Pellet stove inserts burns pellets at a constant rate using an electric motor & a screw to feed pellets into the burn chamber. When the power fails the stove stops working.
The Gravity Feed Pellet Fireplace Insert has no feed motor. Instead gravity feeds pellets at a constant rate. During a power outage the pellets continue feeding by gravity. Heat is dissipated into the room by passive convection, and radiation. The technology can be retrofitted to a wood burning fireplace insert as shown in the photos.