Choosing flexible solar panels
Top surface
Flexible solar panels have the following materials for their top surface
- PET
- ETFE
ETFE flexible solar panels are less subject to delamination since have greater protection from the sun wheras PET solar panels are suitable for solar suitcases and folding solar panels where there is occassional use.
Back surface
There are three main options for flexible solar panels:
- Fibreglass
- Aluminium
- Composites such as TPT, PET, TPE
Each surface gives the panel a different level of flexibility depending on the thickness of each material used.
ETFE benefits
- Higher output – higher percentage of sunlight passing through.
- Research shows ETFE degrades less in sunlight than PET – reduces sunlight damage and panel de-lamination.
- Self-cleaning – property of ETFE.
Flexible solar panels cell types
There are three main choices of material for flexible solar panels:
- Monocrystalline
- Polycrystalline
- CIGS (thin film)
Monocrystalline/polycrystalline vs CIGS
Monocrystalline and polycrystalline are typically around 16% efficient while CIGS are around 13% which means you get about 23% more energy from moncrystalline and polycrystalline. This is extremely important where there is limited space to mount the solar panels such as on a boat, caravan or campervan.
PERC cells
PERC solar cells are monocrystalline or polycrystalline with an extra reflective layer at the back of the panel, which can make them more efficient.
Flexible solar panels cell joining methods
There are two main choices:
- Front busbars (standard)
- Back contact (more expensive panels)
Back contact panels run the silver solder along the back of the solar cells making them more aesthetic and typically have a higher output.
Cheaper solar panels have 3 bus bars running across the front of the solar panel while more expensive panels have up to 9 bus bars, which may make them more reliable and increases output.
Cheaper solar panels have 3 bus bars running across the front of the solar panel while more expensive panels have up to 9 bus bars, which may make them more reliable and increases output.
Shingled solar cells
These are the latest technology are often the most expensive panels. Due to their shade tolerance they are ideal for campervans, caravans, boats and yachts.Standard panels have gaps between the cells with solder running across them.Shingled solar panels are typically PERC monocrystalline panels cut into thin strips and arranged overlapping like a tiled roof.
Benefits
- Greater output – shingled solar cells do not require lead solder busbars running across the surface of the panel, blocking the sun.
- Increased shade tolerance – conventional solar panels are wired in series so if a part of the solar panel is shaded it can have a significant effect on the level of power output. By contrast shingled cells are wired in groups in parallel minimising the impact of shade.
- More robust – tests show that the shingled approach is more resistant to damage.
- Sleek aesthetics – There be no gaps between the cells and no silver solder.
A note on half cut solar cells
These are standard solar cells cut in half. The benefit is that each half of the panel is wired separately, so less impacted by shade. They don’t offer as good shade tolerance as shingled solar panels.