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.”