녹색 수소: 우리 꿈의 청정 연료?

There’s no denying that when hydrogen is mentioned the usual reaction is “Oh! Isn’t it dangerous?” and, from the controversially portrayed events of the 20th century, this reaction is not surprising.

In May 1939, following a transatlantic flight, a German airship called The Hindenburg caught fire while mooring in New Jersey. Due to US restrictions on exporting helium, the airship had been inflated with hydrogen instead: a decision that has been blamed for the fatality of 36 of The Hindenburg’s 97 passengers and crew, despite much debate about what caused the initial explosion.

Then, during the 1960s, at the height of the Cold War between East and West, scientists in the US developed the nuclear bomb, nicknamed the Hydrogen Bomb, or ‘H’ Bomb, a nuclear weapon with far more destructive capability than the atomic bombs that had destroyed Hiroshima and Nagasaki in 1945, and the world trembled.

In the 21st century, however, hydrogen is now gathering a reputation as, potentially, an energy source of our dreams rather than the fuel of our nightmares. In June of this year, the International Energy Agency (IEA) submitted a landmark report to the G20 summit in Osaka, focusing on hydrogen’s potential to play a key role in a clean, secure and affordable energy future. The report noted that clean ‘green’ hydrogen is currently enjoying unprecedented political and business momentum with the number of projects around the world expanding rapidly, but why?

The benefits of hydrogen

With the effects of climate change now very much in the news, governments around the world have finally started to talk about change. The UK recently announced ambitious plans to end the UK’s contribution to global warming within 30 years by reducing greenhouse gas emissions to zero by 2050. Scotland even plans to beat this target, recently announcing legislation that will see the country’s aim to reach net zero by 2045.

Clearly, there is an urgent need for viable alternatives to carbon-based fuels to guarantee our future energy security and reduce the impact on our environment. ‘Green’ hydrogen, i.e. hydrogen derived by using renewable electricity to split water, can provide many benefits.

Hydrogen is incredibly versatile and, as either a feedstock or an energy vector, green hydrogen offers ways to decarbonize a range of sectors – including long-haul transport, space heating and industry (particularly fertilizer and steel). Hydrogen can be transported as a gas by pipelines, in liquid form by ship or road, or be transformed into heat and electricity to power homes and fuel for cars, trucks, trains, ships and planes.

Crucially, hydrogen is also the missing piece of the jigsaw in enabling existing renewable technologies, such as solar PV and wind farms, to provide a greater contribution than currently. Hydrogen gas has the highest energy density of any fuel, making it one of the leading options for storing and transporting energy from renewables whose availability is not well matched to demand. In addition, the stable chemistry of hydrogen also means it can store energy longer than any other medium.

What many people don’t realize is that much of the technology needed to provide this societal shift is already available and has been successfully delivered via several demonstration projects, including some excellent examples in Scotland.

Take the high road

Our Edinburgh-based company designs, installs, commissions and maintains fuel cell and hydrogen energy systems in the UK and Europe. In collaboration with Bright Green Hydrogen, Toshiba, and Fife Council, we delivered the Levenmouth Community Energy Project in Fife. The project demonstrated green hydrogen as a viable medium for energy storage, grid balancing, electricity generation, heating and transport fuel.

The facility produces compressed hydrogen through electrolysis of main water from surplus electricity. This hydrogen is generated by a 750-kW wind turbine and 160-kW solar PV system. An electrolyser creates around 100kg of hydrogen per day for the onsite hydrogen storage requirements, which is then used in a 100-kW PEM fuel cell to generate electricity for the microgrid at times when electricity demand is higher than the renewable energy generated.

Two further electrolysers, a 60-kW PEM electrolyser and a 60-kW alkaline electrolyser, each generate around 20kg of hydrogen for two vehicle refueling systems. This hydrogen is stored at 450 bar and then used to fuel a local fleet of 17 hydrogen-powered vehicles. Hydrogen also feeds a hydrogen boiler providing heat to one of the buildings.

Likewise, the island community of Orkney provides another example of how hydrogen technology can be applied smartly to solve local problems. Back in 2015, there was almost no hydrogen activity there. Less than four years later, Orkney is now seen as one of the leading examples worldwide of deploying hydrogen as part of a low carbon energy system.

The community is using stranded wind turbine networks to produce the hydrogen via electrolysis of water, then transporting it by trailer to supply a fuel cell to power ferries when they are dockside in Kirkwall: A hydrogen refueling station to fuel hydrogen-electric vans and a hydrogen heating system at a local school.

The challenges for hydrogen

Current hydrogen projects tend to have a high initial capital cost and, as climate and air quality benefits are not adequately valued, profits are recouped over a longer time period than incumbent polluting technologies. This prolonged the time frame, which often results in a lack of political will to green light projects that won’t bear fruit within the lifetime of a parliament.

We need to deploy at a far bigger scale than the multitude of “demonstration” projects delivered so far. The technology is ready, it just needs the commitment to deploy on a large scale to enable cost reductions, and automated production to be implemented by suppliers.

In the Netherlands, projects are being considered to create GW windfarms in the North Sea, feeding electrolysers on artificial islands. This, in turn, forces green hydrogen to be sent back to the mainland via re-commissioned natural gas pipelines.

As governments move towards decarbonizing the energy network, there are millions of jobs at risk in the traditional energy sector. By embracing green hydrogen solutions, we have a chance to manage the human impacts of a transition from a carbon-heavy to a carbon-light industrial economy and lead on this transition.

Now is the time to act, change our perceptions and embrace hydrogen as a key part of our energy future.