Energy Matters Forums

[agrov8]

Hello world,
So I read everywhere that iron-free 4mm toughened glass is all the rage because it's more efficient/doesnt block as much uv, withstands hailstones at 84km/hr, etc etc.

My question is ... are there some numbers (actual maths/experimental measurement) to support this, and how much more efficient is it than ..
a. standard glass
b. polycobonate

Thanks in advance.
Andrew.

[davidg]

Hello world,
So I read everywhere that iron-free 4mm toughened glass is all the rage because it's more efficient/doesnt block as much uv, withstands hailstones at 84km/hr, etc etc.

The applicable glass is already on the solar panel, which BTW is normally 3.2mm thick, the testing for impact of the glass is done in a lab with a ball bearing.

[ElizabethH]

Isn't efficiency of a solar panel dependent on the purity of silicon they are made of? Instead of the glass? That's why monocrystalline are more efficient than polycrystalline of thin-film. Here's what I found about efficiency: https://greentumble.com/most-efficient-solar-panels-on-the-market/

[agrov8]

so I eventually found this ref: https://amosbbatto.wordpress.com/2017/0 ... ar-panels/

"Standard glass has a solar transmission rate of 83.7%, meaning that 16.3% of sunlight won’t reach the photovoltaic cells below the glass. In contrast, the patterned glass commonly used in solar panels prevents much of the reflection of light, so it has a solar transmission rate of 91.4%. The addition of an anti-reflective coating raises that rate to over 94% and can reach as high as 96.2% for the best glass such as ArtSolar. Using that kind of specialty glass, good commercial panels will get roughly 10% or more light than the DIY panel."

It's a long read, but full of good technical info. if iron free low reflective glass cuts about 8% less light than standard tempered glass, or considering I am using 18.5% efficiency cells, this would make them equivalent to about 17% efficency cells.

Given I obtained standard tempered glass second hand at $1/sheet (9x4 6"cells), vs $110 AUD for iron free ... I can live with that. I'll make 8% more panel area instead because it's cheaper to do so.

A.

[australsolarier]

the glass is the least of the worries of solar panel manufacturers. absolutely. besides, there is nothing you can do about it anyway. i mean, you won't be able to remove the glass and put your favourite in. so, don't worry about it.