Using optimizers

[Abeer]

Why do performance ratio and production decrease in PVsyst when using optimizers?

[Robin Vincent]

Optimizers won't necessarily increase the system production. Optimizers are especially useful when a part of the string is partially shaded, and has a different Impp (current at max power point) from the rest. Without optimizers, the whole string have to use the current of the worst module, leading to a lower overall production.

With optimizers, the shaded and unshaded modules can operate at their own optimum current, the optimizers ensuring the output current to be the same.

But when you don't have partial shadings, optimizers cannot improve anything. And since optimizers have their own efficiency, they end up increasing the system losses, leading to a lower PR.