Hydrogen is the simplest element on earth and most abundant element in the universe. It is an energy carrier as it has high energy content per unit of weight. And it has the potential to become a mainstream energy technology and a key clean fuel source in the future that could also help reduce greenhouse gas emissions.
The development of hydrogen research and technology in the next few decades could make hydrogen a multi-billion industry in the United States alone, Jeffrey Rissman, Industry Program Director & Head of Modeling at climate policy think tank Energy Innovation, writes in Forbes. By 2050, the hydrogen industry could generate as much as US$170 billion in annual revenues and make combined profits of more than US$100 billion, if hydrogen demand as a vehicle fuel results in 5 percent hydrogen-powered vehicles on the road in 2050, and if hydrogen is made entirely from electrolysis—the process of splitting hydrogen from water using an electric current.
This scenario is one of three possible pathways for hydrogen that Energy Innovation examined. This is the ‘hydrogen demand plus electrolysis (HD+E)’ scenario.
This scenario assumes that hydrogen will be produced without greenhouse gas emissions and using electricity from renewable sources for the electrolysis.
The other two scenarios are ‘business as usual’, in which hydrogen is not expected to be a game-changer, and ‘hydrogen demand’, where hydrogen demand in cars and industry is similar to the HD+E scenario, but 95 percent of hydrogen will still be produced from natural gas.
In the HD+E case, emissions could be reduced by as much as 120 million metric tons (Mt) of carbon dioxide (CO2) equivalent annually in 2050. This would be comparable to removing 25 million passenger vehicles from U.S. roads, Energy Innovation’s Rissman says.
The HD+E scenario, however, contains one bold assumption—that hydrogen will be produced entirely from electrolysis with no emissions.
At present, hydrogen is typically produced from natural gas and coal—not exactly the cleanest alternative source of energy.
That’s why scientists call this type of hydrogen ‘grey’ hydrogen because its production is not zero emission.
According to the International Energy Agency (IEA), around 70 Mt of hydrogen are produced today in the world, 76 percent of which from natural gas and almost all the rest from coal.
In the U.S.—which produces nearly one-seventh of global supply—95 percent of the hydrogen is currently produced from natural gas. That’s not only because natural gas is abundant in the U.S.—hydrogen production from natural gas is currently a lot cheaper than from electrolysis.
In terms of consumption, nearly all of the hydrogen consumed in the United States is used by industry for refining petroleum, treating metals, producing fertilizers, and processing foods.
Globally, hydrogen use is also dominated by industrial applications, with the top four single uses of hydrogen being oil refining (33 percent), ammonia production (27 percent), methanol production (11 percent) and steel production via the direct reduction of iron ore (3 percent), IEA estimates show.
Global hydrogen production today is responsible for 830 Mt of CO2 emissions annually, equal to the annual CO2 emissions of Indonesia and the United Kingdom combined, the IEA says, noting that if hydrogen production were to become emission-free, hydrogen could really be a green technology .
That’s because hydrogen, unlike other fuel sources, is used to generate power using a chemical reaction rather than combustion, producing only water and heat as byproduct.
The so-called ‘green hydrogen’ produced from renewable energy sources has been a promising concept but no breakthrough in this field has taken place yet.
But scientists are already developing various technologies to find a cheap, environmentally friendly, and feasible way to produce hydrogen—out of thin air and sunlight. The challenge is to turn those successful small-scale experiments into a large-scale cost-effective process.
The U.S. Department of Energy is studying and supporting various ways to produce hydrogen in a cost-effective and an environmentally friendly way. The DOE believes that there is potential to study hydrogen production from electrolysis, biomass gasification, thermochemical water splitting, photoelectrochemical water splitting, photobiological processes, and microbial biomass conversion.
In view of hydrogen’s potential to be a multi-billion industry of a zero-carbon energy source, Energy Innovation’s Rissman calls for more research into clean hydrogen technology:
“Even as the U.S. deploys proven, emissions-reducing technologies today – including solar power, wind power, and energy efficiency – we must invest in research and development, to ensure that hydrogen technology is ready to transform the last few, difficult-to-decarbonize elements of the energy system in the coming decades.”