The invention is directed to an energy efficient thermoelectric heat pump assembly. The thermoelectric heat pump assembly preferably includes two to nine thermoelectric unit layers capable of active use of the Peltier effect; and at least one capacitance spacer block suitable for storing heat and providing a delayed thermal reaction time of the assembly. The capacitance spacer block is thermally connected between the thermoelectric unit layers. The present invention further relates to a thermoelectric transport and storage devices for transporting or storing temperature sensitive goods, for example, vaccines, chemicals, biologicals, and other temperature sensitive goods. Preferably the transport or storage devices are configured and provide on-board energy storage for sustaining, for multiple days, at a constant-temperature, with an acceptable temperature variation band.