Whether it’s green, blue, or turquoise hydrogen, S&P Global says that the simultaneous development of various hydrogen production methods will be building blocks necessary for scaling up the clean hydrogen economy.

The research group reported that stakeholders across the US hydrogen economy in a Centre for Strategic and International Studies panel discussion flagged the need for ‘colour blindness.’

Each colour category is associated with the production method’s carbon emission levels.

Green hydrogen refers to zero carbon hydrogen produced using renewable energy and electrolysis – which is currently a high-cost production option.

Blue hydrogen uses natural gas paired with carbon capture technologies to produce low-carbon hydrogen.

And dirtier methods are often described as grey hydrogen, which is produced with natural gas without carbon capture, and brown or black hydrogen, which is produced using coal – and is the most carbon intensive.

Then there’s pink hydrogen which is generated with nuclear energy and turquoise hydrogen which uses a methane feedstock.

Simultaneous development the way forward

All these methods should be simultaneously developed if the hydrogen economy is going to scale up enough to decarbonise hard-to-abate sectors, according to California Fuel Cell Partnership executive director Bill Elrick.

“I don’t like the color scale because hydrogen doesn’t really have a color – you’re really trying to get at a carbon number,” he said.

Toyota Tsusho America senior manager Toru Sugiura said an exclusive focus on high-cost green hydrogen won’t generate the demand necessary for the fuel to popularise.

“The carbon emission component is important, but I think first, in order to make hydrogen as a common fuel, I think it’s very important that we start using hydrogen whatever the colour,” he said.

Sugiura also said it would be important to initially use various low-carbon hydrogen types “just to change the market.”

“Then gradually we can think about carbon levels and green levels,” he said.

“The important thing is to try not to move from 100 to zero carbon emissions.

“Gradually moving towards zero emissions is important to starting up.”

US already legislating hydrogen production tax credits

S&P flagged that the US is already on the way to blending the colours a bit.

California Senate Bill 439 was introduced earlier this year and would expand the definition of green hydrogen to include more clean production pathways beyond electrolysis to include the conversion of biomasses and other renewable gasses and liquids to hydrogen.

And Biden’s Build Back Better Act would award hydrogen production tax credit amounts according to carbon intensity levels – rather than method.

“The credit would offer $3/kg of hydrogen produced with 95% fewer emissions than that produced by steam methane reforming, or grey hydrogen, and between 60 cents/kg and $1.02/kg for hydrogen produced with between 40% and 95% fewer emissions than grey hydrogen,” S&P said.