Taking the plunge into solar ?

[Andybpowell]

As you say in series, panel shading can be a problem
The top left and bottom right panels on my array in winter end up in shade at the same time, so in order to negate the problem my panels are paired in series bottom right three with top left three and top right with bottom left, this ensures that one string of six is at full output instead of losing both to the shade.
Problem with wiring in parallel is that the current goes up compared to series so you need to use much thicker cable.
6 panels in series voltage 204V current 9A is fine on 4mm cable
6 panels in parallel voltage 34V current 54A so you would need at least 10mm cable.
Even 6 in series/parallel voltage 102V current 27A so you would need at least 6mm cable as although 27A is just within spec for 4mm cable the volt drop would waste a lot of the power.

Exactly you minimise cable costs by putting them in series but the trade off is in reduced efficiency caused by shading so you need to do the maths and see if the additional cable costs outway the issues caused by serial panels

 

[Pingu]

We had our solar installed last January we have only got 4.3kW of solar with a 5.8kWh battery. Our usage means that during the summer we were averaging about 12kWh from the grid every month as the battery is enough to tide us over from sunset to sunrise. We also managed an average export of about 375kWh a month on top of our use.
The thing that has made it all work for us is that we are on an agile tarriff which changes every half hour so as an example last night for one period we were paid 1.81p a unit to use electricity and the rate stayed below 10p all night, meaning even with no sun we could charge the battery almost for free. It doesn't happen every night but is fun when it does.
Estimated payback is 6.5 years.
Below is our import / export from the last 12 months

View attachment 244591

This is the sort of thing that I'm hopinh to achieve after we have the battery.

 

[Idleness]

This is the sort of thing that I'm hopinh to achieve after we have the battery.

We are lucky and have a south facing roof big enough for 12 panels which makes life easy. A chap up the road only has East West facing rooves and has installed 12 on each. I suspect his output is much the same as mine but whereas I have a midday peak his is morning and evening which is obviously good for the teatime cost hump.

 

[Pingu]

We are lucky and have a south facing roof big enough for 12 panels which makes life easy. A chap up the road only has East West facing rooves and has installed 12 on each. I suspect his output is much the same as mine but whereas I have a midday peak his is morning and evening which is obviously good for the teatime cost hump.

We've also got a south-facing roof. I was working on the cars this afternoon and the front of the house was in shade from the houses across the road, but the roof was in sunshine. The little pylon sign was on the smart meter, even though we had to have the lights on.

This is our first winter with solar, and I'm pleased to report that we were exporting when the house was dark. It looks like solar has generated 2kWs between from 0830 and 1430, this saved about 88p and we will get about 14p for the exported energy. Daily cost to run the house is about £3.30 without solar, and we knocked a third off that.

 

[ExMX5owner]

We are lucky and have a south facing roof big enough for 12 panels which makes life easy. A chap up the road only has East West facing rooves and has installed 12 on each. I suspect his output is much the same as mine but whereas I have a midday peak his is morning and evening which is obviously good for the teatime cost hump.

I hear what your saying with regard to orientation our house is oriented ne-sw but we live in the tropics @ 16S, so for one third of the year south facing is favourable. so we split 2/3 north 1/3 south. without actually working out the finer math. It seems reasoable to me at least..

 

[Idleness]

There is a very good, if a bit fiddly, website which will calculate your solar output for various configurations.

JRC Photovoltaic Geographical Information System (PVGIS) - European Commission

Photovoltaic Geographical Information System (PVGIS)

re.jrc.ec.europa.eu

Although Europe based it does I believe cover worldwide.

 

[ExMX5owner]

Finally progress, getting the roof cleaned and painted prior to installation. Since we live under the approach to Cairns airport I wanted to paint "temporarilly of course" (Welcome to Perth) on the roof. But my wife wouldn't let me do it...

 

[ExMX5owner]

It is done, everything takes a long time here in Australia..I mean look at the traditional owners, they were here for 50,000 years and never invented the wheel..but credit where it is due, they did invent a stick that when you threw it away, it came back. Europeans never achieved that.
But we tried to stress the system out, 6 air conditioners, 2 computers, a stereo with three amps, 2 fridges, a pool pump, all the lights on, the oven, all four elements on the stove. But it wasn't until I went to make a cup of tea, we stopped providing the grid. Lesson learnt, don't drink tea. Drink beer...