Hydrogel-coated paper cools solar panels without extra power
Editorial visualization for Hydrogel-coated paper cools solar panels without extra power📷 AI-generated / Tech&Space
- ★The system uses hydrogel-coated airlaid paper, water flow and interfacial evaporation
- ★Outdoor tests showed up to 14 C lower temperature and up to 16.8% relative efficiency gain
- ★Stable operation was reported with natural seawater, but scale and durability remain open
A SIMPLE LAYER AGAINST HEAT LOSS
Solar panels like sunlight, but not their own heat. As a PV module warms, part of its potential output disappears into material physics. A Vietnamese research team therefore tested a solution that sounds almost too simple: hydrogel-coated airlaid paper that removes heat through water flow and interfacial evaporation.
According to PV Magazine, the work involves researchers from Van Lang University and several Vietnamese institutions, and the technique was published in Solar Energy. The material is made through freeze-thaw steps: the paper is first frozen, then coated on one side with a PVA-based hydrogel solution, frozen again, thawed and washed.
In the lab, the team used small epoxy polycrystalline panels measuring 5.5 cm × 6.0 cm, with wet paper covering about two thirds of the surface. The paper edges were immersed in water tanks to maintain flow through the material. In the outdoor test, two identical panels were installed on a rooftop in Ho Chi Minh City at a 25-degree tilt.
The Vietnamese prototype uses water flow and evaporation, but industrial durability still has to prove the idea
Secondary editorial visualization for Hydrogel-coated paper cools solar panels without extra power📷 AI-generated / Tech&Space
THE NUMBERS ARE STRONG, THE SCALE IS UNKNOWN
The results are concrete. Under one-sun illumination, the system lowered panel temperature by 7 C in still air and by 14 C at a wind speed of 1 m/s. That translated into relative electrical efficiency gains of 12.8% and 16.8%. Author Vanthan Nguyen also cited about 14.6% more energy generation without any external energy input.
Seawater is the important detail. The system operated stably with distilled water and natural seawater at about 32 ppt salinity, without salt accumulation in the reported tests. That opens an interesting path for coastal and island solar installations, where freshwater is a poor cooling resource.
Caution is still required. The tested panels were small, and industrial use must survive UV exposure, dirt, salt, biofilm, wind, maintenance and water logistics across large surfaces. The technology is interesting precisely because it is not “smart”: it relies on cheap material and evaporation physics. But simplicity becomes an advantage only when the same layer survives months and years of work outside the laboratory rhythm.