Today, fossil fuels are used to produce most of the hydrogen around the world. It leads to carbon emissions into the atmosphere.
Green Hydrogen technology has the potential to decarbonize the industrial processes used in oil refining, ammonia production, steel production, transport, and many more.
Many countries such as Chile, Japan, Australia, Saudi Arabia, Portugal have made a significant investment in green hydrogen technology with objectives of improvement in electrolysis technology, price reduction, and decarbonizing the industrial processes.
What is Hydrogen?
Hydrogen is the first element in the periodic table. It is odorless, colorless, non-toxic, and the lightest gas.
It generally occurs in the combined state in vast quantities as in oceans, sea, ice, lakes, rivers, and atmosphere.
Hydrogen is present in all animals, vegetables, and petroleum products (coal, natural gas).
If you want hydrogen, you need to separate it from its compounds, and doing so requires energy.
The process you adopt to separate hydrogen from its compounds determines its impact on the environment.
Hydrogen as an energy source
Once extracted, hydrogen can be stored as compressed gas or cryogenic liquid (stored in its condensed form).
It has one of the highest energy densities per unit mass.
With one of the highest energy densities per unit mass, hydrogen releases 120 kJ to 140 kJ of energy when 1 kg of it is burned.
It has applications in many sectors that can be divided into 3 broad categories:
The primary use of hydrogen is in fertilizer production, steel production, and hydro-cracking (the process of converting heavy fuel into kerosene, diesel, naphtha, and other high lubricating oils under high-pressure hydrogen).
What is Grey Hydrogen?
Natural gas is currently the primary source of hydrogen production. Most of the hydrogen is produced through Steam Methane Reforming (SMR).
Natural gas contains methane that is made to react with steam under high pressure to produce hydrogen.
But in this process greenhouse gases such as carbon-monoxide and carbon-di-oxide is also produced.
In addition, some methane leaks out in this process and gets dispersed into the atmosphere.
This leakage further adds to global warming.
The hydrogen produced in the SMR process is called Grey Hydrogen as leads to the emission of greenhouse gases that have a disastrous climatic impact.
When you manage, control, and prevent the dispersal of carbon monoxide and carbon-di-oxide into the atmosphere through the carbon capture and control process, the same hydrogen produced is called Blue hydrogen.
Some of these gases always leak out into the atmosphere.
Why do we produce Grey Hydrogen?
The wide range of applications of hydrogen as a fuel and the fuel cost is the main components that drive the hydrogen production using natural gas.
Russia, Middle East, North America, Turkmenistan, Venezuela are the countries rich in natural gas reserves.
You can see the lowest gas prices in these countries and this is the reason for the low cost of hydrogen production through the SMR process.
Green Hydrogen: Why has its demand increased suddenly?
The wide applications of hydrogen as a fuel have resulted in a 300% increase in its demand in the last 4 decades.
This process has resulted in 830 million metric tonnes of CO₂ emissions each year (equivalent to the CO₂ emissions of Brazil and Italy combined), leading to global warming.
Before, we hit a climate disaster, the search for an alternate method has started that can produce hydrogen without greenhouse gases emissions.
And here comes GREEN HYDROGEN.
Water covers over 70% of earth’s surface and if we can extract hydrogen from it economically, it can meet the energy demands of the world and can drive the future economy.
Green hydrogen has the potential of reducing global warming by 2°C by 2050.
Hydrogen can be produced through the electrolysis of water
It is a process of breaking water molecules into hydrogen and oxygen using an electric current.
When we use renewable sources of energy like solar or wind to produce electric current, the hydrogen produced is called Green Hydrogen.
For that, we need a big electrolyzer and plentiful of electricity for breaking water molecules.
Solar electricity cannot be produced at night.
Therefore, in the daytime when sunlight is at its peak, the hydrogen generated through solar is in excess and it can be stored for later use.
Hydrogen produced by countries abundant in solar resources can produce excess hydrogen, store it, and can transport it long distances to the other energy-deficient regions.
Green Hydrogen vs. Grey Hydrogen
The different shades of hydrogen
a) Green hydrogen is generated by electrolysis of water (as explained above).
The current needed to break water molecules is produced by renewable energy sources such as solar or wind power.
b) Turquoise Hydrogen: The methane obtained from natural gas in split into hydrogen and separable solid carbon.
The splitting requires electricity and if the electricity is produced from the renewable energy sources such as solar or wind, makes this whole process carbon neutral.
c) Blue Hydrogen is produced through the SMR process and the green houses gases produced are stored through CCS (carbon capture and storage) process.
d) Grey Hydrogen is produced through the SMR process and the carbon emissions are released into the air
e) Brown/Black hydrogen is produced from coal brown coal and black coal.
The gasification of coal produces hydrogen and carbon-di-oxide is released.
Cost of making Green Hydrogen
Although, green hydrogen production is technically viable
But to make it come in the mainstream production, the economic feasibility is very important.
At present, green hydrogen costs $2.5 to $6 per kg, almost 2 to three times costly than its production using the SMR process ($1 to $3 per kg).
Energy giants are making efforts to reduce its production cost to $ 2/kg by 2030.
Top energy developers taken green hydrogen initiative
The top 7 energy developers have come together to decarbonize industries processes by accelerating the green hydrogen production 50 folds in the next 6 years to bring down its production cost to $2/kg
How solar can help in green hydrogen production?
Solar PV offers a clean and low-cost option of producing electricity for the electrolysis process.
With the advancement in solar technology and increase in demand, the solar electricity production cost is falling constantly.
Scientists are working to improve the efficiency of solar panels.
(We see solar panels are having efficiency as high as over 22%).
The improved technologies like Half-cut solar cell technology, Bifacial, Mono-PERC produce more power than before and people are more interested in solar installations.
More solar installations mean the solar cost will fall further and this process keeps repeating, resulting in us see some of the lowest prices of solar electricity in the future.
This cheap solar electricity is used for the electrolysis of water, it will improve the financial feasibility of green hydrogen.
The Challenges ahead
1) Although hydrogen is itself is a clean energy source but it occurs in combined forms, we need other energy sources to separate it from its compound, adding extra infrastructure cost to its production.
2) Hydrogen is a highly inflammable gas and even a small negligence can be disastrous to human life and material.
Therefore, the hydrogen production plants must be certified for the utmost safety standards.
3) It is difficult to store hydrogen either we keep it in compressed form or condensed it at lower temperature. This adds to the overall cost.
In addition, we need special tankers that can take condensed or compressed hydrogen form one point to another
4) There is a financial risk for the investors who are taking the first step in green hydrogen.
Government should structure the right financial tools such as loan amount, duration, payback period, etc specific to the investment in green hydrogen so that more private players come in and invest in this technology.
5) There is a need to allocate funds for technology development. More research is needed to improve the electrolysis process.
The cost of green hydrogen production is 2 to 3 times the hydrogen produced through the SMR process.
The solar PV technology has developed many folds in the last decade.
It has emerged out as one of the cheapest sources of electricity and we will see series of rounds of price fall in future.
Similar success can be replicated in green hydrogen through technology development and improved policies, we can witness more plants using Solar PV technology to generate electricity, producing green hydrogen.