The invention relates to a system (2) for generating non-propulsive energy in an aircraft, including: an auxiliary power unit (20) including a gas turbine (21) and a fuel cell (22); a pathway (23) for the intake of outside air into the aircraft; an exhaust pipe (24) of the gas turbine, the system being characterized in that the air intake pathway (23) includes a pipe (230) for cooling the fuel pipe, in that the pipe is in fluid communication with the exhaust pipe (24) of the gas turbine such that the ejection of the gas from the gas turbine into the exhaust pipe causes a suction of the air outside the aircraft into the cooling pipe (230) by Venturi effect. The invention also relates to a method for generating non-propulsive energy.