Compare solar panel efficiency, specifications, reputation and price
The 5 most efficient solar panels currently used in residential installations in America
| Manufacturer | Model | Maximum Efficiency |
|---|---|---|
| Sunpower X Series | SPR-X21-345 | 21.5% |
| Sunpower E Series | SPR E20-327 | 20.4% |
| Panasonic HIT panels | N330 HIT | 19.7% |
| LG Solar | LG375N2W-G4 | 19.1% |
| Canadian Solar | CS 6K-300MS | 18.33% |
| Solar World | CS 6K-300MS | 17.89% |
What does solar panel efficiency mean?
Solar panel efficiency refers to the percentage of the solar irradiation that falls onto a solar panel or cell that the panel or cell can convert to usable electricity or electrical energy.
Currently scientists think that the maximum theoretical limit for solar cell efficiency using currently known materials is around 27-28%.
How much weight should I put on the efficiency of a solar panel when choosing a system for your home?
The key thing to understand about solar panel efficiency is that differences in efficiency are already taken into account when a solar panel is rated at a particular wattage.
So all other things being equal a 300 watt solar panel with an efficiency of 18% should produce the same amount of power as a 300 watt solar panel with 21%. The more efficient panel may be slightly smaller but the power output should be the same.
What is the most efficient solar panel available?
The most efficient solar panels currently available for use in residential solar installations are the Sunpower solar panels that have an average module efficiency of around 21%.
How much more should I pay for a more efficient solar panel?
As stated above and elsewhere on this site we don’t think it is worth paying too much more for the very highest efficiency panels on a per watt basis because efficiency has already been calculated in when rating a solar panel as being able to produce a specific wattage of power.
I have seen some really misleading advertising materials from makers of the higher efficiency solar panels that are trying to convince people that these solar panels produce vastly more power than solar panels of lesser efficiency.
However, for a panels like Sunpower and Panasonic where there is both high efficiency, a low temperature coefficient and a very strong warranty I would be prepared to pay around 10-15% more for their systems. However, this is more for the excellent performance in high temperatures rather than the efficiency.
If efficiency doesn't matter that much what factors should I consider when buying solar panels?
Other factors are far more important when deciding what brand of solar panels you should buy for your home or business such as:
- Do I trust the manufacturing quality of the solar panel manufacturer;
- Do I think the company is financially stable and likely to be around should I need to claim on my warranty
- Other specifications of the solar panel such as temperature coefficient and power tolerance;
- The terms of the warranty offered on the panels
- Do you like the look of the panels (you are going to be looking at them for a long time)
When does the efficiency of the module matter most?
The efficiency of the module matters most when you only have a small roof space to work with and you are trying to get the most power you can from that set space.
The thing that a high efficiency solar panel does is make more power from a defined space.
However, for a panels like Sunpower and Panasonic where there is both high efficiency, a low temperature coefficient and a very strong warranty I would be prepared to pay around 10-15% more for their systems. However, this is more for the excellent performance in high temperatures rather than the efficiency.