For green hydrogen to become a major source of energy in the global energy mix, considerable investments are required. The objective is to reduce costs. In order to be able to substitute a part of the fossil fuels by renewable hydrogen. Focus on green hydrogen: the ins and outs of the hypothetical energy of the future.
Green hydrogen: the promise of carbon-free energy
Strictly speaking, hydrogen is not an “energy”, but an energy carrier allowing energy transfers. It is therefore a type of energy storage that interfaces the energy source and its final consumption. In this way, it reduces the problem of the intermittency of renewable energies (RE). It allows for the storage of surpluses to be re-injected into the electrical networks if necessary.
In addition, its “re-transformation” into electricity by means of fuel cells, can thus be used as fuel for electric motors available at service stations. It has, for that, a good calorific power: 1kg of hydrogen allowing to make 100km approximately. For the same weight, its calorific value is three times higher than that of gasoline.
It can also be used to produce heat or cold for industry. Also for heating and cooling of buildings. Finally, hydrogen and its isotopes are used as fuel for nuclear fusion.
75% of the mass of the Universe
The advantage of hydrogen (H) is that it is extremely common. It is even the most common atom since it constitutes 92% of the matter and 75% of the mass of the Universe. It is also the simplest atom: 1 proton and 0.1 or 2 neutrons depending on the isotope. Finally, it is also the lightest atom.
On the other hand, on Earth, hydrogen does not exist in its pure state. It is therefore always combined with other elements. Very often, it combines with oxygen (O) to form water (H2O).
Some notable disadvantages
On the other hand, hydrogen also has some disadvantages inherent to its properties.
In addition, its low density, around 90mg/m3, makes it difficult to store in large quantities in a mobile way. Its small size relative to other atoms also requires exceptional storage conditions. Also, its flammability is still an obstacle today.
Finally, the cost of producing green hydrogen is still very expensive. Too expensive to imagine a total substitution of fossil fuels within 10 to 30 years.
Reduce the cost of producing green hydrogen
According to a 2019IEA report, green hydrogen produced by water electrolysis is thus three times more expensive than methane steam reformation or thermolysis techniques, for example. Therefore, more than 98% of the hydrogen produced is from fossil fuels. It is then said to be “grey”.
A kilo of hydrogen at $1 in 2050?
However, in the long run, according to a study by BloombergNEF, the process of water electrolysis could become more competitive. By 2050, hydrogen from water electrolysis could cost between $1.6 and $0.70/kg. But to reach a selling price of $1 to $2/kg in 2050, investments must increase considerably.
Currently, storage in high-pressure cylinders remains the cheapest storage technique ($0.19/kg). Ahead of underground storage in salt caverns ($0.23/kg). The first technique does not allow the storage of large quantities, the second is not mobile.
Regarding transportation, the cheapest form of transportation is currently pipeline transportation ahead of ship transportation. But the use of the gas network raises many geopolitical issues. Just like the tensions around the Nord Stream 2 project.
Engage in strong policies geared towards the energy transition
In general, the production of green hydrogen can only be achieved at the cost of sustained energy policies. Up to 150 billion euros per year until at least 2030 according to BloombergNEF.
At the same time, the price of carbon must also evolve if we want to decarbonize the hard industries to decarbonize. According to BloombergNEF, the ton of CO2 equivalent will have to reach $50 for the steel industry. Or $116 for gas-fired electricity.
In the same vein, if policies follow, hydrogen for heavy road mobility could be cheaper than diesel by 2031. This would allow the democratization of the use of electric vehicles.
Massive development of renewable energies
Finally, to develop hydrogen, we also need a developed RE industry. However, for some countries, the geographical configuration does not lend itself to the deployment of solar panels, wind turbines or dams. This is the case for Germany, China, Korea and Japan, for example.
Conversely, in Brazil or the United States, hydrogen could be decarbonized and very competitive: less than $1/kg.
24% of the energy mix by 2050?
Eventually, if all the conditions are right, BloombergNEF estimates that 700 million tons of renewable hydrogen could be produced by 2050. This represents 24% of the energy produced in a scenario where global warming is limited to 1.5 degrees. But for this to happen, investments in renewable hydrogen must amount to more than $11 trillion by 2050.
Green hydrogen sales could also be worth $700 billion per year by 2050. But in this scenario, 31,320 TWh of electricity from renewable sources will be needed. This is more than all the RE currently produced in the world.
The condition of the future: incentive or even constraining mechanisms
Finally, hydrogen will only truly become the energy of the future if considerable political and economic incentive mechanisms are developed. Some of them, especially those concerning carbon dioxide emissions, should be legally binding. Together, these mechanisms will result in a concrete response to the challenges of energy transition.
Currently, many states and organizations have roadmaps in place to achieve carbon neutrality by 2050 or 2060. At the heart of these, renewable hydrogen tends to occupy a predominant place.
Especially since it motivates the development of RE on a very large scale. Or at least green and low-carbon energies like nuclear power. But also carbon capture and storage technologies.