Why is cost reduction in photovoltaics conducive to the development of hydrogen energy?
Hydrogen, the gas with the lowest density in the world, has a calorific value of about 140MJ/kg, which is more than twice that of traditional fuels such as coal and gasoline. The product of its combustion is water, which does not cause any pollution to the environment. At the same time, hydrogen is also the most abundant element in the universe, and the abundant water resources on the earth contain a large amount of hydrogen energy that can be developed.
?
The following methods are commonly used to produce hydrogen:
1.???? Hydrogen production from fossil raw materials
2.???? Hydrogen production from coal
3.???? Hydrogen production from water electrolysis
At present, the cost of hydrogen production from fossil energy and coal is generally 10.1-13.4 yuan/kg, the cost of hydrogen production from natural gas is 13.4-16.8 yuan/kg, and the cost of industrial by-product hydrogen is about 11.2-16.8 yuan/kg. The cost of hydrogen production by water electrolysis is still at a high level of about 16.8-33.6 yuan/kg, which is far behind other hydrogen production methods and does not have economic advantages. The cost of hydrogen production by water electrolysis mainly comes from the huge electricity consumption. Among the most mature alkaline water electrolysis hydrogen production equipment, the hydrogen production efficiency is about 5kWh/Nm3 (Nm3=one cubic meter of hydrogen), and the electricity cost accounts for about 80% of the total cost.
Since the high cost of hydrogen production by water electrolysis mainly comes from high power consumption, the key to reducing its cost lies in energy consumption: on the one hand, it is necessary to reduce the power consumption in the electrolysis process, which needs to be achieved through technical means; on the other hand, it is necessary to use lower-cost electricity as the raw material for hydrogen production, that is, renewable energy such as photovoltaic and wind power.
"Photovoltaic + green hydrogen" means that the electricity converted by solar panels is supplied to the electrolyzer system for electrolysis of water to produce hydrogen. From photovoltaic green electricity to green hydrogen, the whole process is carbon-free and in line with the concept of green development.
At present, the world's largest green hydrogen project, the photovoltaic hydrogen production project in Kuche, Xinjiang, China, has a hydrogen production cost as low as about 18 yuan per kilogram. In some foreign countries or regions, the cost of photovoltaic power generation has even been as low as US$0.01-0.12/KWh. The development of photovoltaic green hydrogen in the local area will be more economical.
And with the continuous advancement of photovoltaic power generation technology, the cost of photovoltaic electricity still has room for a significant decline in the medium and long term. The industry predicts that by 2030, the cost of photovoltaic power generation is expected to drop by 25% to 0.1 yuan/kWh, and the cost of photovoltaic water electrolysis to produce hydrogen will at least drop by half, making it more competitive than fossil energy hydrogen production.
At the same time, the combination of "photovoltaic + hydrogen" also has a very positive significance for the development of the photovoltaic industry. At present, my country's photovoltaic installed capacity continues to increase, and the abandonment of light and electricity has also increased year by year, maintaining between 1% and 4%. A large amount of photovoltaic green electricity that cannot be connected to the grid has become "garbage electricity", affecting the economic benefits of enterprises, and it is urgent to find a reasonable way to store it. The development of photovoltaic water electrolysis to produce hydrogen can effectively consume photovoltaic power generation, realize the flexible conversion of electricity and hydrogen energy, effectively solve the phenomenon of abandonment of light, and avoid waste of resources.