Coconuts and lemons might hold key to efficient heating and cooling

In Sweden, a team at KTH Royal Institute of Technology has developed a construction material from coconuts, lemons, and modified wood that can help make heating and cooling homes exponentially more efficient. According to Peter Olsén, researcher in the Department of Biocomposites at KTH, 100 kilos of the material can save about 2.5 kWh per day in heating or cooling at an ambient temperature of 24 Celsius.

The team first created pores in wood by removing lignin. The pores were then filled with limonene acrylate, a molecule extracted from coconuts and lemons. When heated, limonene acrylate becomes a biobased polymer that stores and releases thermal energy.

“The elegance is that the coconut molecules can transition from a solid-to-liquid which absorbs energy; or from liquid-to-solid which releases energy, in much the same way that water freezes and melts,” says KTH researcher Céline Montanari. “Through this transition, we can heat or cool our surroundings, whichever is needed,” Olsén adds.

The findings were reported in the journal Small.