In Japan about 16 million units of distribution transformers are in service. These transformers are expending a huge amount of energy in the form of no load loss and load loss. Among these losses, no load loss is major. No load loss can be saved dramatically by changing these transformers to amorphous transformers (i.e., amorphous metal-based transformers). This paper estimates the scope of the possible energy saving and reduction of CO2 emissions by the adoption of amorphous transformers in Japan and in China.