied. The results show that without more flexibility in generation or demand, power prices become very volatile and show expedient periods with capacity deficit and curtailment of demand. Prices vary significantly both from hour-to-hour and from year-to-year. Increases in flexible hydropower provide large benefits to the system: significantly decreasing peak prices and reducing the involuntary shedding of demand. As short-term effects become increasingly important due to large-scale integration of renewable energy sources the correct modelling of flexible hydropower is highly important.acceptedVersion© 2018. This is the authors’ accepted and refereed manuscript to the article. Locked until 21.11.2020 due to copyright restrictions. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0

Contestation, contingency, and justice in the Nordic low-carbon energy transition

The five Nordic countries have aggressive climate and energy policies in place and have already emerged to be leaders in renewable energy and energy efficiency. Denmark is renowned for its pioneering use of wind energy, Finland and Sweden bioenergy, Norway hydroelectricity and Iceland geothermal energy. All countries aim to be virtually “fossil free” by 2050. This study explores the Nordic energy transition through the lens of three interconnected research questions: How are they doing it? What challenges exist? And what broader lessons result for energy policy? The study firstly investigates the pathways necessary for these five countries to achieve their low-carbon goals. It argues that a concerted effort must be made to (1) promote decentralized and renewable forms of electricity supply; (2) shift to more sustainable forms of transport; (3) further improve the energy efficiency of residential and commercial buildings; and (4) adopt carbon capture and storage technologies for industry. However, the section that follows emphasizes some of the empirical barriers the Nordic transition must confront, namely political contestation, technological contingency, and social justice and recognition concerns. The study concludes with implications for what such historical progress, and future transition pathways, mean for both energy researchers and energy planners

Thoracic Radiotherapy in Limited-Stage SCLC—a Population-Based Study of Patterns of Care in Norway From 2000 Until 2018

Introduction Twice-daily (BID) thoracic radiotherapy (TRT) of 45 Gy per 30 fractions is recommended for limited-stage (LS) SCLC, but most patients are treated with once-daily (OD) schedules owing to toxicity concerns and logistic challenges. An alternative is hypofractionated OD TRT of 40 to 42 Gy per 15 fractions. A randomized trial by our group indicated that TRT of 45 Gy per 30 fractions is more effective than TRT of 42 Gy per 15 fractions, and because it was not more toxic, 45 BID replaced 42 OD as the recommended schedule in Norway. The aims of this study were to evaluate to what extent BID TRT has been implemented in Norway and whether this practice change has led to improved survival. Methods Data on all patients diagnosed with LS SCLC from 2000 until 2018 were collected from the Cancer Registry of Norway, containing nearly complete data on cancer diagnosis, radiotherapy, and survival. Results A total of 2222 patients were identified; median age was 69 years, 51.8% were women, and 87.1% had stage II to III disease. Overall, 64.6% received TRT. The use of BID TRT increased from 1.8% (2000–2004) to 83.2% (2015–2018). Median overall survival among patients receiving curative TRT improved significantly during the study period (2000–2004: 17.9 mo, 2015–2018: 25.0 mo, p = 0.0023), and patients receiving 45 BID had significantly longer median overall survival than patients receiving 42 OD (BID: 26.2 mo, OD: 19.6 mo, p = 0.0015). Conclusions BID TRT has replaced hypofractionated OD TRT as the standard treatment of LS SCLC in Norway which has led to a significant (p = 0.0023) and clinically relevant survival improvement. Previous article in issuepublishedVersio