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.
Hydrogen gas is sold by the kilogram instead of the gallon and at the station we used to fill the Mirai in La Canada, Calif., it was $16.63 per kilogram. The Mirai was three-quarters empty at that point and the tanks hold around 5 kilograms of hydrogen, so it took 3.81 kilograms to fill back it up at a cost of $63.51. The trip meter read 195.3 miles at that point. That put the cost per mile at around $0.33.