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.
These systems have a conversion efficiency of 15 to 35 percent depending on system size and operating parameters. A steam CHP system can reach system efficiency of up to 85 percent. Installed costs range from $1,700 to $3,500 per kW and typ-ically produce energy at a cost of $0.06 to $0.20 per kWh.