Operating reserve demand curves (ORDCs) have become part of the electricity market design in several power systems. They improve the security of supply through enhanced peak prices that occur already when the system is running low on operating reserves, before an actual shortfall occurs. Previous research, however, suggests that the ORDC's impact on resource adequacy would be thwarted by the merit order effect.Hence, we propose a methodology to model the investment in markets with ORDC, which specifically captures the interaction with renewable deployment.