According to international experts, hydrogen that has been used for over two hundred years already is finally having a chance of success just because of its ecological purity.
Hydrogen contains 2.5 times more energy per mass unit, as compared to natural gas or gasoline. However, its very low weight implies a much lower energy density per volume unit in its gaseous form and in ambient conditions.
«Hydrogen has a number of valuable properties, two of which make it unique in the era of climatic change:
Green, Grey, Brown, and Blue Hydrogen
About 70 million tonnes of hydrogen are currently produced, but only less than 2% is produced in an environmentally friendly way — by water electrolysis, in which water decomposes into its constituents, hydrogen and oxygen, affected by electric current. If electricity is produced using renewable energy sources (RES), then it is «green» hydrogen, which is the ultimate goal of sustainably minded countries.
However, as usual, this is the most expensive technique, and now hydrogen is produced mainly from fossil energy sources, such as from natural gas by reforming it, then it is «grey» hydrogen (75%) because its unwanted by-product is CO2.
The remaining volume of hydrogen is produced by coal gasification and is called «brown»hydrogen.
On the way to «green» hydrogen, the concept of «blue» hydrogen is distinguished: Where greenhouse gases are captured by a CCS (carbon capture system) in producing «grey» or «brown» hydrogen.
How Much Does Hydrogen Economy Cost?
According to the IEA, the main line item in the «grey» hydrogen production is the cost of raw materials, from 45% to 75% of the prime costs.
So, as per experts' calculations, in 2018 the lowest expenditures on producing hydrogen from gas were slightly below $1/kg in Middle East, $1/kg in the USA, $1.7/kg in Russia, $1.7/kg in Europe, and $1.8/kg in China.
At the same time, using CO2 catchers within the scheme will increase the expenditures by about 50%:
Of course, the share of raw materials within the cost for gas-importing countries is higher than in gas-producing ones.
According to industry-focused studies, the use of emission entrapping techniques in hydrogen production can reduce it by 90%. There are currently 20 large CCS facilities operating worldwide (mostly in the US, Canada, and Norway) with a total capacity exceeding 35 million tonnes per year.
At the same time, according to the IEA, «green» hydrogen production will cost at least $4.5/kg, while the main expenditures will be related to generating electricity. Electrolyzers for «green» hydrogen production may have three techniques: Alkaline electrolysis, proton exchange membrane electrolysis (PEM), and solid oxide electrolysis cells (SOEC).
The most widely used and advanced technique is alkaline electrolysis characterized by relatively low electrolyzer capital costs (less expensive, since it is commonly used fewer precious metals as compared to other electrolysis techniques and with the relatively high efficiency, normally ranging from 55% to 70%).
Experts believe that «blue» hydrogen is likely to be the main conductor of low-carbon energy on a short- and medium-term horizon, until «green» hydrogen reaches cost parity.
IEA analysts note that, due to the reduction of renewable electricity costs, particularly solar and wind power, interest in electrolytic hydrogen is growing, and some demo projects have already been implemented recently.
Would all hydrogen be produced by electrolysis now, that would lead to the electric power demand of 3,600 TW*h, which exceeds the annual generation of electricity in the European Union, calculated the agency analysts.
When reducing the costs of solar and wind generation, construction of electrolyzers on sites having excellent conditions for renewable resources can be an inexpensive hydrogen supply option, even considering the transferring and distributing costs in transporting hydrogen from remote locations where renewable energy sources are used.
At the same time, the rising prices of fossil fuels will also contribute to the increase in the competitiveness of «green» hydrogen. While «grey» hydrogen was the cheapest hydrogen everywhere except China in 2020, Wood Mackenzie expects its costs to rise by 82% by 2040, mainly due to growth in gas prices. In Saudi Arabia and in the USA, «grey» hydrogen will still be the cheapest hydrogen until 2040, they believe.
According to WoodMac, the cost of «blue» hydrogen will have grown by 59% by 2040. «Success of «blue» hydrogen is associated with the success of CCS technology that suffers from high costs and project cancellations. As with «grey» hydrogen, the expected cost profile is largely determined by natural gas prices,» they believe.
Svetlana Kristalinskaya
Full text can be found at: https://oilcapital.ru/article/general/10-09-2020/vodorod-epoha-vozrozhdeniya