Sascha Thorsten Schröder

Market impact of an offshore grid — A case study

The combination of offshore wind generation with international transmission cables is a highly discussed topic in Europe, especially for the North Sea and the Baltic Sea. The offshore wind park location Kriegers Flak in the Baltic Sea could combine offshore wind generation in the Swedish, German and Danish zones, and several design options with regard to cabling are under discussion. Choosing a certain option has a strong impact on congestion rents between power markets as well as on the income of the offshore wind park operators. This paper includes the planned Kriegers Flak offshore node in the WILMAR model, which is an optimization model reflecting the European power markets. That way, the impact of different suggested topologies on the day-ahead power markets in the different countries can be assessed.

Efficiency of continuous double auctions in the electricity market

Intra-day electricity markets are considered as important mechanisms to reconcile short-term fluctuations of energy production with consumption. This even gains in significance in systems with heavy intermittent production at virtually no variable costs, such as wind energy. In Europe, intra-day markets are often designed as continuous double auctions where bid and ask orders are collected continuously, ranked by price and time of arrival. Although this market type can be considered as delivering more or less efficient results, the trading process itself is time-consuming. This poses the question whether continuous markets yield comparably good results when flexibility of market participants to change their schedules at short notice is costlier than having changed them earlier. We apply an extended zero-intelligent-trader simulation model to assess the impact of costly flexibility on market outcomes. We find that costly flexibility with a correspondig demand for flexibility may negatively affect the efficiency of continuous double auctions. For the energy market, this could imply that the markets ability to exploit flexibility is systematically limited.

A modelling breakthrough for market design analysis to test massive intermittent generation integration in markets results of selected OPTIMATE studies

The OPTIMATE1 platform focuses on electricity system and market designs modelling in order to assess current and innovative designs in Europe. The current paper describes the results of the first validation studies conducted with the tool. These studies deal with day-ahead market rules, load flexibility, cross-border management and intermittent renewable support schemes with a view to better integrating large amounts of renewable energy in Europe. Market and system designs were assessed based on economic efficiency, security of supply2 and environmental impact3 indicators. These results give a promising insight into the tool and its possible future use by transmission system operators, regulators, and other public entities.

Support schemes and market design in international offshore grids

International offshore grids can combine the grid connection of offshore wind parks with the possibility for international power trading in the future. This paper investigates the choice of support scheme and power market design in international offshore grids and derives resulting incentives. For example, day-ahead market design could be chosen such that an offshore wind park is affiliated to a national country or placed in a neutral offshore hub. With regard to balancing, an offshore wind parks access to a specific country may be blocked due to interconnector congestion from power trading. Hence, a countrys offshore wind park included in an international offshore grid faces a different economic situation than one which is only connected to its home country. It is argued that there is a redistributive effect between offshore wind park income, congestion rents of the interconnectors and necessary support. For a stable investment framework in the near future, a tendering/feed-in tariff may be the best choice. It avoids exposing wind farms to balancing with multiple countries. In the long run, also other support scheme options may be of interest.