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Speaking at the Conservative party conference, UK Prime Minister Boris Johnson pledged that offshore wind farms would generate enough electricity to power every home in the UK by 2030, also announcing upgrades of £160 million to ports and factories for building turbines to help the country “build back greener.” However, scaling up to the envisioned 40GW of offshore wind generation will require investments of about £50 billion. The UK needs to include hydrogen in its journey to net-zero emissions. 

Also part of Johnson’s plans are a focus on hydrogen-fuelled trucks, trains and aircraft, retrofitting homes and spending more money on carbon capture and storage technology. Longer-term goals include expanding to other sectors the use of hydrogen as a source of power in the UK.

This is because moving to wind power and away from fossil fuels is not that simple. Some uses of gas cannot be replaced by renewable power; gas is used to both back up renewables and power heavy industry and problems with intermittency and intensity persist. Concerns arise when on a still, cloudy day, solar panels don’t generate electricity and wind turbines don’t turn. Further, according to the Financial Times, batteries are not yet the answer- if London were to rely on batteries for just a week, it would need to buy every battery produced in the world for the next two years. 

Secondly, electricity is unable to provide the heat required for heavy industry. Cement kilns and steel furnaces- sectors which cause more than 20% of global emissions- operate at over 1000°C. Therefore, clean hydrogen would arguably be the best choice for replacing gas when taking into effect economics and emissions. When hydrogen is used as a fuel, only water is produced. 

Currently, the cheapest way of making clean hydrogen is by converting it from natural gas, and then capturing and storing the leftover carbon. This “blue hydrogen” eliminates 95% of emissions compared to gas used in power stations, furnaces and kilns. Norway has been utilising this form of energy for decades. 

You might also like: Can Blue Hydrogen Spur the Transition to Green Energy?

Further, by building on hydrogen infrastructure, it paves the way for 100% carbon-free “green hydrogen,” produced by electrolysing water with renewable power. However, both blue and green hydrogen are extremely expensive; blue hydrogen costs more than twice as much as natural gas. Energy providers will need to work with the government to share the costs.

However, with greater scale and technology, hydrogen may one day cost less than gas. 10 years ago, wind power needed high electricity prices, but projects such as Dogger Bank now compete head on with fossil fuels. The UK will need to implement the right incentives to power a clean economic recovery post-COVID-19 while reducing emissions closer to net zero. 

In recent years, “blue” hydrogen has attracted much attention from both policymakers and energy-sector firms alike, for its alleged potential in facilitating the clean energy transition while providing alternate revenue streams for traditional fossil fuel companies. These assertions are not without controversy, given criticisms of how “blue” hydrogen production perpetuates greenhouse gas emissions while side-lining its “green” counterpart. This article examines such issues in the wider context of clean energy transition.

Historically, much of the hydrogen produced is derived from fossil fuel combustion, with natural gas used as an input for approximately 75% of over 110 million tonnes of hydrogen produced annually. Waste carbon dioxide from this process is released into the atmosphere, earning such hydrogen its “grey” label. Its “blue” variety retains the same production technique, but aims to trap and store these carbon emissions underground using carbon capture and storage (CCS) technologies. There also exists “green” hydrogen, which is manufactured via electrolysis of water powered from renewable energy.

Several major stakeholders have announced plans to develop their capabilities in “blue” hydrogen. Notably, the Norwegian energy company Equinor hopes to install its production facilities in Hull within the UK, using CCS technology to extract and bury the resulting carbon under the North Sea, while OPEC nations are in the midst of discussing its potential exploration.

Simultaneously, criticisms have arisen over the dependency of “blue” hydrogen on natural gas, which subjects it to commodity price fluctuations and geopolitical risks. This comes before considering that technical viability and lifetime costs of CCS facilities remain wrought with uncertainty, while modern CCS technologies only capture between 71% and 92% of the carbon in steam methane reforming (production of hydrogen and carbon monoxide), falling significantly short of any ‘net-zero’ emissions targets.

You might also like: What is Green Hydrogen?

blue hydrogen blue hydrogen
Forecasted global production capacity of blue (top) and green (bottom) hydrogen by region, between 2020 to 2028 (Source: S&P Global Platts Analytics). 

Despite its shortcomings, “blue” hydrogen remains a beneficial, even necessary, option for the energy transition, since its “green” counterpart lacks both production capacity and cost-competitiveness in the short-term. As fossil fuel reserves can be utilised, energy giants would probably be more receptive towards “blue” hydrogen, possibly even funding research and development efforts instead of lobbying against it. By installing the necessary infrastructure and stimulating uptake of hydrogen-based energy technologies, “blue” hydrogen can set the stage for the subsequent emergence of its “green” counterpart, especially if renewable energy prices continue to plummet in the future. All avenues for improvement should be explored in constructing a more sustainable economy, rather than allowing the strive for perfection to impede progress.

blue hydrogen
Bloomberg New Energy Finance (BNEF) projections of the cost of producing green hydrogen, when compared with hydrogen derived from natural gas (Source: Bloomberg). 

Featured image by: Flickr

Green hydrogen is a clean burning fuel that eliminates emissions by using renewable energy to electrolyse water, separating the hydrogen atom within it from its molecular twin oxygen. 

How Is Green Hydrogen Made?

The process of electrolysis has to happen. This process requires water, a big electrolyzer and plentiful supplies of electricity. if this electricity comes from renewable sources, then the hydrogen is green; the only carbon emissions are those from the generation infrastructure. 

However, not much green hydrogen is currently being produced; it currently accounts for less than 1% of annual hydrogen production, according to Wood Mackenzie. 

A challenge lies in the relatively small supply of electrolyzers and compared to more established production processes, electrolysis is very expensive, so the market for electrolyzers is small. 

How Do You Use It?

Green hydrogen can be added to natural gas and burnt in thermal power or district heating plants. It can be used to replace the industrial hydrogen that gets made every year from natural gas. 

However, storing and transporting green hydrogen is difficult; the highly flammable gas occupies a lot of space and can make steel pipes brittle. Because of this, specialised pipelines must be built, which is costly, pressurising the gas or cooling it to a liquid. These last two processes are energy-intensive and undermine green hydrogen’s round-trip efficiency. 

How Expensive Is It?

The International Energy Agency put the cost of green hydrogen at USD$3 to $7.50 per kg, compared to $0.90 to $3.20 for production using steam methane reformation. 

The cost of electrolyzers must be cut to reduce the price of green hydrogen, but this will take time and scale. However, the IEA says that electrolyzer costs could fall by half by 2040, from around $840 per kilowatt of capacity today. 

Another problem is that green hydrogen requires very large amounts of cheap renewable energy because some is lost in the process of electrolysis. Shell says that electrolyzer efficiencies range from around 60-80%. 

It is likely that developers, like Lightsource BP and Shell, will build green hydrogen production plants with dedicated renewable energy generation assets in high-resource locations. 

You might also like: Offshore Wind Farms: An Ecological Problem or Environmental Solution?

Issues 

Although a consensus has been reached that the world cannot be “fully decarbonised in the long term without green hydrogen,” producing the quantities of green hydrogen that the world will need would require a massive amount of renewable energy as well. 

According to the International Renewable Energy Agency (Irena), the world will need 19 exajoules of green hydrogen in the energy system in 2050- between 133.8 million and 158.3 million tons a year. 

Annual growth rates of wind and solar are increasing, however it is nowhere near enough for the world to be in line with the Paris Agreement goals. “The share of renewables in the worlds’ total final energy consumption has to increase six times faster to meet agreed climate goals,” Irena wrote in a report last year. 

With this, many argue, particularly within the oil and gas sector, that meeting ever- increasing energy demands with solely electricity is not going to be possible.

The current argument for clean hydrogen is that the bulk of the required volume of energy will have to be produced by natural gas and CCUs, also known as blue hydrogen. 

Several oil majors are struggling for pole position in green hydrogen development. For example, Shell Netherland confirmed in May that it had joined forces with energy company Eneco to bid for capacity in the latest Dutch offshore wind tender to create an enormous hydrogen cluster in the Netherlands. BP’s solar developer Lightsource also revealed that it plans to develop an Australian clean hydrogen plant powered by 1.5 gigawatts of wind and solar capacity. 

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