One exception to note: If the food's sitting in an environment where the temperature is over 90Â°F, the USDA says the food should only be left out for one hour, so keep an eye on the clock if you're serving food on a hot day!
Estimated cost of hydrogen per kilogram in a variety of scenarios. With all of this in mind, here are the cost estimates per kilogram (which each include $1.25 for taxes): Hydrogen from natural gas (produced via steam reforming at fueling station). $4 â $5 per kilogram of hydrogen.
However, if used as a fuel, that gallon of LH has one fourth the energy of a gallon of gasoline. The ultimate cost would then be $6.00 per gallon. And some other points to consider. $5.50 per kg is the cost if hydrogen is made from natural gas. If made from electricity, it jumps to about $7.50 per kg. Almost no supplier makes hydrogen from electricity. The price of natural gas also goes up with the price of oil and gasoline.