Empirical evidence of improvements in material and carbon efficiency of crystalline silicon solar panels

The rapid global expansion of photovoltaics has renewed attention on the material and environmental implications of large-scale deployment. Improving material efficiency is essential to meeting climate targets by reducing resource use and embodied emissions. This study analyses changes in crystalline silicon photovoltaic (PV) module performance between 2008–2012 and 2020–2024 using specifications from 320 commercial products. The median power-to-weight ratio increased from 10.5 W kg^-1 to 19.1 W kg^-1 (82 % improvement), while the power-to-area ratio rose from 135.3 W m^-2 to 219.5 W m^-2 (62 % increase). The carbon intensity of module production declined by 72 %, from 0.61 kgCO₂/W to 0.17 kgCO₂/W. In 2024 alone, these efficiency gains avoided approximately 19.3 Mt of material demand and 201 MtCO₂ of emissions. Unlike model-based projections, this work uses real-world product data and links efficiency gains to avoided material use and implications for high-intensity materials such as glass and aluminium. The results show that advances in PV module design have enabled rapid capacity growth without proportional increases in resource and emissions burdens, underscoring the importance of decarbonising foundation industries and planning for end-of-life circularity.