Optimal level of supply security in the power sector with growing shares of fluctuating renewable energy

摘要

In modern societies, energy supply security is an essential factor for economic growth. However, the provision ofsupply security is also associated with cost. In a welfare maximizing society, the optimal level of supply security isgiven if the marginal cost is equal to the marginal benefit. We first evaluate the level of supply security using aprobabilistic approach for a year taking conventional as well as unconventional generation technologies intoaccount. Using these insights as well as recent estimates on the value of lost load, we deduce and discuss the welfareoptimal level of supply security.MethodsWe develop probabilistic models to assess the level of supply security for1. the availability of individual conventional generators using a recursive convolution and2. the feed-ins of a given population for renewable power plants using a sliding window technique.Both probabilistic models are then combined into a single probabilistic model using a Monte Carlo simulation.Using the model’s results as well as as the newest estimates for the so-called value of lost load, we deduce theoptimal level of supply security.ResultsAs a result of the model, we receive a characteristic curve for the secured available generation capacity independence of the chosen level for supply security for each hour of the year.As a result of the model, we obtain the contribution to secured supply for the different technologies includingfluctuating renewable power generation. In the case of Germany, our results indicate that wind power onylycontributes to the peak load with approximately seven percent of its installed generation capacity.Furthermore, using recent estimates for the so-called value of lost load, we estimate the optimal tolerable loss ofload duration. In the case of Germany, this equals about half an hour within a year.ConclusionsThe results of the model allow an orientation for a welfare optimal level of supply security. Such estimations areparticularly helpful when discussing secured supply in times of increasing shares of renewable power generationand policy mechanisms to ensure security of supply.