Research On Integrated System Of Intermittent Renewable Power Generation–Hydrogen Production And Energy Storage

In recent years, renewable energy is developing rapidly, wind and solar energy have received particular attention due to their great amount. However, the grid connection of wind and solar plants will lead to the negative impact on the operation of power system, because of their inherent output intermittency. Peak load shifting control by energy storage system is regarded as the ultimate solution of this problem. Hydrogen energy storage system is built based on the process of ‘water electrolysis – hydrogen storage – hydrogen fuel cell power generation’, the energy conversion efficiency is considerable, and the whole process is environmentally friendly. Moreover, if the surplus electricity produced by wind and solar power plants can be used in electrolytic hydrogen production, a new way of large scale hydrogen production can be developed. Currently, most industrial hydrogen production still use the chemical hydrogen production method, which not only consumes fossil fuels, but also discharges pollutants and greenhouse gases, so it is significant to find an environmentally friendly way to produce hydrogen. Under this background, our paper proposed to build an Integrated System of Intermittent Renewable Power Generation – Hydrogen Production and Energy Storage, and did a comprehensive study on this integrated system from the view of both technology and economy.At first, our paper has summarized the main components of the integrated system, such as electrolyser, fuel cell and hydrogen storage system. The existing technical problems in the establishment of integrated system has also been discussed, and it was pointed out that, with the development of technology and the wide spread of industrial applications, these problems can be solved in the future.Then, our paper has made a detailed analysis about the whole economy of the integrated system using net annual value method. The analysis results showed that the lowest sale price of hydrogen can be regarded as the evaluation index of the integrated system’s economy. The lower the price, the better the economy of integrated system.In order to improve the economy of integrated system, our paper proposed an optimal dispatching method. The main idea of this method is setting the grid-connected power and hydrogen output flow of integrated system in each divided time period with the goal of minimizing the lowest hydrogen sale price. The math model of the optimal dispatching method has been built at first, based on the forms of objective function and constraint conditions, the solving algorithm is confirmed. Then the algorithm is verified through computer simulation.In the end, our paper has made the comparison analysis between the lowest hydrogen sale price of integrated system and chemical hydrogen production, comparison results showed that integrated system can be expected to compete with chemical hydrogen production in the respect of economy, the development prospect of the integrated system deserves anticipation.