Researchers announced on Apr. 19 that they have developed a new solar energy material made from wood, which can generate electricity even after the sun has set. The team modified balsa wood at the nanoscale to absorb sunlight, store it as heat, and continue producing power in darkness.
The innovation addresses a key challenge with traditional solar panels: their inability to produce energy when there is no sunlight. Most existing systems rely on separate storage units, leading to energy loss during transfer between components. By integrating all functions into one material, this new approach could increase efficiency and simplify design.
To create the ‘solar wood,’ researchers first removed lignin from balsa wood to make its natural channels more porous. These channels were then coated with black phosphorene for converting sunlight into heat and further treated with tannic acid and metal ions for better light absorption and protection against oxidation. Nanoparticles were added for additional light capture, while hydrocarbon chains provided water resistance. Stearic acid was used inside the channels to store thermal energy by melting when heated and releasing it gradually as it solidifies, allowing for continued electricity generation after sundown.
According to the study published in Advanced Energy Materials, “the resulting wood product integrates flame retardancy, superhydrophobicity, and antimicrobial activity, thereby mitigating dust adhesion and microbial colonization that would otherwise deteriorate the outdoor photothermal performance.” The researchers described their work as “a scalable and environmentally friendly wood-based platform for advanced solar thermal energy harvesting.” Other teams are also exploring ways of generating power without sunlight using water or even outer space.
With growing concerns about climate change and pollution from conventional energy sources, materials like this could have broad applications in sectors such as construction. The research team said their next focus will be on scaling up production of the new material.
