In accordance with exemplary embodiments, the present invention provides a transient power source that includes a flywheel that stores kinetic energy. In the event of a loss of main or operating power, the kinetic energy stored in the flywheel is converted into electrical energy. As one example, the rotation of the flywheel drives a generator that converts this mechanical (i.e., kinetic energy) into electrical energy. Additionally, the exemplary flywheel, as one embodiment, generates a cooling airflow for various components of the electrical machine. Thus, the rotation of the flywheel not only generates power, but also cools the various components of the transient power source as well.