Engineered Wood: Storing Solar Energy Without Sunlight

Researchers have developed an engineered wood material capable of absorbing sunlight, storing it as heat, and continuing to generate electricity after the sun has set. This development addresses a primary limitation of solar energy: the loss of power generation during periods of darkness.

Traditional solar thermal energy storage often relies on stacking disparate materials. These systems typically use one layer to absorb sunlight, another to store the resulting heat, and a third to protect the system. Because these materials do not work seamlessly together, energy is frequently wasted at the boundaries between layers.

The new approach replaces these multi-part assemblies with an all-in-one system by redesigning the internal structure of wood at the nanoscale. This allows the material to function as a scalable and environmentally friendly platform for harvesting solar thermal energy.

Engineering the Internal Architecture

The research team utilized balsa wood as the starting material. Balsa was selected not for its physical strength, but for its specific internal architecture, which consists of aligned microtubes approximately 20 to 50 micrometers wide. These channels serve as a natural scaffold capable of holding materials and guiding heat.

Because raw wood naturally reflects sunlight and absorbs water, the researchers performed a delignification process. By stripping the wood of lignin—the component responsible for its rigidity and color—the team increased the material’s porosity to over 93 percent. This process effectively turned the wood into a highly porous sponge while maintaining its directional structure and exposing a dense network of reactive surfaces within the channels.

Following delignification, the researchers chemically engineered the inner surfaces of the wood. This method differed from carbonization, which is a common process involving the burning of wood.

Technical Implications and Scalability

By modifying the wood’s internal structure, the material can capture solar energy and store it as heat. This stored energy can then be used to generate electricity even in the absence of sunlight, overcoming the intermittent nature of solar power.

Our work presents a scalable and environmentally friendly wood-based platform for advanced solar thermal energy harvesting

Researchers

The researchers are currently working to ensure the system can operate at scale while maintaining desirable energy output. If the system proves successful, the methodology could potentially be adapted to other biomass structures and nanomaterials.

Such an evolution would lead to a new generation of solar power systems capable of managing, capturing, and storing energy autonomously within a single material structure.