Quantifying the accelerated diffusion and cost savings of global solar photovoltaic supply chains.

Solar photovoltaic (PV) is critical for achieving the 2030 global target of tripling renewable power capacity. Over the past two decades, the global supply chain has significantly reduced the cost of solar PV products enabling widespread adoption. However, many countries are now implementing decoupling measures to enhance supply chain security and boost local economies. Here we quantify the impact of decoupling measures on solar PV deployment and module costs in China, the EU, the US, and Japan, using a methodology that combines the learning curve with the Bass diffusion model. Our results indicate that decoupling measures could lead to a significant increase in PV module costs and a marked slowdown in global deployment due to the disruption of free flows of capital, technology, talent, and information. The global supply chain remains essential for addressing the climate crisis. Countries should balance growth, security, and climate objectives in their green industrial policies.