Experiments on waste heat thermoelectric generator for power transformer and its field application

Abstract Huge waste heat is dissipating from massive power transformers, and recovering such waste heat for power generation and heating purpose attracts attentions of power sectors and scientists. This study demonstrates the possibility of cogeneration of electric power and domestic hot water on the basis of thermoelectric technology. A thermoelectric generator (TEG) unit with 48 TE modules (TEMs) is designed and tested. Experiments showed that an electric power of 13.2 W is generated by the abovementioned TEG unit when the hot-/cold-liquid temperatures are 348.3.0 K and 297.4 K, respectively. Two waste heat TEGs with 80 units, incorporated with a total number of 3840 TEMs, is designed for a 50,000 kVA power transformer in Huzhou city (Zhejiang, China). Field tests indicate that over 800 W of electric power and 200 kW of hot water are cogenerated. The annual energy saving rate is over 173 tce based on the energy reference coefficients of 0.305 kgce/kWh for electricity and 0.0341 kgce/MJ for heating power, respectively. The abovementioned energy saving rate corresponds to a payback period less than 2 years.