From gray, to blue, to green hydrogen

Different this time?

As the world shifts away from burning fossil fuels to a low-carbon future, hydrogen is key to decarbonizing heavy industry, long-haul transportation, and heating systems.

It is also a solution to balancing supply and demand from intermittent sources of electricity generation.

Steelmaking, cement manufacture, and other industrial processes need high temperatures. Hydrogen, in some cases, is better able than electricity to deliver it.

On the roads, hydrogen fuel cells will power trucks and buses for long distances. Vehicles can be refueled as quickly as with diesel. In the not too distant future, hydrogen and captured carbon dioxide will be turned into carbon-neutral liquid fuels for aircraft, while hydrogen fuel cells will be common in planes flying short-haul routes.

In the built environment, a combination of hydrogen, electric heat pumps, and local heating networks will provide heating in the future. Countries with extensive gas networks must repurpose and modernize their systems for hydrogen, first blending it with natural gas before switching entirely.

Hundreds of terawatts of surplus renewable electricity a year can be stored in the form of hydrogen to manage seasonal fluctuations and provide electricity at peak times when the wind isn’t blowing or the sun isn’t shining. By using the existing gas grid infrastructure as well as salt caverns and depleted gas fields, large-scale, low-cost, long-term hydrogen energy storage is cost-effective. In Utah, a project is underway to build the world’s largest salt cavern hydrogen storage facility.

Scaling up, cutting costs

There are three main types of hydrogen production pathways. These are generally color coded as gray, blue, or green.

Hydrogen is already used in huge quantities to refine oil and to produce methanol, ammonia, and other chemicals. It is produced mostly from natural gas. But the carbon emissions from the process, called steam methane reforming (SMR), contributes to global warming. Hydrogen from natural gas is known as gray hydrogen.

Capturing the carbon dioxide from the SMR process and using it to produce sustainable fuels or chemicals, or storing it in depleted gas fields offshore, is called blue hydrogen.

Green hydrogen is produced using renewable sources or nuclear power in an electrolysis plant that splits clean water into hydrogen and oxygen.

Up to now, cost has been the main obstacle to the widespread use of blue or green hydrogen. But given the scale of current investment in hydrogen, that is about to change. The Hydrogen Council is forecasting a 60% reduction in the cost of producing hydrogen by 2030.
Scaling up production of blue and green hydrogen is key to reducing costs and creating a virtuous circle of growing demand that fuels lower costs for components and distribution. As more production facilities open, shorter supply lines will cut costs further, while the huge global expansion of renewable power over the next decade will see the cost of electricity decline and make green hydrogen cost-competitive.

Moving forward

Solar and wind required government support in the form of incentives and subsidies to reach scale and trigger plummeting costs.

The rollout of hydrogen generally, and carbon capture technology to enable the production of blue hydrogen, will also need government backing.

The potential benefits of doing so are huge, and not just in reducing carbon emissions. Decarbonizing heavy industry will safeguard high-skill, high-value jobs in industrial heartlands, while thousands of new jobs will be created in the fuel cell, carbon capture, hydrogen infrastructure, and equipment supply chains.

A cleaner energy system in which hydrogen is a core component will also improve health outcomes in many communities, particularly in congested urban areas and industrial regions where poor air quality is a major cause of respiratory ill health.

The shift to hydrogen, both blue and green, must come quickly. If not, countries’ 2040-2050 net-zero ambitions will amount to nothing but "hot air."