The answer is: pretty wired!
Now, not every person interested in learning about solar is this interested. I get it.
But some inquiring minds need to know. We see all those panels on the roof, over a hundred in some cases, with one, two or three invertors. So how do those all connect? The answer for some will be – who cares!
Well, all we really need to care about is that the direct current (DC) electricity generated by the solar panels is converted as efficiently as possible to household alternating current (AC) electricity for grid-tied properties.
Now, if you are content knowing that your installer will ensure this happens – please feel free to get on with your day or evening. If, as a techno-nerd, you need to know – read on. Knowledge is not a bad thing!
A typical panel produces electricity at a maximum of 37 volts DC. A typical inverter is most efficient receiving 400 volts DC. This means that 11 solar panels wired in series (+ to -, – to + like the AAA batteries in your TV remote) would supply the invertor with up to 407 volts.
If these panels were rated at 380 watts, this group of 11 panels could produce 4180 watts.
But I have more than 11 panels on my roof – what now?
Well, a large capacity inverter has a rated input of 17 kW DC. So, four groups of 11 panels each could be wired in parallel (+ to +, – to – like if you need to jump your car battery) into a large capacity inverter, creating a 16.7 kW system.
Have more panels than that? Then simply install a second, even a third, invertor and wire the balance of the panels into those.
In a future blog, I’ll discuss how this wiring might look when battery backup is installed. Batteries are able to be charged directly from the DC electricity generated from the solar panels. No need for the invertor to convert to AC first, hence the wiring can be different.
In another blog, the differences between line invertors, microinverters and power optimizers, and how each works, will be discussed. Each of these may require different groupings and wiring.
Phew, now we can all be relieved to know that there is some rhyme and reason to all this wiring. And the result will all be the same, with clean dependable power available for your property.