Image Credit: petrmalinak/Shutterstock.com
Green Hydrogen Overview
Green Hydrogen production involves water electrolysis with electricity generated from renewable energy sources.
Electrolysis splits water molecules into hydrogen and oxygen, capturing and storing the hydrogen for use as fuel.
Electricity generated from renewable energy systems makes this process completely free from carbon emissions.
Why Does Natural Gas Need To Be Replaced?
Natural gas primarily consists of methane, creating carbon dioxide upon its combustion. On a par with gasoline's 21% share and coal's 25% share, natural gas accounts for 19% of worldwide emissions of greenhouse gases.
Approximately one-third of greenhouse gas (GHG) emissions come from using natural gas to heat our homes. This must be addressed to meet the Paris Agreement targets to reduce GHG emissions by 75% by 2035 and achieve net-zero emissions by 2050.
Obstacles Faced in Replacing Natural Gas with Green Hydrogen
Cost of production
Green hydrogen is approximately four to five times more expensive than natural gas.
In addition to the high cost of green hydrogen production, building an infrastructure for its delivery to thousands of future freestanding filling stations presents several challenges.
A new hydrogen pipeline network requires significant upfront capital expenditures, and the characteristics of hydrogen present unique challenges in the design of pipeline components.
Hydrogen has a lower energy density per unit volume than all other fuels, making it more expensive to store and transport to the point of consumption.
Utilizing green hydrogen to decarbonize heavy industry will necessitate an enormous amount of electricity. The only way to meet this demand is to accelerate renewable energy production. This will create significant infrastructure design challenges, such as prioritizing H2 pipelines and transmission lines. The expansion of this gas industry will have significant regulatory ramifications.
To ensure the rapid expansion of hydrogen infrastructure, permitting monetization, developing a tariff structure to encourage deferral of capital expenditures, and ensuring system-wide infrastructure planning will be necessary.
Compression of hydrogen gas
Gases are compressed to be transported economically; this is the main issue with hydrogen distribution. It requires approximately three times as much energy to compress the same quantity of hydrogen as natural gas.
This threefold increase in compression is costly and would necessitate the replacement of every compressor with a larger unit and three times stronger suction displacement.
Pipelines leakage and reactivity
Hydrogen has different qualities compared to natural gas; therefore, the amount of hydrogen fuel blended into current pipeline systems is limited. As hydrogen is the smallest and lightest molecule in the universe, it can readily leak out of pipes and other sections of the gas network designed to transport the larger methane (natural gas) molecules.
Hydrogen reacts differently with different metals. Therefore, it can weaken and corrode steel pipelines commonly found in high-pressure gas transmission systems.
Obsolescence of fossil fuel
By switching to H2, many fossil fuel assets will become obsolete. It will be necessary to repurpose these substantial amounts of underperforming assets through various financial incentives to prevent harmful side effects.
Using Natural Gas for Production of Hydrogen
Blue hydrogen is produced by steam reforming of methane (natural gas). The carbon monoxide released during this process is then captured and stored with the help of carbon capture technology. It is not a completely carbon-neutral fuel as all carbon emissions are not captured in this process.
Recent Developments in Green Hydrogen
Green hydrogen projects have multiplied five-fold over the past three years, and several projects are planned through 2030, with an estimated $500 billion in financing and subsidies.
A hydrogen economy has official road maps in Japan, Canada, and the EU.
The Hydrogen Shot initiative of the US Department of Energy aims to achieve $1/kg by 2030.
China's state-owned businesses have already unveiled enormous green H2 projects with 100 GW electrolyzers, considering the nation's 2060 net-zero goal.
Hydrogen energy systems are being tested as a partial replacement for natural gas in home heating in Germany, where the world's largest electrolysis production facility is under construction.
In the UK, scientists are working to replace methane with H2 in the gas pipeline network.
The H21 pilot project is being prepared by Northern Gas Networks in Leeds, UK. The ultimate objective of this project is the complete energy transition of the city's heating system from natural gas to hydrogen.
The Future of Green Hydrogen
Hydrogen has an extensive history in power plants and industries. This gas has been used in automobiles, airships, and spacecraft fuel cells since the early 19th century.
The decarburization of the global economy, a development that cannot be prolonged, will elevate the significance of hydrogen.
Government and industries must work together to pave the way for investors. Common international standards for safe transport and storage of large amounts of hydrogen fuel and for identifying the environmental implications of various hydrogen supplies will improve international trade.
Although green hydrogen is still too costly to be competitive with traditional sources of hydrogen and other fuels, the number of projects involving hydrogen has increased in the past year as investors bank on the chance that hydrogen prices will decrease.
If hydrogen’s production costs decrease by 50% by 2030, as the World Hydrogen Council anticipated, it could be an essential clean energy source leading to a more sustainable future.