Abstract: Thermoelectric coolers (TECs) are constructed with a solid-state energy-conversion technology that exploits the Peltier effect to convert electrical energy into thermal energy for cooling. This technology is attracting increasing interest due to its advantages, such as the absence of moving parts, the use of non-toxic refrigerants, and robustness. Thermoelectric refrigerators (TERs) are manufactured based on TECs together with control systems to maintain the temperature in the desired range. The presentation initially addresses the basic principles of a TER unit. The TER structure and the key energy indicators, such as cooling capacity, input electrical power, figure of merit, and coefficient of performance to represent the design and performance of the TEC inside the TER, are illustrated. TERs also have the potential to be a valuable tool for managing electricity demand and providing energy services through demand response programs to reduce peak electricity demand and improve grid efficiency. In this respect, this presentation discusses how a TER aggregation can meet the grid operator's requirements for modifying the demand while minimizing the information exchange between the TER aggregator and the individual refrigerators. This approach enables bidirectional flexibility in energy consumption, allowing a collective array of loads to provide essential grid-balancing services.