A hybrid heat engine system includes a valve configured to provide first fluid from a heat source. The hybrid heat engine system further includes one or more first pipes fluidly coupled between the valve and a turbine. The one or more first pipes house a second fluid. The hybrid heat engine system further includes a chamber disposed between the valve and the one or more first pipes. The hybrid heat engine system further includes a piston disposed in the chamber between the first fluid and the second fluid. At least a portion of the second fluid is to be pushed through the turbine to generate energy responsive to actuation of the valve.