Energy generation on every surface

Posted: February 07, 2025

Imagine if the walls of your home, your pants and jacket, or your electric vehicle could effortlessly generate clean energy, transforming surfaces once considered passive into vibrant power sources. This vision is inching closer to reality thanks to innovations in solar paint technology.

Last November, automaker Mercedes-Benz announced the development of a new type of solar paint that could dramatically extend the range of electric vehicles, potentially adding thousands of miles to their journeys.

But how close are we to the prospect of strolling into the nearest Home Depot and picking up a can of solar paint?

What is solar paint?  

Solar paint, or photovoltaic paint, is a paint that looks just like any other paint but contains a light-sensitive material suspended in it that makes it able to capture sunlight and transform it into clean energy. Solar paint has recently gained attention, but researchers have been working on a few different types for the last decade.

Perovskite solar paint: A leap in solar paint technology

In 2014, scientists at the University of Sheffield were the first to use a spray-painting process to fabricate perovskite solar cells.^[1] Perovskites, used in solar applications, have a specific crystal structure that can be optimized for better efficiency.

When sunlight hits the perovskite layer, it creates charges that need to move to another layer, often made of titanium oxide (TiO₂), which helps conduct them away. However, some of these charges can be lost during this transfer, which reduces efficiency.

University of Sheffield scientists enhanced perovskite solar cells by refining the crystal structure, boosting efficiency to 12.8% and achieving over 1,000 hours of operation under full sunlight.

Perovskite solar cells have since demonstrated comparable efficiency to traditional silicon solar cells, at least in laboratory settings. While most silicon solar cells have an upper-efficiency limit of around 29%, recent measurements show that perovskite solar cells have achieved efficiencies exceeding 26%. The latest perovskite-silicon tandem solar cells have reached an efficiency of 34.6%.

Hydrogen-producing solar paint

Meanwhile, researchers at RMIT University developed a solar paint containing synthetic molybdenum-sulphide, a compound that absorbs moisture like those tiny white balls of silica gel used in sachets to keep shoes dry, mixed with titanium oxide. This paint can harvest water vapor from the air to split water molecules and produce hydrogen, making it a promising tool for fuel production—even in remote, dry areas.

“Titanium oxide is the white pigment that is already commonly used in wall paint, meaning that the simple addition of the new material can convert a brick wall into energy harvesting and fuel production real estate,” said lead researcher Torben Daeneke in a press release.

Hydrogen is one of the cleanest energy sources and an essential piece of the energy transition puzzle. But it is only as clean as the electricity source used to split water molecules, which, to date, mostly comes from fossil fuels.

The idea of using sun power as an alternative energy source to produce hydrogen seems alluring. However, since their initial paper, published in the American Chemical Society journal in 2017, the team has not made much progress.

Quantum dot solar paint: A flexible future

Researchers at the University of Toronto have pioneered another promising technology.^[2],[3] Over ten years ago, they invented a new way to spray solar cells onto flexible surfaces using colloidal quantum dots (CQDs). These are tiny semiconductor particles, typically measuring just a few nanometers in size, that exhibit unique optical and electronic properties. Their small size allows them to confine electrons in a way that larger materials cannot.

CQDs are highly versatile and can be tailored for various applications by adjusting their size, shape, and composition. For instance, the color of light emitted by a quantum dot can be changed simply by altering its size; smaller dots emit shorter wavelengths (like blue), while larger ones emit longer wavelengths (like red). They are already used in optoelectronic devices, such as light-emitting diodes (LEDs), solar cells, photodetectors, and lasers.

These tiny semiconductor particles can capture sunlight and convert it into electricity, functioning similarly to traditional solar cells but with the added flexibility of being sprayed onto a flexible backing and applied like wallpaper.

While the efficiency of those first attempts to make quantum dot solar paint was around 8%, the most efficient quantum paints had reached about 18% in 2022.

Mercedes solar paint could boost electric vehicle range by many miles  

Mercedes-Benz is developing a solar paint that could significantly improve the range of EVs. This paint, which is only five micrometers thick and weighs just 50 grams per square meter, can be applied directly to the vehicle's bodywork like a thin layer of paste.

With an efficiency of 20%, an area of about 11 square meters—equivalent to the surface of a mid-size SUV—could generate enough energy to power the vehicle for approximately 7,500 miles per year under ideal conditions. The energy produced can be used to drive the vehicle or charged into its battery, even when the car is parked.

According to the Mercedes-Benz website, the paint is made from a combination of non-toxic, readily available raw materials and does not contain rare earth elements or silicon. The coating consists of several layers, including a conductive material, insulation, a solar-active material, and a translucent top layer embedded with nanoparticles that reflect specific wavelengths of sunlight.

“The innovative solar paint can be applied to the entire body surface, offering enormous potential for off-grid power generation. This means a longer range, fewer charging stops, and cost savings,” Niels Schreuders, Development Engineer at Mercedes-Benz AG, told Our Industrial Life. “The potential of solar paint extends beyond just charging electric vehicles. Excess energy could be fed into the home power grid, providing an additional renewable energy source for household use.”

The boundless potential of solar paint

Solar paint could transform unexpected surfaces into energy hubs—like roadways, which could power streetlights or clothing that could charge personal devices on the go. The adaptability of solar paint demonstrates its potential to redefine energy generation. The technology promises a future where nearly every surface could contribute to clean energy production, but to date it is still in an experimental phase, with researchers working to overcome challenges like efficiency, durability, and large-scale application. It might take several years of development and testing before solar paint becomes a practical, widely available product.

^{[1] A hole-conductor–free, fully printable mesoscopic perovskite solar cell with high stability, Science, July 2014
[2] Efficient Spray-Coated Colloidal Quantum Dot Solar Cells, Advanced Materials, November 2014
[3] Colloidal quantum dot solar cells on curved and flexible substrates, Applied Physics Letters, October 2014}