JavaScript is required to run this application. Please enable JavaScript, then refresh this page.

What is the difference between the E and X panels?

Share Link:
Categories:

Summary:

The E20s are 20% efficiency, have a white backer sheet, and are the "workhorse" panels. The X21 - 335 watt panels are the latest ...

Answer:

The E20s are 20% efficiency, have a white backer sheet, and are the "workhorse" panels. The X21 - 335 watt panels are the latest model introduced, have a 21% efficiency rating. However, in all honesty, it is so difficult to get that kind of flash test rating, the silicon has to be so pure, that Sunpower has not been able to get a consistent batch of extremely high quality silicon to produce a consistent supply of X21s. In a sense, they put the panel together, and run it under a light that flashes for a fraction of a second, the panel puts out a wattage reading based on that short exposure to light. If it is perfect, it should "flash test" as a X21 with 21% efficiency. Most are flashing at just under the 21%, so they have to call them E20 - 327 watt panels.

Notes:

This question and answer is directly associated to a specific review. To view the review select the related link below.
Was this answer useful to you?