How much am I getting ripped off for my solar panels?

[sailingharry]

Originally Posted by lawrence_craig

I have an MPPT controller. Measured peak voltage is about 15V, 10A.

That’s the thing, I’m getting nowhere close to 300W. I have never seen above 200W. But I have only had during winter in the Caribbean.

Angle of the sun has a big impact. You need to multiply the rate output by the cosine of the angle (direct overhead being 0 degrees). In June in the Caribbean, you pretty much get that. In December in the Caribbean, you are about 45 degrees (the sun is 23 south, and you are 20 north). Cos(45) is 0.71 -- in other words, your theoretical maximum output of a 300W panel on Dec 21 at latitude 22N is 212W, not allowing for the further loss due to the longer path through the atmosphere.

You can get back a lot of that with an adjustable mounting system, but that requires constant attention.