Researchers in India have developed a new type of bead from paraffin and stearic acid. It absorbs heat from the sun during the day and then releases the heat at night. The new beads should work well in climates like the United States Southwestern states.
PhysOrg reports that the findings will be published in The International Journal of Renewable Energy Technology. Mechanical engineer Meenakshi Reddy of Sri Venkateswara College of Engineering and Technology, in Chittoor, Andra Pradesh, and colleagues are the authors of the article due out in the near future.
The paraffin and stearic acid beads work like phase change materials (PCMs) that store a lot of heat in a small form factor. When the beads are left in the sun, they absorb heat melting the mixture. At night, the beads release the heat stored during the day as the mixture turns solid again.
PCMs have a high heat of fusion and melt/freeze at a certain temperature. Heat is absorbed when the material melts and released when it freezes. Heated in the sun, the mixture of paraffin wax (which melts at about 37 Celsius) and stearic acid (a fat commonly used to make soap) becomes entirely liquid. However, as it solidifies it slowly releases the stored heat.
The research team has tested beads the size of 38 millimeters (about 1.5 inches) floating on top of a tank of water. Once manufactured, they might resemble the bath oil beads pictured above.
While the technology is not all that involved, it works well. People using these beads for heating would save energy and money with lower power bills. In areas where electricity is nonexistent, these beads can provide some badly needed warmth.
The ability to gather heat during the day and then release it slowly during the night is similar to the thermal properties of adobe bricks. Not everyone can afford an adobe dwelling so the beads offer a great alternative.
In climates like the American Southwest that can go from very hot day time temperatures to very cold at night, these beads would be an inexpensive way to heat small areas while cutting down on energy bills. No idea if the beads once they hit production will ever make it to North America. If not, it sounds like a possible business opportunity. License the technology and then manufacture the beads for those interested in staying warm while conserving energy.