Hawaii Natural Energy Institute, January 2007
Consider the following riddle:
I am renewable;
I am a chemical element;
as a fuel I am often less expensive ($/GJ) than natural gas;
my energy density (GJ/m3) can exceed that of ethanol or LPG;
and my combustion does not add to the CO2 in the atmosphere;
I am easily stored and safe to transport;
I clean the water you drink and the air you breathe;
Plants grow best in soils that are enriched with me;
I am a key ingredient in the production of semiconductors;
When eaten I settle an upset stomach and clean the intestines; and
No one is afraid of me!
What am I?