The points that make SunPower different are: the energy you can get from the same foot print. We have a three high efficiency residential panels – E20-327 watt at 20.4% efficiency (black frame), X21-345 watt at 21.5% efficiency (black frame) and the NEW X22-260 watt at 22.2% efficiency. The we have commercial E series – E20-327 & E20-435 watt, 20.3% efficiency commercial panels (with silver frame). All data sheets attached.
SunPower is back contact – no grid or ribbons on the front of the cell – everything is moved to the back – less chance of things going wrong – cells cracking, ribbons breaking and we have virtually eliminated corrosion. The back of cell is fully covered with copper, making the cell strong and robust and the cell interconnect bar is made to expand and contract with the cells. When you see the cell break demo the value of the copper becomes apparent.
SunPower has a 25 year product (no one has anything close!) and a 25 year performance warranty. We warrant stuff other companies baulk at. We cover shipping, install, commissioning and removal of the old panel. I have attached the warranty brochure for you.