Renewable energies are becoming more and more popular, by force and by love. According to the IEA, in the next 4 years they will constitute 95% (ie almost all) of the increase in global energy capacity.
The turning point, apart from the climate change, is an economic one: renewables are becoming less expensive than fossil fuels. And this for unsuspected times already, that is, those that preceded the current geopolitical crisis. The current options (compatibly with the place of installation and local regulations) are now known: solar panels on the roof, small wind or hydroelectric power systems, heat pumps. However, other systems are emerging that you may not know and you could consider for a more sustainable home. One of these? The solar paint.
Solar paint, progress in the world

How about a paint that allows you to get energy from all surfaces hit by the sun, including the facades of a building? Not bad, and could even work in conjunction with classic roof panels to maximize efficiency.
There are currently three laboratories in the world that study three different types of solar paint:
- Quantum dot colloidal solar cells (University of Toronto) - This photovoltaic paint is composed of light-absorbing nanoparticles, distributed on a special film. These nanoparticles, called quantum dot they can produce an electric current due to their semiconductive properties. Researchers are working on it to increase its efficiency and durability.
- Perovskite solar paint (University of Sheffield) - Perovskite is a semiconductor that absorbs light and can also transform solar energy into electrical energy. The British team found a way to spray liquid perovskite cells onto surfaces: yes, "spray" solar cells. In the future, this system could make all surfaces, including glass windows, "energetic". A subsequent research from MIT in 2019 (here it is) has improved the electrical conductivity of this solar paint by 10 times.
- Solar Hydrogen Collecting Paint (Royal Melbourne Institute of Technology) - This solar paint uses a compound called synthetic molybdenum sulfide, which absorbs water from the air and also acts as a semiconductor, using the energy of sunlight to split water atoms into hydrogen and oxygen. Hydrogen is then used as a renewable energy source. Researchers they are optimizing methods to mix this compound with titanium oxide particles: they could create a paint that absorbs solar energy by generating hydrogen.
Solar paints aren't on the market yet and don't have the efficiency of silicon-based solar panels, but as labs perfect the invention you can give your home a coat of reflective paint. It already exists, was developed in 2020 and it is so "super white" that it can cool a surface below the surrounding air temperature.