In 2020, China proposed the goal of achieving carbon emission peaks by 2030 and carbon neutrality by 2060. For China, whose energy consumption structure has long been dominated by fossil energy, carbon trading and new energy are crucial for the realization of the emission target. By establishing a connectedness network model, this paper studies the static and dynamic spillovers between the Hubei carbon trading market, new energy stock market, crude oil market, coal market, and natural gas market in China, and draws the following conclusions: (1) the static spillover index of the carbon–energy–stock system is 3.57% and the dynamic spillover index fluctuates between 7.67% and 22.62%, indicating that the spillover effect of the system is low; (2) for the whole system, whether from a static or dynamic perspective, the carbon market always plays the role of net information receiver, while new energy is the net information transmitter; (3) the new energy stock market and the coal market always act as net information transmitters to the carbon market; and (4) the spillover effect of the system is asymmetric, wherein the system is more sensitive to negative information about price returns, and this asymmetry is much greater when the system is active.

To obtain the price return and price volatility spillovers between renewable energy stocks, technology stocks, oil futures and carbon allowances under different investment horizons, this paper employs a frequency-dependent method to study the dynamic connectedness between these assets in four frequency bands. The results show that, first, there is a strong spillover effect between these assets from a system-wide perspective, and it’s mainly driven by short-term spillovers. Second, in the time domain, technology stocks have a more significant impact on renewable energy stocks compared to crude oil. However, through the study in the frequency domain, we find renewable energy stocks exhibit a more complex relationship with the other two assets at different time scales. Third, renewable energy stocks have significant spillover effect on carbon prices only in the short term. On longer time scales, other factors such as energy prices, climate and policy may have a greater impact on carbon allowance prices. Fourth, the spillover effect of the system is time-varying and frequency-varying. During the European debt crisis, the international oil price decline and the COVID-19 pandemic, the total spillover index of the system has experienced a substantial increase, mainly driven by medium, medium to long or long term spillovers.

The power sector is one of the major contributors to China’s carbon emissions, and its low-carbon transformation is of vital importance to China’s long-term sustainable development. This paper aims to investigate the spillover effect between the carbon emission trading (CET) market and power sector in China from a systematic perspective. We adopted the recently developed method of connectedness network and rolling window approach, and found that: (i) during our sample period, the total static spillover index and the average of total dynamic spillover indexes were 60.5735% and 57.9704%, respectively, and the spillover effect of this carbon-power system was relatively strong; (ii) there is weak bidirectional spillover effect between the CET market and the power sector, and the CET market is a net receiver of the information from the power sector; (iii) the CET market may exert a relatively high degree of impact on the power sector occasionally; (iv) for regulated power companies, their interactions with the carbon-power system may be related to its total holding installed capacity and the proportion of renewable energy installed. This study provides implications for policymakers, company managers, and market participants.