In your opinion which is the most important development in the use of energy? The use in mobile phone chargers in

Question: In your opinion which is the most important development in the use of energy? The use in mobile phone chargers in batteries or in something else completely?
- Keywords:
  batteries,
  development,
  phone
Asked by on 15 Jan 2017. This question was also asked by .
- Meggi answered on 15 Jan 2017:
  
  If looking back, I think some of the most important developments were the air conditioner and the refrigerator. Just think about all the countries which face 30 degree every day…

Question: In your opinion which is the most important development in the use of energy? The use in mobile phone chargers in batteries or in something else completely?