Long envisioned as a way to cut the cost of solar cells, researchers have looked for materials that could be sprayed onto a surface to produce electricity. The general idea is to have a material that, once applied to a surface, would dry to form interconnected, microscopic solar cells.

Nanotechnology is at the core of today’s efforts to develop what many refer to as solar paint. Some recent developments have advanced the technology and provide a glimpse into the potential benefits solar paint might one day deliver.

Solar cells based on solar paint will likely offer a trade-off in performance versus cost. Solar paint-based cells are expected to have fairly low solar conversion efficiency rates. Perhaps in the single digit range at best. Currently, the highest touted efficiency rates for small experimental samples are in the six percent range. That is significantly lower than today’s best photovoltaic cells, which deliver in the low to mid-20 percent efficiency.

However, the thinking is that a solar paint based approach will offer cost savings in several areas, thus making them more attractive. Many of the solar paint technologies being developed today would offer lower manufacturing costs. The materials could (theoretically) be applied under more common conditions such as at room temperature in an ordinary facility. This would yield be a much lower cost than using clean rooms and silicon fabrication facilities, as is needed to produce the current generation of photovoltaic solar cells.

Unfortunately, solar paint also has several potential obstacles to success.

Nanotechnology-based approaches have been under development for nearly a decade with little movement from the lab to production environments. Questions remain as to whether the techniques used to make small samples in the lab can be industrialized to support commercial development.

Nanotech-based solar paints might also be rejected for use based on potential health risks of nanoparticles. This is a highly contentious issue. And opponents to nanoparticle materials might raise the cost of a solar paint project through legal actions.