Abstract Power-to-gas (PtG), as a promising technology proposed to store surplus renewable energy (RE), can hardly be commercialized for its low profitability. In this paper, three approaches are proposed in this paper to enhance the profitability of the PtG. Firstly, a cooperative union containing PtG is proposed and its sustainability analysis is undertaken based on Shapley Value method. Secondly, the PtG reaction heat, as an essential by-product of PtG which is valuable and therefore requires further study, is fully exploited for district heating in the operation of regional integrated energy system, which is solved by an improved SOCP method. Thirdly, a symbiosis cooperation mode is designed for wind power and PtG to enhance the benefit of PtG through optimization-based trading strategy, which is a MINLP model and solved by Big-M method. The results show that the daily profit of PtG is significantly increased with the cooperative union as the symbiosis cooperation mode can produce a 15.1% profit lift, meanwhile, exploitation of reaction heat can produce an 8.6% profit lift. Finally, our study reveals the conflict of interest between wind power and the cogeneration. A sensitivity study on the proportion of reaction heat used for district heating is performed to verify the mutually beneficial relation between PtG and the cogeneration. The findings of this paper can guide the commercialization of PtG.