  The grid integration of intermittent Renewable Energy Sources (RES) causes
costs for grid operators due to forecast uncertainty and the resulting
production schedule mismatches. These so-called profile service costs are
marginal cost components and can be understood as an insurance fee against RES
production schedule uncertainty that the system operator incurs due to the
obligation to always provide sufficient control reserve capacity for power
imbalance mitigation. This paper studies the situation for the German power
system and the existing German RES support schemes. The profile service costs
incurred by German Transmission System Operators (TSOs) are quantified and
means for cost reduction are discussed. In general, profile service costs are
dependent on the RES prediction error and the specific workings of the power
markets via which the prediction error is balanced. This paper shows both how
the prediction error can be reduced in daily operation as well as how profile
service costs can be reduced via optimization against power markets and/or
active curtailment of RES generation.
