In the scenario with an 80% renewable share, electricity prices are considerably lower compared to the other scenarios and the number of hours with electricity prices equal to or below zero rises to an astonishing 2 850 hours. A reduced occurrence of electricity prices higher than variable costs in combination with reduced utilisation hours means lower infra-marginal rents for recovering capital costs. Consequently, it is highly questionable whether conventional power plants can be profitably operated with high shares of renewables in energy-only markets with price formation being based on marginal costs.