save on something        
phrasal verb with save verb uk/seɪv/ us/seɪv/
 节省,节约
to avoid using something so that you do not have to pay for it
  It was a warm winter, so we saved on electricity. 那是一个暖冬,因此我们省了不少电。 
 
英汉双解词典收录81607条英汉双解翻译词条,基本涵盖了全部常用单词的读音、翻译及用法,是英语学习的有利工具。