In this work, the focus is placed on the proof of concept of a novel control scheme for demand response. The control architecture considers a uniform representation of non-homogeneous distributed energy resources and allows the participation of virtually all system users in electricity markets. The proposed scheme captures the operational planning, the real-time operations, the verification of the energy and service provision, and the financial settlement. The research involves the experimental verification of the proposed control and communication architecture between the aggregator and a system user in a laboratory environment. Emphasis is given on the real-time operations, whereas the case study is about the domestic freezer appliance. The convergence of the demand response system under load frequency control is investigated through simulation studies and the time response is compared to that of conventional balance suppliers in The Netherlands.