Energy-free wood regulates building heat

February 03, 2026

Scientists at the University of Texas have created an innovative wood-derived material that helps regulate indoor temperatures without using electricity. This breakthrough provides a sustainable alternative to traditional heating and cooling systems, supporting the growing demand for energy-efficient building technologies.

The newly engineered material functions as a natural thermal storage system, using advanced phase-change technology to absorb heat during the day and release it after sunset. By operating independently of the power grid, it delivers consistent indoor comfort while reducing energy consumption.

“Our material works like a rechargeable thermal battery that stores heat when temperatures rise,” explained Dr. Shuang (Cynthia) Cui, assistant professor of mechanical engineering at the Erik Jonsson School of Engineering and Computer Science.

How phase-change technology improves energy efficiency

Thermal energy storage plays a vital role in balancing energy supply and demand. Phase-change materials (PCMs) capture excess heat from the environment during warmer hours and redistribute it when temperatures drop.

When incorporated into building materials, PCMs act as built-in temperature regulators. They melt as they absorb heat and solidify as they release it, helping stabilize indoor conditions and minimizing reliance on air conditioning and heating systems.

“In hot seasons, the material absorbs outdoor heat before it enters the building,” Cui noted. “With enough phase-change material installed, cooling systems may not be necessary.”

This passive temperature management significantly lowers electricity usage and enhances overall energy efficiency.

Why wood is the perfect base material

Although phase-change materials have been researched for decades, they have faced a major limitation: leakage. When PCMs transition from solid to liquid, they often seep out, making them impractical for large-scale construction.

Traditional containment methods involve trapping PCMs inside support materials, but these hosts add extra weight and reduce thermal storage capacity.

To solve this issue, researchers studied the natural cellular structure of trees. By removing lignin—the compound that gives wood its rigidity—the team created a lightweight, porous cellulose framework.

These microscopic pores were then filled with a specialized mixture of phase-change compounds and flexible polymer material. This combination prevents leaks while strengthening the wood’s structure.

The result is a durable composite that stores heat efficiently without sacrificing mechanical stability.

Proven durability through 1,000 thermal cycles

Laboratory testing demonstrated that the material withstood more than 1,000 heating and cooling cycles without leaking or losing strength.

“Many energy-storage materials weaken over time,” said co-author Dr. Hongbing Lu. “Our wood-based composites maintain both thermal performance and structural durability, making them ideal for long-term building applications.”

This level of reliability is essential for sustainable construction materials designed for decades of use.

Moving toward commercial applications

The research team is now working to refine the technology and prepare it for large-scale manufacturing. Their goal is to bring affordable, energy-saving temperature control solutions to residential and commercial buildings worldwide.

Co-author Gustavo Felicio Perruci emphasized that the project’s success was driven by close collaboration with national laboratories and academic partners, proving that environmentally friendly materials can evolve into practical engineering innovations.