Methods and systems for utilizing waste heat for a hybrid vehicle

A method for operating an engine, comprising:

• operating an engine;
• transferring engine exhaust gas heat energy from the engine to a thermal energy storage device via an engine exhaust gas heat exchanger;
• and
• transferring heat energy from the thermal energy storage device to a passenger cabin heater core while the engine has stopped rotating.

A method for operating an engine, comprising:

• operating an engine;
• storing energy in exhaust gases from the engine to a phase change material;
• and
• releasing energy stored in the phase change material to an engine coolant heat exchanger, the engine coolant heat exchanger in fluidic communication with the engine and a passenger cabin heater core.