My experience - 2.6kW solar panels I can move home with

Obukit

@Martyn I have an electrician mate who will give it the once over but its IMO fairly simple.

With the voltages I am going on putting a multimeter over four panels in series which read 160V. They are JA solar 325W panels. So it would seem you would get away with two in series, although two sets of four perhaps gives you a bit of breathing room. I don't know much about ideal voltages.

In regards to matching I thought if you had two sets if four in parallel then you just add the watts from each circuit, even if they are different, with voltages of course staying the same. Again though this us a learning curve for me!

mmmmikey

Obukit wrote: »

In regards to matching I thought if you had two sets if four in parallel then you just add the watts from each circuit, even if they are different, with voltages of course staying the same. Again though this us a learning curve for me!

The issue here about matching is about inverter efficiency - that is, how good the inverter is at converting the varying DC power from your panels into AC mains power output. Although the inverter will still function if you connect different panel sizes, orientation and angles it won't be very efficient.



I won't pretend to understand the intricacies of MPPT inverters but the bottom line is that for the system to work efficiently you need to group panels of the same type, angle and orientation and either connect them to their own input on the inverter or use multiple inverters. In my case, for example, I have 4 panels on a south facing roof connected to one inverter and 12 panels on an east facing roof connected to another completely separate inverter.


Worth persevering with. If you have a hot water cylinder with an immersion heater, solar immersion controllers which use any spare solar power to heat your water are worth looking at. I have a Solic device but there are a few different makes.

Martyn1981

Obukit wrote: »

@Martyn I have an electrician mate who will give it the once over but its IMO fairly simple.

With the voltages I am going on putting a multimeter over four panels in series which read 160V. They are JA solar 325W panels. So it would seem you would get away with two in series, although two sets of four perhaps gives you a bit of breathing room. I don't know much about ideal voltages.

In regards to matching I thought if you had two sets if four in parallel then you just add the watts from each circuit, even if they are different, with voltages of course staying the same. Again though this us a learning curve for me!

Hiya, my dealings with the DNO had to be on a 'this is what we expect to say' basis, as they could only accept requests and notifications from appropriately qualified sparkies. I actually put the form work together for an application for 5.9kW export, and that required the sparks qualifications to be listed, and signed by them.

In fact, I had to do it twice, as the first installer fell through, and to my surprise the agreement was not with me, my property or my panels, but with the appropriately qualified installer, so had to start again with new installer (well not quite start again, as the DNO were extremely helpful).

Those panel voltages look fine, and tbh I wasn't thinking about how power ratings of panels have grown, my mistake, but just saying that you do need to take note of the minimum voltage requirement of the inverter, but also the MPPT's minimum which is typically a bit higher.

Regarding strings, if they don't match then you need separate inverters, or multiple MPPT's. For a single MPPT with multiple strings, those strings need to be identical to get the best out of the panels, so same number of panels, orientation and pitch.

agentk

agentk wrote: »

Once you have identified a place to mount the inverter you just need to connect the AC side though the isolation switch (supplied with kit) into the meter (supplied with kit) and then connect it to anything on your sockets ring main. Despite the size of the inverter, the maximum it will kick out on a <3kw kit is 13amps, so it's not an issue.quote


Oh dear & DC isolation.

Why not just fit a 3 pin plug with a rusty nail as a fuse!

sorry don't be offended by my post just thought i would prompt a discussion on this and the more knowlegable would chip in . great write up! Still a bit concerned about wind force on the panels though.Think of a kite surfer might truely br portable:beer:

Obukit

Definitely not offended - as I said it was a learning curve for me and I thought at least putting what I had gathered, right or wrong, might help somebody.

R.e. them taking off, between the eight panels there are ten dense blocks from Wickes- probably weighing 200kg plus between them.

I don't know if there is a formula as to how much ballast is needed - reading online the consensus seemed to be "too many variables" - but if they do blow away I will be surprised. Luckily we live in a fairly sheltered area so hopefully the ballast won't be tested!

Kernel_Sanders

Obukit wrote: »

The idea that anyone would want to use a normal plug is a bit scary .

Would it concern you to discover that somebody was using such a plug for a 3 kW immersion heater? I'm old enough to remember when these were commonplace, although the socket always seemed to have a neon light and may not have been 3 kilowatts.

Martyn1981

Kernel_Sanders wrote: »

Would it concern you to discover that somebody was using such a plug for a 3 kW immersion heater? I'm old enough to remember when these were commonplace, although the socket always seemed to have a neon light and may not have been 3 kilowatts.

Hiya, I assume you mean the immersion was plugged in. But just to be clear, that means the plug and its 'prongs', the male part of the connection were connected to the immersion, not the mains power.

In the case of 'plug n play' PV kits, these have the PV and inverter on the other end, so the power comes out of the male end, and that's where it starts to get scary. These are legal in most (I think) European countries, but not in the UK, and I assume that pulling the plug shuts down the inverter almost instantaneously, but it's not something I'd like to test.