Performance evaluation of a novel zero-carbon-emission system for hydrogen-solar complementary power generation

In this paper, a novel zero-carbon-emission system for power generation, hydrogen production and energy storage is proposed based on the complementary utilization of solar energy and hydrogen. To cope with the solar variability and intermittence, three operational modes have been developed: hydrogen mode, solar energy-hydrogen complementary mode, and solar energy mode. Comprehensive energy, exergy, entropy, exergoeconomic and ecological analyses are carried out. The system performances under the irradiation conditions of typical days in four seasons are revealed, and the effects of critical parameters are studied. Performance maps are drawn to facilitate engineers in promptly selecting operational parameters. Results indicate that: compared with two analogous cases, the novel system exhibits favorable advantages in terms of thermodynamic and exergoeconomic. In hydrogen mode, the thermal efficiency and exergy efficiency of the novel system are 46.52 % and 47.26 %, respectively. And the novel system in solar mode has the highest hydrogen production rate at 598.37 kg/h and the lowest total product unit cost at 6.53 $/GJ. The solar power tower subsystem and combustion chamber have the larger exergy destruction rate and entropy generation rate. The main cost source of the low temperature regenerator and high temperature regenerator is exergy destruction cost. Parameter analysis shows that the increase of main compressor inlet temperature inhibits the thermodynamic and ecological performance of the novel system. There is the optimal compressor pressure ratio that can help the novel system get the best thermal efficiency, exergy efficiency, entropy generation rate and total product unit cost. This study provides theoretical reference for developing a flexible power plant that can maintain the reliable power supply in the future electric system with high renewable energy penetration.