The increased interest in hydrogen energy, which has been observed recently, can be called the second wave in the formation of this energy sector. Let’s recall that the concept of hydrogen energy, which involves the substitution of fossil and hydrocarbon fuels for hydrogen, was formed in the mid-70s of last century. Its implementation was based on the use of high-temperature (about 700 – 900 ° C) gas coolant of nuclear reactors on fast neutrons in thermochemical cycles of hydrogen production from water. However, practical results have not been obtained for a number of reasons, and primarily due to the significant complexity of construction and operation of plants for industrial hydrogen production by thermochemical cycles. As for the reactors themselves, their operation was characterized by high technological danger. For this reason, the operation of the Superphenix reactors (France) was terminated after a major accident in Monju (Japan) and the construction was stopped in Clinch River (USA). The Chernobyl and Fukushima accidents put the lid on the matter, which strengthened the restrained attitude of a number of countries to nuclear energy in general.
Despite the failure of these projects, the world continued to actively develop the use of hydrogen in transport. Moreover, almost all developents were based on hydrogen obtained from hydrocarbons. The main attention in the creation of the hydrogen car was paid to the development of hybrid engines with electrochemical generators, i.e., fuel cells that use the reaction of hydrogen air oxidation. By mid-2005 there were 118 hydrogen filling stations in the world, 49 of them in the United States. However, these developments were demonstrative in their nature. For some time, the trend remained “afloat”, but later began to disappear, which greatly contributed to the development of electric motor cars, as well as the strengthening of environmental standards for automobile petroleum-derived fuels.
At the same time, a number of problems remain relevant today, and primarily, the problem of hydrogen storage. Its maintenance in the gaseous state in large quantities requires a pressure of at least 50 MPa, which is difficult and dangerous. Storing liquid hydrogen in cryogenic containers is also dangerous. Hydrogen easily penetrates through metal walls, forming an “explosive mixture” with oxygen, whose flash can occur due to a slightest spark. It should be borne in mind the hydrogen corrosion of metals, which leads to an increase in their fragility and loss of strength. Hopes for hydrogen storage in nanotubes did not come true, its accumulation was insignificant, just over 30%.
The reason for the “second wave” of hydrogen energy, apparently, should be considered large-scale measures aimed at implementing the provisions of the UN Framework Convention on Climate Change (1992) and the Kyoto Protocol (1997), which oblige developed and emerging countries to reduce or stabilize greenhouse gas emissions.
The practical implementation of these measures is carried out through the production of electric energy from renewable sources (RES), primarily, from wind and solar energy sources.
But what does it have to do with hydrogen energy? A slight digression is needed. It is known that one of the features of the energy system functioning is the uneven load of the network during the day and night. This problem is solved through the energy accumulation, mainly due to the use of pumped power plants – PPP (over 96% of the world’s electricity storage capacity – 184 GW of installed capacity). The use of renewable energy is often accompanied by instability of production capacity due to changing weather conditions. Prior to RES, instability was “overlapped” by existing water storage systems, but with the increase in electricity production from renewable sources, there is a need to build additional energy facilities that will “smooth out” this instability.
A number of publications are devoted to the discussion on this problem, among them let’s mention the work of Academician of the National Academy of Sciences of Ukraine M.M. Kulyk (Director of the Institute of General Energy of the National Academy of Sciences of Ukraine), T.P. Nechaeva and O.V. Zgurovets (both are the members of the Institute) “Prospects and problems of development of the integrated energy system of Ukraine in terms of its accession to the EU energy system and hypertrophic use of wind and solar power plants in its network” (The Problems of General Energy, 2019, issue 4 (59), pp. 4-12). In the authors’ opinion, the need to build additional capacities arises from the instability of energy production by RES facilities due to changing weather conditions.
And what about the surplus electric energy produced by RES (as time has shown, they turned out to be significant, because there is an incentive for it – the “green tariff”!)? The most acceptable solution was the use of such electricity to produce hydrogen by electrolysis of water as a virtually inexhaustible source of raw materials – let’s call it “green” source in accordance with usual terminology. Thus, the ideology of “green” hydrogen was largely formed as a result of large-scale construction of wind and solar power plants, and problems following the use of electricity generated in power systems as well. Otherwise, it is difficult to explain the need to create complex systems for hydrogen production, organize infrastructure for its delivery and further use (and this is a separate topic for discussion) – all instead of direct use of green electricity to effectively replace fossil and hydrocarbon fuels, which is fully consistent with the Paris Agreement on the carbon-free energy development.
Let’s evaluate some aspects of green hydrogen production.
According to the European Clean Hydrogen Alliance, the implementation of the EU’s Hydrogen Strategy envisages the production of 1 million tons of electrolytic hydrogen by 2024, which will require the installation of 6 GW electrolyzers. By 2030, it is planned to increase this figure to 10 million tons and install electrolyzers with a total capacity of 60 GW. At a cost of one electrolyzer of about 0.5 million euros, it is 3 and 30 billion euros per 1 MW of electricity consumed, respectively. It is clear that the reaction of electrolyzer manufacturers to these requests is very positive. For example, in Germany which is known for its large-scale developments in this field, the European company Enapter has announced its readiness to produce 100,000 electrolyzers per year at its new industrial site in the country. the British ITM Power and the Norwegian NEL are among the major manufacturers of electrolyzers.
It is interesting that the largest manufacturers of electrolyzers, such as Germany and England, have achieved world records for the share of electricity produced from renewable sources in its total production. By the end of 2019, these figures were 36.6 and 35%, respectively, or 224.1 and 113.3 billion kWh (according to the Statistical Review of World Energy 2020/69). Doesn’t it give us certain ideas?
Nowadays, the prospects of Ukraine as one of the main suppliers of “green hydrogen” to Europe are actively discussed. At the same time, it is intended to organize the production sites for 9.8 GW of its production by electrolysis by 2030. Why shall we do it in our country? After all, this requires the construction of new significant facilities. Moreover, we do not have the North Sea coast with relentless winds and we are not Spain (where they have many sunny days). That is why the efficiency of using the installed capacity of wind and solar energy (their utilization factor) is only 13%.
Isn’t it an open secret? After all, Ukraine pays the highest “green tariff” in the continent and in this regard the country is very attractive to national and, importantly, foreign investors.
The author of the paper has already discussed this issue in his publications. (See Mirror of the Week newspaper, №32, 2018. “Why and to whom do we pay the “green tariff”).
What is our situation? As of the beginning of 2020, our wind and power plants produced about 5 billion kWh of electric energy. The use of this amount in the country’s energy system saves about $ 200 million due to reducing purchases of coal (anthracite).
Suppose all this electricity is used to produce “green” hydrogen. Then with the consumption of 4.6 kWh of electric energy in electrolyzers in order to obtain 1 m3 of hydrogen, we get 1.1 billion cubic meters of hydrogen. When converted to natural gas (in terms of calories, if we channel it into a gas pipeline), it is 355 million cubic meters and a gain of about 106 million dollars. But that’s not all. It is necessary to buy electrolyzers, and this is more than 400 million euros just for their purchase, without taking into account the cost of infrastructure. And in the case of hydrogen pipelines, the costs are immeasurably higher. Then the question arises: what for shall we do it? In order to buy electrolyzers from foreign companies?
Let’s look further: the European capacities amount to 9.8 GW, as it is mentioned above, and if we take into account 13% of their use, then we get about 260 thousand tons of hydrogen.
At the same time, to obtain one ton of H2 by electrolysis we need 9 tons of distilled water (or about 20 tons of water from our water basins), and in total – more than half a million tons!
Ukraine, which is poor in water, has something to think about.
So, what shall we do: shall we expand the construction of RES facilities to supply European and national customers with “green” hydrogen or provide national energy systems with carbon-free electricity?
According to official data, Ukraine’s energy system can use a maximum of 7 GW of electricity generated by RES facilities, which is provided by existing hydro-accumulation systems (without taking into account the increasing capacity of the Dniester PPP). In the first half of 2021, the capacity of facilities for the production of electricity from renewable sources amounted to 9.2 GW (it increased by 8.3%!), which is 1.19 GW of electricity actually generated. That is, we have significant opportunities to increase the capacity of carbon-free energy. In addition, Ukraine has an extensive network of electric power lines.
Doesn’t it mean that we shouldn’t get involved in the green hydrogen epic? No, it doesn’t. But how?
For example, in Europe, there are active developments aimed at the use of hydrogen in industry and the utilities sector. A large-scale experiment is conducted in the United Kingdom: in Scotland, several hundred houses in Fife County are equipped with free hydrogen fuel boilers, boilers and kitchen utensils. In Ukraine, there are also industrial structures interested in autonomous supply of enterprises with gaseous fuel – hydrogen.
In July 2021, leading Ukraine’s research institutions in the field of production, transport and use of hydrogen and hydrogen mixtures (Ivano-Frankivsk Oil and Gas NTU, Gas Institute of NAS of Ukraine, National University “Lviv Polytechnic”, G.V. Karpenko Institute of Physics and Mechanics of the NAS of Ukraine, Naftogazgazavtomatyka LLC and Ivanofrankivskstandartmetrologiya State Enterprise) established the HYDROGEN research concern. Its activities are aimed at conducting and coordinating research on the impact of hydrogen when it is used in equipment, elements and materials of gas pipelines, as well as research on various aspects of hydrogen mixtures use in domestic gas appliances.
In different years, our institute carried out significant developments with the use of hydrogen-containing gases (oil refining, coke) in industrial furnaces. The Center for Hydrogen Technologies is established, research is conducted on transportation and storage of hydrogen in pipelines, and interesting results are obtained in the course of study of natural gas and hydrogen mixtures combustion in domestic gas appliances.
We could have done much more, but even with the still preserved scientific potential, the institute is experiencing significant staffing problems – the influx of university graduates has virtually stopped, there are difficulties with enrollment in graduate school.
The reason is extremely limited funding. But even today we are ready to offer new ideas and new developments related to green energy. The main thing is that they should be useful both to the world and, ultimately, to Ukraine.
Borys ILYENKO, Academic Secretary of the Gas Institute of the National Academy of Sciences of Ukraine
Svit newspaper, № 47 – 48, December, 2021