The world is looking for clean energy opportunity, and the simple act of running electricity through water could provide one of the most transformative technologies on the horizon. This process — known as electrolysis — splits the H(ydrogen) and O(yxgen) of water into their separate gases. It’s the H side of that H20 equation which offers a potential promise to our future energy landscape.
However, the vast majority of hydrogen production today comes from fossil fuel and biomass
However, the vast majority of hydrogen production today comes from fossil fuel and biomass, where burning fossil fuels act as the foundation of a process to release hydrogen. This fossil fuel focus means that hydrogen production generates over 830 million tonnes of CO2 emissions annually — equal to the emissions of Indonesia and the UK combined.
If hydrogen is to deliver on the potential of a clean energy future, it will need to radically transform its method of production and promote significant expansion beyond use in traditional industrial segments.
The electrolysis equation
Electrolysis was first discovered in 1785 by Dutch scientist Martinus Van Marum, but it wasn’t until the 1800s when further experimentation by scientists William Nicholson and Anthony Carlisle refined understanding of this process.
Nicholson and Carlisle employed pioneering new battery technology to undertake these experiments, revealing the early interlinking of hydrogen and electricity technologies. 200 years on, supporters of this hydrogen production technique champion it as a green revolution. They argue it could transform domestic and industrial energy consumption in areas from heating to power generation.
Hydrogen use in energy is largely driven by the industrial sector, but supporters argue it could revolutionise transport, buildings, and power generation. Demand itself for hydrogen has grown more than threefold since the 1970s, with more than 70 million tonnes produced today.
Hydrogen’s sustainable synergies
Electrolysis as a primary source of hydrogen production remains vulnerable to significant cost constraints. Just 0.1% of global hydrogen demand today is generated through electrolysis. Yet as renewable energy costs continue to fall, the price proposition for clean hydrogen production through electrolysis becomes more convincing.
The cleaner a national or regional energy supply is, the greener electrolysis can be. If a national grid running on 80% fossil fuels is used to electrolyse water for hydrogen, the emissions benefits are far less than if a production facility is entirely driven by renewable power.
Today, fuel costs account for about 45% to 75% of the cost of hydrogen production. In the future, creating sites with dedicated renewable energy generation such as solar or wind presents the potential for a low-cost, low-carbon hydrogen production.
There are of course challenges with this transition. The International Energy Agency (IEA) estimates it would require 3,600 TWh of electricity to meet today’s hydrogen demand through electricity. That’s more than the total annual generation of the European Union. Meeting this need would represent a sweeping transformation of the energy landscape.
Beyond industrial use
Hydrogen is today primarily used in industrial processes, with oil refining, ammonia production, methanol production, and steel production dominating global demand. Hydrogen fuel has potential far beyond industrial usage however.
Clean hydrogen fueled cell cars offer real promise for a more sustainable future. Comparing the energy production chain for competing technologies, the the energy production chain for competing technologies, the U.S. Department of Energy estimates wind-powered clean hydrogen would produce just 36 grams of CO2 per mile compared to 220 grams of CO2 per mile for gasoline in comparable vehicles. There are over 10,000 vehicles powered by hydrogen fuel cells in operation globally today.
These technologies produce no greenhouse gas emissions from exhaust pipes, emitting only heat and water, significantly reducing urban pollution. These same technologies could transform the emissions burden of shipping, public transport, railways, and long-haul transport, while offering more limited but innovative opportunities in aviation. China already has plans to trial thousands of hydrogen trucks and buses over coming years.
Blending hydrogen with existing natural gas networks could also reduce the carbon footprint of buildings. This blended supply reduces the carbon emissions intensity of functions like water or central heating. In fact, UK is pioneering its first blended mix at a trial at Keele University in early 2020.
Another innovation gaining traction are dedicated hydrogen boilers for domestic homes. England’s H21 initiative aims to drive 100% hydrogen use in national gas networks through a pilot project covering almost 4 million homes.
Is a hydrogen future ahead?
The synergy between hydrogen and renewable power also creates a two-way opportunity. Not only could renewable power be utilised to generate clean hydrogen resources, but hydrogen fuel cell technology could also uplift renewable energy adoption.
Hydrogen could also serve as a cost-effective storage solution for variable renewable technologies, where excess electricity is diverted to generate electrolysis and used to power hydrogen fuel cells. This means that high levels of solar power generated during the day could be stored in hydrogen storage technologies, offering a source of power when network demand requires.
As renewable energy scales up in coming decades, hydrogen power offers a valuable opportunity for long-term and large-scale storage, avoiding issues such as battery degradation that creates difficulties for rival technologies.
This emerging opportunity is gaining real traction in global circles. The IEA estimates that there are around 50 targets, mandates, and policy incentives in place today to drive forward hydrogen adoption, with the majority focused on transport.
So is hydrogen a revolution in energy technologies? There are certainly indications that it could be, if the right steps are taken. This isn’t a new technology — electrolysis is a process we understood over 200 years ago. What’s become clearer in that time is our need to embrace low-carbon solutions. This potential has been further transformed by radical changes in the costs associated with renewably powered clean hydrogen solutions.
Hydrogen power technologies offer an intriguing potential to drive reductions in our global carbon emissions, transforming industry, transport, and power generation. It’s not there yet, but there are growing signs of a global drive to realise that vision.