Mixing industrial byproducts offers greener thermal energy storage

Phase change materials (PCMs) that absorb heat during the day and release it at night are a promising alternative to fossil fuel-based heating, a sector that accounts for 27% of energy consumption globally. However, the PCMs proposed so far are largely synthetic polymers produced from petrochemicals, but new works suggest that lignin, a byproduct from the paper industry, may offer a more stable and sustainable way to produce PCMs.