Uncertainty Meets the Sun: The Role of ESG Uncertainty, US–China Trade Tensions, and Oil Shocks in Shaping Solar Energy Adoption

Motivated by the view that sustainability uncertainty, policy uncertainty, trade frictions, and oil-price movements can jointly shape the pace of clean-energy adoption, this study investigates the drivers of solar energy consumption (SOC) in the United States by focusing on ESGUI, EPU, UCT, and OP. The study employs monthly observations spanning 01/11/2002 to 01/02/2024 and highlights a significant upward trajectory in SOC with recurring seasonal fluctuations. To capture potential nonlinearities and regime-dependent effects, the study relies on Quantile-threshold Kernel Regularized Least Squares approach. This approach evaluates marginal impacts across SOC quantiles and explicitly assesses their statistical significance over the distribution. Specifically, ESGUI is positive at the tails but negative and strongest around the median, EPU is insignificant at the lowest quantile but positive in the middle and negative at the top, UCT is consistently positive and increasing toward higher quantiles, and OP is positive and significant across most quantiles with a stronger influence in the middle-to-upper range before weakening at the extreme upper tail. Overall, the findings highlight that sustaining US solar growth requires a combination of policy credibility, resilient financing, and rapid removal of grid and interconnection bottlenecks, so that uncertainty and external shocks do not translate into delayed deployment when the system is positioned to expand.