The demand for energy has increased at a steep rate over the past two decades, but the amount of energy available is at a standstill. Furthermore, there are very few successful techniques for the efficient use of energy and its conservation. This chapter proposes the design and analysis of a waste heat recovery system for an air conditioner. Because of their low-grade output, waste heat from air conditioners is overlooked as a source of heat for electricity generation. Thermoelectric generator (TEG) modules coupled in a series−parallel configuration were used to convert the waste heat from an AC condenser’s outlet into its equivalent electrical energy. The heat, which would otherwise be radiated, is captured and concentrated using an aluminum sheet duct. This arrangement increased the outlet temperature by 28%. Using an ice pack instead of plain water on the cold side of the TEG modules resulted in an 80% increase in output voltage. Temperature, voltage, and current data were sensed and measured under differing circumstances in real time with the help of three sensors: DS18B20 (temperature), a voltage sensor, and ACS712 (current). An ARDUINO UNO processor is used to record all the data on a computer using an interface software-based algorithm for further analysis. After evaluating the performance of all series−parallel TEG module combinations, a four-series−four-parallel TEG combination (4S4P) is chosen to be used. In order to run a 5 V LED load, a power electronic converter in the form of a boost converter is interfaced to enhance the voltage level.