Overcoming the challenges of variable renewable energy - on mitigating risks, enhancing value, and providing flexibility

The inherent characteristics of renewable energy resources, in particular their variability and uncertainty, pose challenges to system operators, energy suppliers and power plant operators. Bringing together three essays, this dissertation sheds light on how operators of individual renewable power plants can make use of innovative technologies such as Power-to-Gas (PtG) technology, electric energy storage, and sector coupling in order to address these challenges. Essay 1 investigates how operators of wind farms can deploy electric energy storage to mitigate risks that arise from an uncertain renewable production. The results indicate that electric energy storage is in the long run an economically viable instrument for mitigating short-term market risks. Essay 2 addresses the decreasing market value of intermittent renewable generation by analyzing the suitability of PtG technology to increase the value of wind and photovoltaic production. I show that PtG can be instrumentalized to increase the value of onshore wind and photovoltaic generation - in the long run as well as in the short run. Essay 3 examines whether operators of deep geothermal power plants can efficiently provide flexibility to an energy system through flexible co-generation of heat and power. I conclude that it is a viable strategy for operators to flexibly co-generate heat and power, yet one with limited impact on the overall profitability of the plant. Overall, this dissertation contributes to a better understanding of the role that electric energy storage, PtG technology, and sector coupling can play in supporting the integration of variable renewable energy. Operators of renewable power plants may make use of the results presented here to develop business models that tackle the challenges of variable renewable energy.