Using solar energy during the night is now becoming possible thanks to new research published in ACS Sustainable Chemistry & Engineering. Scientists have developed a method that uses high-tech combination of paraffin wax and sand, which allows storing of heat from the sun and makes it available to use when the sun has set or during cloudy days.
The team led by Benxia Li created a special type of materials called “phase-change” materials or PCMs. These can store, release and absorb energy by switching between solid and liquid phases.
The team outlined some of the numerous applications of the materials. Besides the already mentioned solar energy storage, these materials can act as greenhouse gas regulators, and even they can control heath of military clothing.
Because currently existing PCMs are easily flammable, the team had the aim to find an alternative material that can meet all requirements, and they found the paraffin.
The material was chosen because of its properties to absorb heat, melt and release heat during solidification. Existing PCMs have disadvantages, such as the tendency to leak or catch fire, and Li’s team set out to find a better material.
To be able to use it as a PCM, paraffin has to be made into small spheres of silicone dioxide. The material becomes encapsulated, and it is characterized by a large surface area, which transfers heat, while it does not react with the environment and does not leak when switching between phases.
The team tested the material over 30 times, showing that at a temperature of 158 degrees Fahrenheit, the element does not leak.
The scientists are convinced that the storage capacity as well as the other properties of the material make it a potential energy storage material for various applications.