Lightweight, Glassless Solar Panels

Thinner glass, misconception: Less weight, same properties.

  • The trend toward thinner glass in PV modules has raised questions about heat treatment. PV module data sheets are not usually specific about the heat treatment of glass. They almost never cite a standard.

  • If low-energy cracks happen in the field, accelerated tests that cause high-energy cracks probably aren't driving the same chain of mechanisms. Even though we’ve found that 2-mm glass in PV modules is usually fully tempered per ASTM C1048, it tends to have a lower surface compression than the 3.2-mm glass used in PV modules.

 The frame protects the glass, misconception: Flaws at Edges and Surfaces

  • The strength of a brittle object like a piece of glass is set by preexisting flaws, usually microscopic ones. Even if glass is properly supported and properly strengthened, it will be easy to break if it has a flaw on a surface or edge.

  • With pressure to reduce cost, the processes for finishing the glass edges and assembling the modules may be done less carefully. Processes that are harsher on glass edges create more and bigger flaws. Glass with bigger flaws, especially at surfaces and edges, can break more easily and into a lower-energy pattern.

 Glass-glass misconception Edge Pinch

  • The margin of a crystalline silicon PV module has no solar cells or ribbons, and encapsulant can flow a little bit during lamination. In a single-glass module, the flexible backsheet bends and the margin comes out thinner. In a double-glass module, the glass can pinch together at the edges during lamination. Edge pinch bends the glass, sometimes putting it at the brink of failure as soon as the module is made.

 Bigger is better, misconception: Module Size, Glass Thickness, and Mounting

  • PV modules have gotten bigger, growing from what we call size L (around 2 m2) to size XXL (around 3 m2) in just a few years.

  • When loaded by wind or snow, a bigger module has more total load on it. When the glass is only supported near its edges, these edges bear more load in bigger modules. When the frame is only supported at four mounting points, these mounting points bear more load in bigger modules. Module mounting points have often stayed the same or moved closer together, even as module size increases. Cost pressure can force mounting structures to be smaller, less rigid, or both. Even a rigid module may be more likely to fail if it is mounted on a floppy structure.

 Frame is sturdy, misconception: Frame Interactions

  • Forcing glass into contact with something solid can create a new flaw that weakens the piece of glass, local stress that makes a flaw more likely to turn into a crack, or both. Wind and thermal expansion can force PV module glass into contact with a metal frame. Sand trapped in the frame could make frame contact more damaging to glass. Larger modules worsen both of these problems.

 Reviewing the Factors

1. Reduced glass strengthening
2. Flaws at edges and surfaces
3. Edge pinch
4. Larger module area and thinner glass without reevaluating frame and mounting points
5. Contact between glass and frame, with or without sand.

 Conclusion:

All these factors are completely excluded In the Quadra product architecture. By using a high-tech polymer replacement for the glass and PEC (Planar Electrical Contacting Technology) we do not only reduce weight, minimize installation complexities and are opening up new areas of application (even in situations and applications where PV was not even considerable before): we rule out all described problem-factors as described in this NREL report.  

  • "Our team recently achieved something remarkable: conducting not one, not two, but THREE interviews all powered by our new 5kW Mobile Solar Generator (Power Wagon) from MES. With the solar panels, none of these extensive interviews even made a dent in the reserve battery power!"

    Operator, North Star Film Productions