The increasing presence of distributed energy resources, information and intelligence in the electricity infrastructure increases the possibilities for larger economic efficiency of power systems. This work shows the possible cost advantages of applying a model predictive control (MPC) strategy to residential energy systems. MPC can take future information on energy demand and prices into account and might lead to lower energy costs for end consumers. The main objective in this paper is to illustrate the potential for operational cost savings when adopting MPC in the local control of residential energy systems, thereby mainly focusing on micro combined heat and power systems (micro-CHP). We conclude that the pricing regime of household energy has a large influence on potential cost savings.