Abstract: An integrated system to provide both heat and electric power. The integrated, or cogeneration, system operates with an organic working fluid that circulates in a Rankine-type cycle, where the organic working fluid is superheated by a heat source, expanded through an involute spiral wrap (scroll) expander such that the organic working fluid remains superheated through the expander, cooled in a condenser, and pressurized by a pump. Heat exchange loops within the system define hot water production capability for use in space heating and domestic hot water, while the generator is coupled to the scroll expander to generate electricity.