A control unit (5) for controlling each device which constitutes a electric
power generator set (1) is provided with an operation-and-display device
(28) so constituted as to calculate each electric power value data and each
electric energy data on external electric power, generated electric power, and
load electric power on the basis of sensed data on each value of external electric
power and generated electric power transmitted from inverters (6a,
6b) and as to store these calculated data and the sensed data, and connected
to the electric power generator set (1) by wires or radio. A cogeneration
system comprising the electric power generator set (1) is so constituted
that data on the electric power generation current value of the external electric
power source and the electric power generator set (1) and data on water-heat
energy are sensed and transmitted to the control system (2), and that the
control system calculates data on an external electric energy, a generated electric
energy, a load electric energy, a water-heat energy recovery quantity, and an energy
efficiency to display the calculated data on the operation-and-display device (28).
