Analysis of a hybrid (topping/bottoming) ORC based CHP configuration integrating a new evaporator design concept for residential applications

•Design principles of an evaporator for a residential scale ORC based CHP system.•Residential ORC based CHP request direct vaporization to retrofit combi-boilers.•Integration of a post-heater and ORC-evaporator creating a hybrid CHP scheme.•CHP thermal energy is produced stepwise in a hybrid (topping/bottoming) scheme.•Primary energy savings and net power output are increased in hybrid configuration.