The rapid growth of clean energy markets as a distinct asset class has attracted significant investor attention. This study examines the interdependence between G7 stock markets and clean energy indices, specifically Renewable Energy Generation (REG), Energy Efficiency (EE), Advanced Materials (AM), and Clean Fuels (CF). Using a state-of-the-art volatility connectedness network and Maximum Overlaps Discrete Wavelet Transform (MODWT), we investigate the quantile time-frequency connectedness among the markets. Our findings reveal strong volatility linkages among all markets, with the exception of Clean Fuels, which has the least connection. We also observe higher dynamic spillover effects under extreme market conditions than normal conditions, with the US market being the most important transmitter of spillovers under bullish markets. Additionally, we highlight the importance of considering the time-varying nature of connectedness, emphasizing the heterogeneity between short-run, medium-run, and long-run transmission. Our study's implications suggest that investors should consider the dynamic nature of spillovers and connectedness when constructing portfolios containing clean energy and G7 stock market assets. The results also imply that the US market's performance has a substantial impact on other markets under bullish conditions, and that Clean Fuels may present an attractive investment opportunity for diversification purposes due to its relative independence.

清洁能源市场作为一种独特的资产类别的快速增长吸引了投资者的广泛关注。本研究探讨了七国集团股票市场与清洁能源指数之间的相互依赖性，特别是可再生能源发电 (REG)、能源效率 (EE)、先进材料 (AM) 和清洁燃料 (CF)。使用最先进的波动连通性网络和最大重叠离散小波变换 (MODWT)，我们研究了市场之间的分位数时频连通性。我们的研究结果显示，除清洁燃料市场之外，所有市场之间都存在很强的波动性联系，该市场的联系最少。我们还观察到，极端市场条件下的动态溢出效应高于正常条件下的动态溢出效应，其中美国市场是牛市下最重要的溢出效应传导者。此外，我们强调考虑连通性的时变性质的重要性，强调短期、中期和长期传输之间的异质性。我们的研究结果表明，投资者在构建包含清洁能源和七国集团股票市场资产的投资组合时，应考虑溢出效应和关联性的动态性质。结果还表明，在看涨的情况下，美国市场的表现对其他市场有重大影响，而清洁燃料由于其相对独立性，可能为多元化目的提供有吸引力的投资机会。