Join the Thunderclap for 2016’s National Hydrogen and Fuel Cell Day now! Thunderclap is a tool that lets a message be heard when you and your colleagues/friends say it together. Think of it as an “online flash mob.” Join a Thunderclap, and you and others will share the same message at the same time, spreading an idea through Facebook, Twitter, and Tumblr that cannot be ignored. National Hydrogen and Fuel Cell Day was created to help raise awareness of a clean energy technology that is here now. October 8th (10.08) was chosen in reference to the atomic weight of hydrogen (1.008)