Fundamental unit commitment approaches are of central importance in
energy system modeling for the generation of detailed power plant
schedules. However, existing approaches, which reduce complexity in a
multi-stage process, often fail to generate realistic electricity
prices. A new type of single-stage approach considers market-coupling
implicitly so that, in addition to detailed power plant schedules,
electricity prices reflecting real prices very well can be generated. In
this paper, we show in a back-test for 2014 that an endogenously modeled
market-coupling is the driving factor for the quality of resulting
electricity prices. Conversely, it can be concluded that conventional
multi-stage approaches show a significant distortion of modeled
electricity prices due to missing price signals from neighboring market
zones. Against the background of expanding trading capacities between
market zones within the European power system, this issue becomes
increasingly relevant when fundamentally modeling energy prices.