The cost of hydrogen depends on whether it is produced from natural gas, wind, nuclear, or solar power. It may also rely on other factors such as if it is made at the fueling station or the off-site when produced from natural gas. Usually, the price of producing hydrogen is calculated based on its efficiency over gasoline. Since it is regarded to be at least 5 times more efficient, its cost is also worked out on a similar ratio. The average cost of hydrogen (from natural gas) is $4 to $5 per kilogram, whereas it is $8 to $10 in the case of wind and nuclear and $10 to $12 for solar.