% loss of solar cable acceptable?

[macd]

So double the voltage, half the amps and you get the same power with thinner wire.

It's basically magic is what your saying.

Sorry, northcave. You may recall similar references to series/parallel wiring in your previous threads about solar v wind and 'marine' panels. I'd assumed you were familiar with this 'magic'.

 

[VicS]

So double the voltage, half the amps and you get the same power with thinner wire.

It's basically magic is what your saying.

Well not magic. Just a bit of elementary science and some magic maths

Put them in parallel you get twice the current that you get from one, but at the same voltage. So you need wire twice the size of what you need for one.

Put them in series you get double the volts but at the same current.

But I hear you say same current therefore that means wire the same size as I needed for one.

Now here's the magic bit:

Because the volts are doubled the actual volts drop you can allow is doubled ( 3% of 12 V = 0.36 V. 3% of 24 V = 0.72 V)

Because the actual volts drop you can accept is doubled you could halve the size of the cable

So if you need 2.5mm² for one panel you'd need 5mm² for two of them in parallel but you would need only 1.25mm² for them in series