Researchers at the Massachusetts Institute of Technology (MIT) have developed a new technique to absorb and retain solar energy and use them on demand.
Professor, Dr. David Zhitomirsky of MIT said, "it's a material capable of absorbing photons (light) and storing their energy."
The spin coating process allows solar thermal polymer materials to settle from solution (Image Source: MIT).
Dr. Zhitomirsky is the head of the project and the first author to have a detailed article on these findings in Advanced Energy Materials. "This energy can be used as heat on demand, then recreated as a starting material and this can be done many times."he wrote in the scientific report.
Researchers claim that storing solar heat in the form of chemical changes (instead of just storing heat) is the solution to long-term and sustainable storage problems. Currently, no matter how effective the insulation methods are, heat will always be lost over time.
On the other hand, chemical storage systems can keep energy in a stable molecular structure until it is released. When needed, this energy source can be activated by heat, light or electricity.
"The absorption of light changes the shape of the molecules of this material. The energy of these molecules is higher than the original energy source, so when it returns to its original state there will be a source of heat. release to the environment"Dr. Zhitomirsky explained.
"And importantly, in this process the initial molecules can be recovered without degradation"Dr. Zhitomirsky added.
Image test of heat release. A heating element is used to provide enough energy to activate solar thermal fuel materials, while an infrared camera monitors the temperature. Electrically charged film (right) releases heat to allow higher temperatures than non-charged film (left) (Image source: MIT)
This process has foundations of polymer compounds, materials with reasonable cost and common production technology. Previously, research efforts on storage materials based on chemical properties were directed towards liquids, all of which have limited their applicability. In this new process, the storage material is solid.
Material production is a two-step process: The team uses azobenzen, which has been changed to molecular configuration when exposed to light, then a small amount of heat will bring these azobenzen back into configuration Initial and allow them to release previously stored heat.
The researchers changed the chemical composition of the material to improve energy density, create fixed membranes and the ability to react to heat pulses.
Solar thermal polymer film consists of three separate layers (thickness four to five microns per layer) (Image source: MIT)
In fact, these types of vehicles often have hot wires integrated into the rear windows because there cannot be anything that shields the driver's vision in the front glass. And this transparent polymer film will be made into a windshield that can melt snow.
Dr. Zhitomirsky added on the importance of this energy storage system:
"This is a great addition to solar harvesting. It is inexpensive and allows you to simultaneously plan and store energy without additional equipment"
"These materials can be used extensively in rural and developing countries, and they are also used in developed countries and cities, for example, integrated into clothing. ."