A combination of several key technological advancements enables SunPower panels to operate more efficiently at higher temperatures, at lower light intensity, and across a wide range of weather conditions.
In most solar cells, numerous metal electrical contacts are placed on the front side in a fingered pattern. These “gridlines” are required to complete the electrical circuit and collect the solar electricity. But, wherever there is metal on the front of the solar cell, sunlight is blocked from entering the cell thereby creating shading loss. SunPower places all electrical contacts on the back of the solar cell, which eliminates shading loss from the front-side gridlines.
By locating the electrical contacts on the back surface, eliminating the problem of shading, the metal contacts can be made extra wide and thick to conduct electricity more easily. SunPower panels achieve conversion efficiencies of 22%, up to 50% higher than conventional solar cells.
Deliver most energy per square foot
SunPower high efficiency panels create a larger capacity system in a smaller space and have more room to optimize the orientation of the array. That means more solar kWh will be generated both annually and over the lifetime of the system.
An anti-reflective coating on the front of the cells captures sunlight in the cell and a silicon dioxide layer on the front and back sides minimizes the loss of electrons through the process of “recombination”. On the backside, this coating combined with the metal backing creates a mirror which reflects unused sunlight back into the cell. These technologies work to produce more current within the same space in SunPower panels compared to conventional panels.
No “light-induced degradation”
- Most conventional solar cells are made from silicon wafers doped with boron atoms (p-type). When first exposed to sunlight, boron rapidly reacts with trace amounts of oxygen in the silicon to form a defect that degrades the performance of the solar cell. SunPower panels are made with boron-free n-type wafers making them completely immune to this initial light induced degradation.
Visit the SunPower website.