A ram air turbine (RAT) system is provided. The RAT system includes a main generator, a RAT power generation unit, first circuitry, a storage device and second circuitry. The main generator and the RAT power generation unit are connectable to an aircraft bus by the first circuitry. The first circuitry includes a first switch which is controllable such that power is selectively provided to the aircraft bus from one of the main generator and the RAT power generation unit. The storage device is connectable to the aircraft bus by the second circuitry. The second circuitry includes a second switch which is controllable such that power is selectively provided to the aircraft bus from the storage device.