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.
1 Generally, this costs about $300 to $700 for gas and $700 to $1,800 for oil. 2  Removal of the old unit can range from $300 to $1,500 or more. 3  Boilers rated at 95 percent efficiency or higher are eligible for a $150 federal tax credit through Energy Star. Generally, this costs about $300 to $700 for gas and $700 to $1,800 for oil. 2  Removal of the old unit can range from $300 to $1,500 or more. 3  Boilers rated at 95 percent efficiency or higher are eligible for a $150 federal tax credit through Energy Star.