What is the cost of hydrogen production from electrolytic water?
In the interest of environmental protection, the industry is calling for the production of hydrogen from renewable energy sources. Although electrolysis of water can produce green hydrogen, it is expensive. So how expensive is hydrogen production from electrolytic water?
Common hydrogen production technologies include coal to hydrogen, natural gas and oil to hydrogen, and industrial by-product hydrogen. Electrolytic water to hydrogen technology is also more mature, and some cases have already entered the practical stage. In electrolytic water to hydrogen technology, the price of electricity is the decisive factor.
If the cost of hydrogen production from electrolysis water is decomposed according to the normal industrial and commercial sales electricity price, it should specifically include asset depreciation, operation cost and electricity, of which the cost of electricity will reach 70-80%, accounting for a relatively high proportion.
It can be seen that the cost of electricity accounts for a large proportion of the cost of hydrogen production by electrolysis, and it can even be said that the cost of electricity directly affects the cost of hydrogen, so the process of hydrogen production by electrolysis needs to reduce the cost of electricity as much as possible.
Other costs, such as depreciation and operating expenses, need to be reduced by technological progress and management improvement, and the overall percentage is relatively small.
Generally speaking, each Nm3H2 produced consumes about 3.5-5kWh of electricity. If the current market price of electricity is used as the cost of hydrogen production, the electrolytic water technology route is not competitive.
However, if it is possible to produce hydrogen with low-cost electricity, i.e., when the comprehensive cost of hydrogen production from electrolytic water is reduced to about 1 yuan/Nm3, this method is economically competitive.
In addition, considering the carbon emission reduction factor, electrolytic water hydrogen production has some social benefits compared with fossil fuel hydrogen production.
Based on the assumption that the hydrogen production capacity is 600 Nm3/h and the annual hydrogen production is 1.2 million Nm3, we make static calculations for the electrolytic water to hydrogen project and get the following results: the annual electricity consumption is 6 million kWh, assuming the electricity price is 0.5 Yuan/kWh and the hydrogen is sold at 4 Yuan/Nm3, and the annual gross margin is about 28%.
Further, when we lock different gross margins at 30%, 40% and 50%, we can also calculate the hydrogen price as a function of electricity price: for the same gross margin, electricity price is positively related to hydrogen price.
If the electricity rate is reduced to 0 Yuan/kWh, the hydrogen prices under the three gross rates are 0.57, 0.71 and 0.92 Yuan/Nm3, respectively.
The above calculation shows that the lower the electricity cost, the lower the hydrogen price and the more competitive the project is.
This low-cost electricity is usually difficult to obtain, but it is expected to be realized in the process of electricity consumption from abandoned wind and light, which is the core of the electrolytic water to hydrogen process route.
In general, the advantages of using renewable energy to produce hydrogen are: it can effectively absorb waste wind and light energy while reducing the cost of hydrogen production; the relatively high energy conversion efficiency of electricity to hydrogen (60% ~ 80%); and the use of renewable energy to generate electricity electrolytic water for hydrogen production is a low carbon process. The contradiction of unbalanced development of clean energy is becoming more and more prominent, especially the problem of clean energy consumption, which seriously restricts the healthy and sustainable development of the power industry.