Multi-colored solar buildings could be the future of green architecture

As solar panels become an increasingly popular source of energy and heat, they are no longer just for rooftops.

Especially in urban areas where space is limited, placing solar panels on facades or other more visible parts of buildings is a necessity.

But their standard monochromatic color scheme leaves designers with fewer options for making buildings attractive. Some architects have even described solar panels as ugly or an eyesore, saying that their appearance is an obstacle when integrating them into projects.

The problem often arises when trying to sell or rent a property where appearance really matters.

Now researchers at the American Chemical Society have created solar panels that can take on a whole range of colors while produce energy just as effective as the traditional ones.

Why are solar panels usually dark in color?

Elements appear a particular color because they reflect that wavelength of light instead of absorbing it. So if the solar panels are to absorb as much light as possible, they should be a deep black color.

Other attempts to make the panels more dynamic have resulted in less energy production, higher costs, or even unwanted iridescence.

So Chinese researchers – Tao Ma, Ruzhu Wang and their colleagues – looked for an inexpensive way to color solar panels without reducing the power they produce.

How did researchers make solar panels more dynamic?

The team sprayed the surface of the panels with a thin layer of something called photonic glass. It is made up of microscopic spheres of zinc sulphide which let most of the light through.

Some of the light, however, is reflected depending on the size of these spheres.

Using this, the researchers caused the solar panels to take on hues of blue, green and purple. And, despite the coating, their efficiency only dropped from 22.6% to 21.5%.

These photonic glass panels retained their color and also performed well in durability tests. The team behind the research says the technology can also be easily scaled up for manufacturing.

Now they are looking for a way to achieve a more vibrant and wider color gamut.

Marjorie N. McClure