Why Are Solar Panels So Expensive?

How Mono Crystalline is Made

To better understand the expense of a single solar panel, it is necessary to know how the highly efficient mono crystalline cells are produced.
Silicon is a semi conductor that can either block or conduct electricity, depending on how it is treated.
It has taken decades to perfect the manufacture of mono crystalline crystals. The process starts out with heating raw poly crystalline in sealed ovens to over 2500 degrees Fahrenheit. It is then purged with argon gas to eliminate any air.
The resulting lake of molten silicon is then spun in a crucible and a silicon seed crystal, roughly the size and shape of a pencil, is then lowered into it while spinning in the opposite direction.
As the molten poly crystalline is allowed to cool, the seed crystal is slowly withdrawn at roughly 1.5 millimeters per minute. The result is a single crystalline weighing around 440 pounds and a diameter of approximately 200 millimeters. The silicon is so strong it can support its entire weight by a single thread just 3 millimeters in diameter. It is brittle but must now be cut down to size without shattering.
After testing with chemicals and x-rays to check its purity and molecular orientation, it is fed into a silicon Salomé slicer. A ten ton wire saw using a fast moving web of ultra thin wire is used to produce mono crystalline wafers. These wafers are very thin and 99.9 percent pure.
These almost pure wafers now go through a buffing and lapping process.
It is time consuming and expensive to manufacture these silicon wafers. Couple with the fact that less than half a dozen facilities even manufacture mono crystalline cells, it is easier to understand why a solar system can be so costly.
However, with paybacks on solar systems averaging between 4 and 7 years, the high cost of manufacturing silicon is less expensive than the cost of purchasing energy from our utility companies.