Future Of Carbon Free Fuel Using ‘Green Hydrogen’
By Batul Shakir
Present scenario of renewable energy in India
India is emerging as one of the largest producers of renewable energy in the world. As of 30th September 2020 ,36.17% of India’s installed generation capacity is from renewable sources (135 GW out of 373 GW). Development of wind power and solar has increased considerably and accounts for 38,124.15 MW (42.7)% and 36,050.74 MW (40.4%)respectively (source: Renewable energy in India - Wikipedia). Biomass power ,small hydro power and waste to power generation are among the other sources of renewable energy in the country. Although the energy produced can be deemed to be clean, the major issue in India related to these resources is the availability of land to lay the infrastructure for energy generation at a large scale which in turn is causing clearing of forest lands. This is where a new source of energy ‘hydrogen’ fits into the complex puzzle of renewables. Green hydrogen is a clean, low carbon fuel which is produced using water and in turn produces only water vapour when consumed in a fuel cell. Unlike other renewables, it can be used in places where there are issues with availability of wind and sunlight. So will hydrogen forever change the face of energy production and help us to decarbonize earth?
Color codes related to production
Hydrogen is the simplest of all elements and the most abundant chemical substance in the universe .The gas is color coded based on its method of production. Brown or black when made by gasification of coal and lignite, grey if it is made through steam methane reformation, pink when the electrolysis is powered by nuclear energy, white is the natural geological hydrogen found in underground deposits, blue when produced through steam methane reformation but emissions are curbed using carbon capture and storage, turquoise when produced through pyrolysis and finally the cleanest among all green hydrogen is produced mainly through electrolysis with no harmful byproduct. Nonetheless, the major condition to produce clean hydrogen is to use renewables like solar and wind to provide the electricity for production.
Common methods of production
Green hydrogen is seen as the ‘fuel of the future’. It's availability would never be an issue as it can be produced and transported anywhere in the world provided we have infrastructure to facilitate transport and storage. The most common methods employed today for production are electrolysis and thermal processes. Other methods can be biological, solar driven, wind driven etc. Electrolysis is separation of hydrogen and oxygen from water using an electrolyser. The hydrogen produced in this method is the form of energy that can be stored and transported for future use. All we need to produce green hydrogen is a large amount of water, electrolysers and plentiful supplies of electricity. Now this is where the abundant salt water can be put to use by employing sophisticated electrochemical techniques. Photobiological, photoelectrochemical, and solar thermochemical are examples of solar driven reactions. Biological methods of production include producing hydrogen through organic reactions performed by microbes like microalgae and cyanobacteria. Microbes can be grown even in waste water which is not potable and suitable for agricultural practices. Production through this method can be maximised by developing microbial strains that can use light and other inputs to increase the yield and improving the metabolic pathways and enzyme efficiency involved.
Uses of green hydrogen
Green hydrogen has a wide range of small scale to large scale applications ranging from use in heaters at home to powering fuel cells of ships. To begin with, we can use it to replace the industrial hydrogen that is made in bulk every year from natural gas. It can be mixed with natural gas and used for burning in thermal plants and district heating plants. It can be used as a precursor in production of synthetic fertilizers, producing hydrocarbons from synthetic ammonia, in Haber’s process, feedstock chemicals and various other chemical applications where hydrogen required is produced from fossil fuels. Furthermore, we will be able to reduce the cost of transportation by using fuel cells in heavy trucks, cars and ships .However, sectors like aviation and steel industry which have tremendous fossil fuel requirements cannot completely depend on green hydrogen at present but can use this coupled with other renewables to shift to cleaner energy sources.
Transport and storage
The transportation part is crucial owing to the high flammable property of the gas. It consumes a lot of space and brittles steel pipes and welds posing high leakage risk. However, the transportation may not need an entirely new infrastructure as the pipelines used to transport natural gas can be put to use up to some extent. The gas can be liquified, compressed and can be converted to a basic compound containing hydrogen (eg. Lithium borohydride) that is not as flammable as pure hydrogen. By road it can be delivered in cryogenic liquid tanker trucks or gaseous tube trailers. Storage can be done by storing the gas underground for a period of time and then piped on demand to power anything from ships to steel mills. Hydrogen is not new to us as it is already used in industries. So technical problems related to storage and transport are already being tackled.
(Source: A. Demirbas (2007) Storage and Transportation Opportunities of Hydrogen, Energy Sources, Part B: Economics, Planning, and Policy, 2:3, 287-295, DOI: 10.1080/15567240600629419
Cost of green hydrogen
Another challenge with green hydrogen is its production cost. This issue arises mostly due to the capital required to build efficient electrolysers. At present the cost is between 2.95USD (219.59 INR) - 6.49USD (483.223) per kg. However, the rates are predicted to decrease to 0.8USD - 1.6USD per kg by 2050. While including the cost of storage and pipeline infrastructure ,the delivered cost in India can fall to 2USD per kg in 2030 and around 1USD(74.4INR) per kg in 2050. Several Chinese manufacturers have succeeded in making electrolysis systems to create hydrogen from renewable energy at costs up to 80% lower than estimates from a few years ago.
Increasing taxes on carbon dioxide emission can trigger the major industries like the steel industry to move towards this cleaner fuel. Low cost production can be possible by involving solar and wind energy in the manufacturing process. In addition to this, since the cost of solar and wind has eventually dropped by few notches, hydrogen can be made affordable too as it’s demand increases.
I believe that hydrogen is an assuring and a powerful alternative because of its versatility. Our current renewable energy sources have already paved a path for hydrogen to emerge as a game changer in our goal to tackle climate change and decarbonization. Nevertheless, we need to proceed beyond electricity to cleaner carbon free fuels to meet the zero emissions target. No one or two source of renewables can be enough to suffice our need for energy but when the available resources will be used in conjunction, we will be able to come to grips with curbing the major environmental issues faced today like deforestation, climate change, pollution before the situation gets out of hand. At a small scale level, these clean energy sources can be encouraged to be used in households and small scale industries to realize a possibility of enormous change at a large scale. Alongside, oil and gas firms and renewable energy developers are viewing hydrogen as a potential market so considerable investments and development can be expected. In spite of the uncertain outlook of the hydrogen economy at present, I think we can progress towards making it the best alternative to fossil fuels by enforcing carbon prices and emission policies. In my opinion, hydrogen has exceptional potential to modify the energy situation at present and developing countries like India should definitely consider this to boost up the economy as well as restraint the ever growing demand of non-renewable resources that are bound to deplete in near future.