To protect the environment, the industry is calling for hydrogen production from renewable energy sources. Electrolysis of water produces green hydrogen, but it is expensive. So how expensive is electrolyzing water to make hydrogen?

Common hydrogen production technologies include coal hydrogen production, natural gas and petroleum hydrogen production, industrial hydrogen by-production, etc. Electrolytic water hydrogen production technology maturity is also high, some cases have entered the practical stage. The price of electricity is the decisive factor in electrolysis of water to produce hydrogen.

If the cost of electrolytic water hydrogen production is calculated and decomposed according to the normal industrial and commercial sales electricity price, it should specifically include asset depreciation, operating expenses and electricity charges, of which the cost of electricity will reach 70-80%, accounting for a relatively high proportion.

It can be known that electricity costs account for a large proportion in the cost of hydrogen production from electrolytic water. It can even be said that electricity costs directly affect the cost of hydrogen, and electricity costs need to be reduced as much as possible in the process of hydrogen production from electrolytic water.

Other expenses, such as depreciation and operating expenses, need to be reduced through technological advances and management improvements, and the overall proportion is smaller.

Generally speaking, about 3.5-5kwh of electrical energy is consumed per production of 1Nm3H2. If the current market price of electricity as the cost of hydrogen production, electrolytic water technology route is not competitive.

However, if low-cost electricity can be used to produce hydrogen, that is, when the comprehensive cost of hydrogen production by electrolysis of water is reduced to about 1 yuan /Nm3, this method is economically competitive.

In addition, considering carbon emission reduction factors, hydrogen production from electrolysis water has certain social benefits compared with hydrogen production from fossil fuels.

Based on the assumption that hydrogen production capacity is 600Nm3/h and annual hydrogen production capacity is 1.2 million Nm3, we carry out static calculation of the electrolytic water hydrogen production project and get the following results: the annual electricity consumption is 6 million kWh, the electricity price is assumed to be 0.5 yuan /kWh, hydrogen is sold at 4 yuan /Nm3, and the annual gross profit rate is about 28%.

Furthermore, when we lock different gross margins at 30%, 40% and 50% respectively, we can also calculate the function relationship between hydrogen price and electricity price: at the same gross margin, electricity price is positively correlated with hydrogen price.

If the electricity fee is reduced to 0 yuan /kWh, the hydrogen prices under the three gross margins are 0.57 yuan, 0.71 yuan and 0.92 yuan /Nm3 respectively.

The above calculation shows that the lower the electricity bill, the lower the price of hydrogen, the more competitive the project.

Such low-cost electricity is often hard to come by, but it promises to be used in the process of wind and light dissipation, which is at the heart of the process route of electrolysis of water to produce hydrogen.

Generally speaking, the advantages of hydrogen production from renewable energy are: it can effectively absorb waste wind and light energy, while reducing the cost of hydrogen production; The energy conversion efficiency of electricity to hydrogen is relatively high (60% ~ 80%). Hydrogen production from water electrolysis using renewable energy to generate electricity is a low-carbon process. The contradiction of unbalanced development of clean energy is increasingly prominent, especially the problem of clean energy consumption, which seriously restricts the healthy and sustainable development of the electric power industry.