In the US, abouthalf of all homesuse natural gas for space and water heating.
So what is hydrogen fuel and what makes it blue?
This involves combining fossil fuels with steam, and heating them to around 800C.
Eventually, you get carbon dioxide (CO2) and hydrogen.
These two gases are then separated.
The hydrogen rainbow
Grey hydrogen is the most common form.
Black hydrogen is produced using bituminous coal a tar-like substance.
But blue hydrogen, its hoped, particularly by theUSandUKgovernments, is different.
Out of the blue
The process of making blue hydrogen also requires a lot of energy.
What is certain is that blue hydrogen may not be as green as it once appeared.
