Deutsche Version  ACT
Overarching Themes
BMWi
Integrated electricity market model 6.7.2016

Researchers of the Institute of Energy Economics at the University of Cologne investigate interdependencies between different storage technologies and conventional power plants.
© EWI

Analysing energy storage in the electricity system

Scientists develoedp an integrated electricity market model. They

analysed the optimal combination of storage, networks and electricity in

the European electricity system looks like. The model identifies a

current system that enables efficient interaction of all components

mentioned at minimal cost.

Project status Project completed
Project duration August 2013 until December 2015

Greenhouse gas emission reduction, energy efficiency and development of renewable energy sources (RES) are among the key objectives, in addition to safe and economical energy supply, of European and German energy and climate policy.  In particular, the increase in the share of renewables in electricity generation is politically enforced. This directly influence the development ot the  generation mix: Due to the fluctuating feed-in from renewable energy sources, there is an increasing need for flexibility in the current system. In this respect, flexibel technolgies, especially those which are able to offset the intermittent supply of renewable energy and contribute to the stability of the electricity system, become increasingly important.  Storage could provide a significant contribution due to its technical characteristics, however the role of storage in current systems has yet to be sufficiently researched.

In order to economically assess the future importance and role of energy storage in the European power supply, a comparative cost analysis is performed. A special focus is given to the interdependencies and competitive relationships between different storage technologies and conventional power plants, which are evaluated based on their technological and economical interation with the transmission networks. The economic evaluation of storage is very complex due to the special properties of storage systems. 

The various parts of the project should advance the most current research as well as promote an understanding of the total energy system. The focus is on the role of current and future storage technolgies, as well as their function and significance in interacting with other parts of the power system (e.g., convetional power plants, renewable energy and transmission networks). This integrated approach distinguishes this project from other previous research with focused research questions.

The findings and developed methodology are combined into an integrated electricity market model. In addition, it is analysed how the optimal combination of storage, networks and production in the European electricity system can look like. This allows an efficient power system to be determined.

Sub-projects

Sub-project 1
Consideration of uncertainty for the modelling approach of electricity markets: This sub-project’s target is to deepen the understanding of uncertainty in electricity markets. Due to the fast capacity extension of volatile renewable production such as wind and solar energy, the importance of forecast uncertainties increases. This can have a significant impact to electricity markets. The investigations focus on the impact of trading under uncertainty in the short-term electricity markets (day-ahead and intraday).

Sub-project 2
Investment Behavior in the Electricty System: The target of this sub-project is the analysis of the bidding behavior of  electricity producers and storage operators in the day-ahead market and the balancing power market under different market structures or information asymmetries. A detailed understanding of these markets and the profit maximizing behavior of the participants is a basic prerequisite for the understanding of investment behavior in additional storage technologies. Focus of the investigation is a different information provision to the participants in uniform pricing (UP) or discriminatory pricing (DP) auctions. These are the most commonly used auction designs for day-ahead and balancing power markets. The derived results were assessed based on economic criteria such as welfare, prices, and sold production in the markets.

Sub-project 3
The Role of Storage in the Transmission Network: Target of this sub-project is to analyze the interdependent grid and production capacity extension. Focus of the investigation is the optimization of the allocation and utilization of production, grid and storage capacities in a cost optimal manner. The derived results were assessed based on technical, economic and ecological (CO2) criteria.
 
Sub-project 4
Integrational part: Target of this sub-project is the integration of the previous three sub-projects in an overall analysis. This approach enables to investigate the optimal interaction of storages, grid and production in a European connected system. The focus of the analysis is on the storage capacities under an integration of volatile renewable energies and the corresponding optimal grid infrastructure. The connection of the derived results in the former sub-projects allow further insights. Interdependencies as well as new challenges of an integrated analysis will be identified. This contributes to the overall project target and generates an additional value compared to a separated, sub-project-wise analysis.

Publications and Conference participations

In accordance to this research project, new and deepened insights were generated and resulted in research paper and were presented on scientific conferences. The project resulted in four publications:

Additionally, the research results were presented at high-quality conferences in energy economics:

  • EASAC Electricity Storage Study – 2nd project Meeting, Juni 2015, Cologne: Congestion management in power systems – Long term modeling framework and large scale application. Joachim Bertsch, Simeon Hagspiel, Lisa Just.
  • 2. Wissenschaftsdialog der Bundesnetzagentur, September 2014, Bonn: Coordination between electricity generation and transmission – modeling framework and large scale application. Joachim Bertsch, Simeon Hagspiel, Lisa Just.
  • 14th IAEE European Conference, Rom, October 2014: The Up- and Downside of Hiding Information - Zonal vs Nodal Pricing in Electricity. Joachim Bertsch.
  • 14th IAEE European conference 2014, Rom: Coordination between electricity generation and transmission – modeling framework and large scale application. Joachim Bertsch, Simeon Hagspiel, Lisa Just.
  • IAEE / YEEES European PhD-students Day 2014, Rom: Coordination between electricity generation and transmission – modeling framework and large scale application. Joachim Bertsch, Simeon Hagspiel, Lisa Just.
  • 39th IAEE International conference 2016, Bergen: How to Sell Renewable Electricity - Interactions of the Intraday and Day-Ahead Market Under Uncertainty. Andreas Knaut, Frank Obermüller. Winner of the IAEE Best Student Paper Award.