This paper aims to empirically investigate consumers’ preference structures and their willingness to pay for key features of future residential electric power services that they have not experienced in the regulated market. Using a choice experiment based on conjoint survey and applying a mixed logit model, we quantitatively estimate individual utility functions for certain important attributes such as type of service-providing company, installation of smart meter devices, introduction of E-prosumer groups, relaxation of progressive electricity billing system, and share of renewable energy in the generation mix. The analysis reveals that households prefer installation of smart meter devices and introduction of E-prosumer groups, and are willing to pay 10,044 KRW/year (USD 8.97/year) and 5,222 KRW/year (USD 4.66/year), respectively, for these services. However, households dislike the participation of privately-owned companies under the competitive market structure, owing to the possibility of a rise in the electricity price.