Imagine your buildings’ roof, canopy, skylights, and windows are generating energy for your power needs. It can be done by replacing your windows and sunroofs with photovoltaic glass.
It comes in various colours and varying degrees of transparencies from opaque to clear. With the climate crisis that we are in, it is an attractive source of renewable and clean energy, reduces the building’s carbon footprint, and a buffer against rising energy prices.
Photovoltaic glass is composed of solar cells embedded between two glass panes. These PV glasses or solar glasses can now replace traditional construction materials such as glazing or cladding while also generating energy (Solar PV Knowledge, 2019).
In developed countries, commercial and residential buildings account for 20-40% of the total energy consumed (Ghosh, A., Sundaram, S., Mallick, T., 2019). And the majority of energy consumptions is from indoor heating, cooling, and lighting. Replacement of glass windows and roofs with solar glass, especially in multi-storey buildings have the potential to generate enormous amounts of clean energy while providing power for the building.
These PV glasses can also be customised. Aside from generating power, it has add-on benefits like thermal insulation, provides varying degrees of transparency from zero to fully opaque up to 50% transparent, with a choice of colours for aesthetic purposes. Recently researchers have developed transparent solar cells, a breakthrough in PV glass engineering. (Scully, 2019).
How is this transparency possible?
MIT researchers have been making these transparent solar cells. According to the MIT article, these solar cells “absorbs only infrared and ultraviolet light, and this visible light passes through the cells unimpeded, so our eyes don’t know they are there”. Researchers at MIT have “deposited coating of their solar cells on various materials and used them to run electronic displays using ambient light.” So that when “coating” these solar cells on windows of skyscrapers would not alter its looks but more importantly provide more than a quarter of the buildings energy needs without altering its looks (Transparent solar cells, 2013).
In South Korea’s Ulsan National Institute of Science and Technology, they have also found a way to make these solar cells transparent by punching tiny holes into a 1-centimetre square cell of crystalline silicone – a material commonly used to make solar cells. These holes are so tiny, it is the size of a human hair. The holes allowed the light through them and create a transparency effect (Scully, 2019).
The power generated from solar PVs can be up to 70-80%. A standard domestic usage can reduce 2 to 3 tonnes off its carbon footprint, and a 50kWp non-residential building can cut 25 tonnes of its carbon footprint (Why Choose Solar, 2019).
As time goes by solar cells are only getting better and more efficient for both domestic and commercial use.
The creation of transparent solar cells is indeed a game-changer as it provides more climate adaptation options and flexibility for users while generating clean and renewable energy and reducing our carbon footprint.