Stefano Innocenzi SVP new energy business at Siemens Energy explains why green hydrogen will play a pivotal role in the energy transition.

Any lingering doubt that climate change is a clear and present danger has evaporated. The focus is now on how the world can mitigate against the effects of climate change as world leaders gather at COP26 in Glasgow, Scotland. According to the United Nations, storms, wildfires, droughts, and other extreme weather phenomena fuelled by climate change have hit 4.5 billion people in the past 20 years, and a study from the German insurance company Munich RE showed that the cost of these disasters in 2018 alone amounted to US$160 billion. The continued projections of damage caused by the emission of greenhouse gases are dire and incalculable: rising global temperatures, shrinking glaciers, warmer oceans, vanishing coastlines and increasing natural catastrophes. 

Curbing the greenhouse effect has become one, if not the most decisive factor for energy policies worldwide. To limit global warming to well below 2°C above preindustrial levels, the Paris Agreement negotiated at the 2015 United Nations Climate Change Conference requires zero net emissions by 2045 to 2060. One hundred and seventy-four countries signed the treaty, but political pressure in industrialized countries is mounting to increase the speed of transformation. In October 2018, the International Panel on Climate Change (ICPP) further reiterated the need for decarbonization. It recommended an even more challenging target of limiting global warming to 1.5 °C by the end of the century. So, it will be very interesting to see what happens at COP26 in the way of future targets. 

Green hydrogen is key 

Today, enormous efforts and investments have been made to increase the share of electricity from renewables in the power sector, up to 25 per cent globally in 2017, but these have had little impact on global carbon emissions. The power sector contributes to the global CO2 emissions by around 40 per cent. The remaining 60 per cent comes from other sectors such as transportation, buildings, industry, and others. In fact, greenhouse gas emissions have continued to peak year on year with a record increase of 1.7 per cent in 2018. 

Green hydrogen could be the key to making a real impact on decarbonization as we can convert renewable electrical energy into hydrogen and its gaseous or liquid derivatives through electrolysis and further synthesis processes. Using electrical current, water is split into oxygen and hydrogen – a 100 per cent CO₂ emission-free process. Being a key technology for the energy transition, the resulting green hydrogen can be easily stored and further used or processed in many ways.  

Sector coupling 

Sector coupling via green hydrogen has the potential to reduce primary fossil energy consumption by 50 per cent, even while power demand grows by 25 per cent. There are three key areas that hydrogen can influence throughout the energy transition, in mobility, power generation and industry. For mobility, synthetic fuels can be produced from hydrogen and CO2 for immediate application: e-Methane, e-Methanol, e-Ammonia, e-Diesel, e-Gasoline, or e-Jet fuel – ready for instant use. They can be blended gradually with fossil fuels until they fully replace these fuels as a primary energy source.  

For power generation, modern gas turbines can be operated with a mix of hydrogen and natural gas. Hydrogen can be cached, transported in gas grids and re-electrified in gas turbines, combined cycles, or fuel cell power plants. Finally, in industry, it has a myriad of uses where there is a large demand for heat. Here hydrogen can become the feedstock for petrochemical plants or energy hungry processes such as steel, cement, or glass manufacturing, providing the appropriate storage facilities are in place.  

Leveraging the potential of hydrogen 

Sectors that formerly developed independently could be linked in the future via hydrogen. This is the case in industry, mobility, or heating sectors. That is why we see hydrogen as a key enabler for sector coupling. Additionally, green hydrogen is a viable option to store excess electricity from wind or solar over longer periods and in huge amounts. It also makes green energy from remote regions rich in wind and sun available to energy hungry regions.  

Future for green hydrogen 

Demand for hydrogen will potentially further increase. Sector coupling and progress in fuel-cell technologies will foster the development of low-emission hydrogen technologies and unlock economic and technological value across the entire energy system. 

There is no doubt that green hydrogen will play a significant role in decarbonizing our environment, but it must become competitive. Apart from lowering the price of renewable energy, manufacturers need to design and build electrolysers on an industrial scale. This is a significant challenge which requires companies having delivered industrial scale manufacturing to play a key role.  

At the same time, we should not forget that we have also to leverage the capability of players in the industry who can optimize systems for fluctuating power. An optimal design combining the different elements like power system, island mode operation, storage, and hydrogen production is key to make project economically viable on the long term.  

We know that green hydrogen is on the COP26 agenda – now I am curious to see how efficiently the hydrogen economy will be fostered in the future.  

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