Firstly, the bingo style cards that you speak of are actually less secure than even passwords, as they operate within a much smaller set of finite values. Not to mention that a simple phishing attack would reveal the entire card for future use by any fraudster.

Secondly, newer, greener technologies such as OTP’s generated by software applications on mobile phones and invisible user authentication based on things like device profiling, geo-location, authentication velocity etc. are becoming more popular.

I do agree that greener alternatives need to be considered however I do not believe that bingo cards are the answer.