The development of hydrogen energy storage and its prospect

1. The long-term potential of hydrogen energy storage is huge
2. The cost of hydrogen energy storage has a large room for decline
   1. Renewable energy to make hydrogen energy storage
   2. Hydrogen energy storage by electrolysis of water
3. The transportation cost of hydrogen energy storage is high
4. Hydrogen energy storage enters long-term development track
5. Summary

At present, the mature methods of hydrogen production mainly include hydrogen production from fossil energy reforming, hydrogen production from industrial by-products, and hydrogen production from water electrolysis. Although carbon capture and storage (CCS) technology can effectively reduce the carbon emissions generated in the process of hydrogen production from fossil energy.

In the long run, only “green hydrogen” produced by electrolysis of water from renewable energy can achieve true zero carbon emissions. At present, hydrogen production from renewable energy accounts for a small proportion, and hydrogen production from fossil energy is still the main source of hydrogen energy storage making.

The long-term potential of hydrogen energy storage is huge

In the long run, hydrogen energy storage is expected to become an important form of electricity storage. Whether in the time dimension or the space dimension, the application scenarios of energy storage in the power system will be more abundant in the future, and the forms of energy storage will be more diversified such as thermal energy storage and flywheel energy storage.

We are still optimistic about the long-term potential of hydrogen energy storage as a form of energy storage. Hydrogen energy storage is mainly suitable for long-term, cross-regional energy storage scenarios. First of all, in terms of energy storage time, hydrogen energy storage basically has no rigid storage capacity limit, and can meet the energy storage needs of several days, months or even longer as needed. In addition, the transfer of hydrogen energy storage in space is also more flexible.

The transportation of hydrogen is not limited by the transmission and distribution network, and energy can be transferred across regions, long distances, and in no direction. Finally, the application range of hydrogen energy storage is also wider, and it can be converted into various energy forms such as electrical energy, thermal energy, and chemical energy according to the needs of different fields.

Hydrogen energy storage and electrochemical energy storage are more complementary than competitive. Hydrogen energy storage has great advantages in energy density and energy storage duration, but is relatively poor in energy conversion efficiency and response speed.

Therefore, hydrogen energy storage and electrochemical energy storage are not an either-or competition relationship, but complement each other and jointly support the smooth operation of the future power system.

The cost of hydrogen energy storage has a large room for decline

Renewable energy to make hydrogen energy storage

In addition to the reduction of the overall power generation cost of new energy, the peak-to-valley price difference in the future electricity market will continue to widen, and there will be more available low-price periods for hydrogen production from water electrolysis. As the proportion of new energy power generation increases, the instability of power supply will continue to rise in the future, and the range of price fluctuations in the power market will also expand.

For hydrogen energy storage, seasonal electricity price fluctuations will bring potential intertemporal arbitrage space. In the long run, there is a large room for improvement in the economics of hydrogen production from renewable energy.

In the future, the abandoned electricity from wind power and photovoltaics will become an important source of electricity for hydrogen production by electrolysis of water. In a power system with renewable energy as the main body, in order to ensure a stable power supply, the redundancy degree of installed capacity will be significantly increased, so in the long run, the amount of abandoned wind and photovoltaic will inevitably increase.

In the future, the consumption of abandoned wind and photovoltaic power will become an important application scenario for hydrogen energy storage, and this part of zero-cost or even negative-cost electricity can be used as an important power source for hydrogen production by electrolysis of water.

Hydrogen energy storage by electrolysis of water

Alkaline water electrolysis and proton exchange membrane water electrolysis are the current mainstream methods of electrolysis of water for hydrogen production. At present, the industrialization degree of alkaline water electrolysis and PEM is relatively high.

The former has the advantages of mature technology and low cost, but the quick start and load changing capabilities are relatively poor. The latter has the advantages of high efficiency and flexible operation, which is comparable to wind power, Photovoltaic is more adaptable, but the current cost is still higher.

The electrolyzer is the core part of the electrolysis water hydrogen production system. The electrolysis water hydrogen production system consists of an electrolytic cell and an auxiliary system, among which the electrolytic cell is the main place where the electrolysis reaction occurs.

From the perspective of cost structure, the electrolyzer accounts for about 40%-50% of the total cost of the hydrogen production system. In addition, the power conversion system, water circulation system and hydrogen collection system also account for a high proportion of the total cost.

Through the optimization of materials and design, the cost and performance of electrolyzers in the future have a large room for improvement. At present, the technology of alkaline water electrolyzer is relatively mature, and the main cost is the diaphragm and electrode (nickel-plated stainless steel). Catalyst lifetime in alkaline environment. The cost of alkaline water electrolyzers versus PEM electrolyzers is expected to reach below $100/kW in 2050, a drop of more than 60% from current levels.

In addition to technological progress, the improvement of industrialization will also make a positive contribution to the reduction of the cost of electrolyzed water hydrogen production system. On the one hand, with the expansion of the unit scale of equipment, the unit cost of power conversion, gas processing and other modules will be diluted.

On the other hand, the expansion of production scale will also reduce the manufacturing cost shared by a single device. Referring to the development history of photovoltaic and lithium battery industries, with the improvement of scale and degree of industrialization, the average cost of electrolytic water hydrogen production equipment is expected to enter a rapid decline channel. You will understand more about photovoltaic cell by reading our top 10 photovoltaic cell manufacturers in China article.

The transportation cost of hydrogen energy storage is high

The storage and transportation of hydrogen is difficult. On the one hand, hydrogen is the gas with the smallest density in the world, with low volumetric energy density and high diffusion coefficient; on the other hand, hydrogen has a low ignition point and a wide explosion limit, which also has extremely high requirements for safety during storage and transportation. .

Hydrogen storage and transportation can be divided into three ways: gaseous storage and transportation, liquid storage and transportation, and solid storage and transportation. Among them, gaseous storage and transportation have lower cost and faster hydrogen charging and discharging speed, but hydrogen storage density and transportation radius are relatively limited.

The hydrogen storage density of liquid storage and transportation is relatively high, but the equipment investment and energy consumption costs are relatively high. Solid-state storage and transportation are used in special fields such as submarines, and the whole is still in the small-scale test stage.

At this stage, the storage and transportation cost of hydrogen is still relatively high. The current cost of hydrogen transportation in different forms is roughly $2/kg, and the cost of hydrogen refueling at the terminal is as high as about $5/kg. Therefore, in order to achieve better economy at the terminal, the cost of hydrogen storage and transportation in the future still needs to be greatly reduced.

In addition to high-pressure gaseous storage and transportation, hydrogen pipelines are also an important part of the hydrogen storage and transportation system. Hydrogen pipelines can realize large-scale and normalized long-distance hydrogen transportation. As of 2016, there are more than 4,500 kilometers of hydrogen pipelines in the world, most of which are located in the United States and Europe.

In addition to the gaseous form, the liquid storage and transportation of hydrogen also has great potential for development. Since the critical temperature of hydrogen is about -240°C (no matter how much pressure is increased above this temperature, hydrogen cannot be liquefied), liquefying hydrogen requires a lot of energy (more than 15kWh/kg), and the current high cost is the storage and transportation of hydrogen liquid. main obstacle.

In addition to low-temperature liquid storage and transportation, liquid ammonia hydrogen storage or organic liquid hydrogen storage (LOHC) are also potential solutions. Hydrogenation and dehydrogenation are realized by the reversible reaction between hydrogen storage agents such as liquid ammonia, olefins, alkynes or aromatic hydrocarbons and hydrogen. , The energy consumption is relatively low, but the process and device are relatively complex, and there is basically no industrial application at present.

Finally, the hydrogen refueling station is also an important part of the hydrogen storage and transportation system. For small and scattered end-use hydrogen demand such as hydrogen fuel cell vehicles, hydrogen refueling stations are an essential transit link.

Hydrogen energy storage enters long-term development track

The hydrogen energy storage industry chain can be roughly divided into three links: hydrogen production, storage and transportation, and application, and the potential market space is huge. At present, the sources and applications of hydrogen are concentrated in the traditional refining and industrial fields, and “green hydrogen”, which has real long-term development prospects, is still in its infancy.

In order to truly take advantage of hydrogen as a clean energy source, a large amount of infrastructure investment is required in hydrogen production, storage and transportation, and downstream applications. Therefore, the launch of the hydrogen energy storage industry chain will bring long-term development space for a large number of equipment, components, and operating companies.

In recent years, the layout of various enterprises in the hydrogen energy storage industry chain has begun to accelerate. At present, the participants in the hydrogen energy storage industry chain include not only traditional industrial gas, petrochemical, coal chemical companies such as Linde, Air Liquide, Air Products, Sinopec, Shenhua, etc., but also car companies such as Toyota, Hyundai, Weichai Power, and Nikola. There are also Nel, Plug Power, Ballard, Yihuatong and other equipment manufacturers focusing on the field of hydrogen energy storage.

Summary

In recent years, the cooperation between enterprises in the field of hydrogen energy storage has increased significantly. On the one hand, China is currently the country with the largest hydrogen consumption, wind power photovoltaic installed capacity and car ownership in the world. There is a huge potential market space in the production and application of hydrogen, while some manufacturers have certain leading advantages in some key equipment and materials, such as TYCORUN Energy, which is odm best lithium battery manufacturer.

Therefore, the combination of technology and market can be realized through in-depth cooperation of enterprises, so as to better promote the large-scale and industrialized development of hydrogen energy storage.

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