Turning Surfaces into Solar Power

The 3 Flavours of Solar Paint

1. Hydrogen-Producing Solar Paint

Developed at RMIT University in Australia, this paint absorbs ambient water vapor and, using solar energy, splits it into hydrogen and oxygen. It relies on synthetic molybdenum sulfide combined with titanium dioxide—akin to silica gel and conventional paint respectively—to facilitate this chemical reaction. The resultant hydrogen offers a clean and transportable energy source.

2. Quantum Dot Solar Paint (Photovoltaic Paint)

At the University of Toronto, researchers crafted paint using colloidal quantum dots—nano-sized semiconductors whose absorption spectrum can be tuned by adjusting their size. This enables efficient light capture across a broader range of wavelengths. Though less efficient than high-end silicon cells, quantum dot systems promise lower manufacturing costs and the ability to be sprayed onto surfaces.

3. Perovskite Spray-On Solar Cells

Able to exist in liquid form, perovskite materials allow for spray-on photovoltaic layers. Initially demonstrated by the University of Sheffield in 2014, perovskite solar paints offer a promising combination of high efficiency and ease of manufacture, potentially rivalling traditional panel efficiency.

Future Applications of Solar Paint

• Augmenting Existing Solar Systems: Solar paint could layer additional power-generating capability onto rooftops already fitted with solar panels.

• Solar-Powered Vehicles: With adaptation, cars and buses could harness solar energy directly from painted surfaces.

• Standalone Power Generation: As efficiency and durability improve, solar paint could power homes and businesses independently from conventional panels.

Why It Matters

• Harnessing Untapped Surfaces: Solar paint transforms walls, roofs, vehicles, or even fences into potential energy-harvesting surfaces—without walled-off solar installations.

• Efficiency & Cost Gains: Perovskite cell efficiency soared from below 4% in 2009 to over 25% by 2021. Quantum dot technologies also show promising efficiency trends.

• Lower Environmental Impact: Unlike energy-intensive silicon panel production, solar paint processes often involve lower temperatures, simpler materials, and quicker carbon payback.

Challenges Ahead

Despite the optimism, several hurdles remain:

• Durability & Weatherproofing: Long-term stability under UV exposure, moisture, and temperature swings still requires refinement.

• Scaling & Standards: Consistent manufacturing, quality control, and professional application methods are still emerging.

• Market Readiness: Although lab prototypes are promising, commercial adoption is still several years away.