Friedrich Kunz

Improving Congestion Management - How to Facilitate the Integration of Renewable Generation in Germany

In this paper we analyze the German congestion management regime and assess future congestion management costs given a higher share of intermittent renewable generation. In this context, cost-based re-dispatching of power plants and technical flexibility through topology optimization are considered as market-based and technical congestion management methods. To replicate the current market regime in Germany a two-step procedure is chosen consisting of a transactional spot market model and a congestion management model. The results show that currently congestion can mainly be managed by optimizing the network topology. However, congestion management costs tend to increase significantly in future years even if proposed network extensions are taken into account due to higher wind generation and proposed power plant investments, both located mainly in northern Germany. The phase-out of German nuclear power plants additionally impacts congestion management costs. We conclude that there is a need for improving the current congestion management regime.

Development Scenarios for the North and Baltic Sea Grid: A Welfare Economic Analysis

The North and Baltic Sea Grid is one of the largest pan-European infrastructure projects raising high hopes regarding the potential of harnessing large amounts of renewable electricity, but also concerns about the implementation in largely nationally dominated regulatory regimes. The paper develops three idealtype development scenarios and quantifies the technical-economic effects: i) the Status quo in which engagement in the North and Baltic Sea is largely nationally driven; ii) a Trade scenario dominated by bilateral contracts and point-to-point connections; and iii) a Meshed scenario of fully interconnected cables both in the North Sea and the Baltic Sea, a truly pan-European infrastructure. We find that in terms of overall welfare, the meshed solution is superior; however, from a distributional perspective there are losers of such a scheme, e.g. the incumbent electricity generators in France, Germany, and Poland, and the consumers in low-price countries, e.g. Norway and Sweden. Merchant transmission financing, based on congestion rents only, does not seem to be a sustainable option to provide sufficient network capacities, and much of the investment will have to be regulated to come about. We also find strong interdependencies between offshore grid expansion and the subsequent onshore network.

Security of Supply and Electricity Network Flows after a Phase-Out of Germany’s Nuclear Plants: Any Trouble Ahead?

This paper, which examines the impacts of phasing out nuclear power in Germany, is the first to include an analysis of energy supply security and critical line flows in both the German and Central European electricity networks. The technical-economic model of the European electricity market, ELMOD, is used to simulate alternative power plant dispatch, imports, exports, and network use for a representative winter day. The results suggest that the shutdown of Germany’s nuclear plants will result in higher net imports, especially from the Netherlands, Austria, and Poland, and that electricity generation from fossil fuels will increase slightly in Germany and in Central Europe. We find that no additional imports will come from nuclear plants since they are already fully utilized in the merit order, and that electricity prices will rise on average by a few Euros per MWh. We conclude that closing the seven nuclear power plants within the government’s moratorium will cause no significant supply security issues or network constraints and an eventual full phase-out seem to be possible due to the completion of several new conventional power plants now under construction. Finally, we suggest that a nuclear phase-out in Germany within the next 3-7 years will not undermine security of supply and network stability in Germany and Central Europe.

A Coordinated Strategic Reserve to Safeguard the European Energy Transition

In Germany and beyond, various capacity mechanisms are currently being discussed with a view to improving the security of electricity supply. One of these mechanisms is a strategic reserve that retains generation capacity for use in times of critical supply shortage. We argue that strategic reserves have specific advantages compared to other capacity mechanisms in the context of the European energy transition. To date, however, the debate on capacity mechanisms has largely been restricted to national contexts. Against this background, we discuss the feasibility and potential benefits of coordinated cross-border strategic reserves to safeguard electricity supply and aid the energy transition in Germany and neighboring countries at large. Setting aside strategic reserve capacity which is deployed only in the event of extreme supply shortages could improve the security of electricity supply without distorting the EU’s internal electricity market. In addition, overall costs may decrease when reserve procurement and activation are coordinated among countries, particularly if combined with flow-based market coupling.

Start Me Up Modeling of Power Plant Start-Up Conditions and Their Impact on Prices

In this paper we compare different approaches to account for start-up costs when modeling electricity markets. We restrict the model formulation to either linear or mixed integer problems in order to guarantee a robust solution. The results indicate that the choice of the model has a significant impact on the resulting market prices and company profit. The models either calculate higher peak prices or prices below marginal costs in off-peak periods but not both. Furthermore, the models perform differently when we apply a large sample, the number of equations having an important impact. We conclude that different model formulations respond particularly to specific modeling questions.

Integrating Intermittent Renewable Wind Generation - Insights from the Stochastic Electricity Market Model (stELMOD)

In northern Europe wind energy became a dominating renewable energy source due to natural conditions and national support schemes. However, the uncertainty about wind generation affects existing network infrastructure and power production planning of generators and cannot not be fully diminished by wind forecasts. In this paper we develop a stochastic electricity market model to address the impact of uncertain wind generation on electricity markets and commitment decisions of generators. Stochastic programming techniques are used to incorporate uncertain wind generation. The technical characteristics of transporting electrical energy as well as power plants are explicitly taken into account. The consecutive clearing of the electricity markets is incorporated by a rolling planning procedure. The model is applied to the German electricity system covering an exemplary week. Three different cases of considering uncertain wind generation are analyzed. The results indicate that while the bidding behavior in the dayahead market is quite similar the approaches show notable differences in the behavior on the intraday market.

A Welfare Analysis of the Electricity Transmission Regulatory Regime in Germany

We analyze the current regulatory regime for electricity transmission in Germany, which combines network planning with both cost-plus and revenue-cap regulations. After reviewing international experiences on transmission investment, we first make a qualitative assessment of the overall German regime. The German TSOs have in general incentives to overinvest and inefficiently inflate costs. We further develop two models to analyze the transmission planning process. In the first model there is no trade-off between transmission expansion and generation dispatch. This is a modeling set-up similar to the one actually used in the German transmission planning (Netzentwicklungsplan). A second model alternatively allows for such a trade-off, and thus represents an optimal way of transmission network planning. Simulations with the two models are carried out and compared so as to illustrate the amount of excessive transmission capacity investment and welfare losses associated with the current regime.

Applying experiments to auctions in electricity markets

We analyze the bidding behavior in a single sided uniform auction and in a pay-as-bid auction using an experimental approach. This study focuses on the impact of the risk attitude of participating subjects. The experiments are conducted under a stable demand environment and with homogeneous groups consisting each of five participants either with a complete risk seeking or a complete risk averse attitude. The results show that a uniform auction is significantly affected by risk attitude of the participants. Standard deviation of efficiency and prices are higher when playing with risk averse participants. Compared to other existing literature on experimental economics, our results differ substantially and show that risk attitude of participants is a factor that needs to be taken into account especially when conducting experiments with small groups.

Coordinating Cross-Country Congestion Management

We employ a detailed two-stage model to simulate the operation of the Central Eastern European electricity market and network. Implementing different cases of coordination in congestion management between national transmission system operators, numerical results show the beneficial impact of closer cooperation. Specific steps comprise the sharing of network and dispatch information, cross-border counter-trading, and multilateral redispatch in a flow-based congestion management framework. Efficiency gains are accompanied by distributional effects. Closer economic cooperation becomes especially relevant against the background of changing spatial generation patterns, deeper international integration ofnational systems, and spillovers of national developments to adjacent systems.

The Impact of Participant’s Risk Attitude on Auctions Results: An Experimental Approach to Electricity Markets

We analyze the impact of the risk attitude of participating subjects in both single-sided uniform and pay-as-bid auctions using an experimental approach. The experiments are conducted in a stable demand environment with homogeneous groups, each consisting of five participants that exhibit either complete risk seeking or complete risk aversion. The results show that risk attitudes significantly affect the outcome of uniform auctions. We also note that our results differ substantially from other literature on experimental economics. We conclude that it is important to consider participants’ risk attitudes especially when conducting experiments with small groups.