Planning 1st solar kit on the lodge from main house

[Comandos]

Good afternoon all,

Firstly big thank you to all contributing to this forum as well as youtube, you are incredible source of information to all of us who are new to solar world.

I live in UK and with the current jump in energy prices has made me think about solar panels and join the community of ever increasing solar owners. For the last 2 weeks I have been researching into solar (spent too much time into researching battery set ups but now decided that will skip the batteries for the time being), we live in the main house but have adjacent lodge cabin at the back of the garden which has large enough roof facing south and hence I have decided to install panels onto the roof of the lodge and if needed on our detached garage that also has south facing roof (pictures attached), this will make the installation much easier as we we will avoid the whole main roof on 3rd floor installation complexity and cost, but also the roof on main house is not that big so the lodge is better option all in all. However have the following questions:

1. Solar kit will be grid tied, the main electrical box is at the main house, but have small box in lodge and garage (picture attached for the one in lodge), I understand the inverter would have to be plugged into the main box in the house where the meter is, rather than the small box in the lodge or garage (my electrician will do all of this, but he has never done solar) so I thought I would just double check.

2. If so, my plan is to run cables from the solar panels on lodge roof to the garage (have decking everywhere so not an issue to hide them), install inverter in the garage and then connect it to the main house electrical box for grid tied system - are there any issues with that? Currently not planning to get any £ for exporting to grid as it would be DIY and not MCS certified to receive £, however the main aim of this is to be able to use generated energy in the main house, garage and lodge.

3. South facing lodge roof has size of 8m length and 2.8m width, so if I would be fitting 360w panels, I could fit 7 in portrait orientation and 4 in landscape - would all of them need to be connected in either string or parallel or mixed to improve efficiency?

4. Past 15:00/16:00h time, some shading comes onto the roof of the lodge from the trees, only around 1 or 2 metres in size, therefore couple of panels would get shade on them end of the day - what would be the best way to improve efficiency - the main part that does not have shade connect in string and shaded side in parallel? Or add micro inverters or panel optimisers to those affected panels?

5. As per attached pictures, if I understand correctly panel fittings such as Renusol with long bars are suited for vertically run beams? In our case, could I not use cheaper individual fittings as per the ebay link below?

Ebay fittings

Apologies for such a long topic and so many questions, I just want to make sure I get it all right and order the correct kit, thank you in advance!

 

[45North]

Edit: A lot of this is local, obviously, but fwiw I can give you my understanding - albeit from another country!

You may have done this already, I don't know.
If you're going grid tied your first step is to check with your power company:

• first you need them to confirm they are accepting new grid-tied customers (this is not a given as many places are already fully subscribed or have waiting lists)
• they will also advise how they do it and what equipment you need in terms of safety cutoff switches, two-way meter, etc.
• determine the terms of the agreement - how much they pay/credit for your power and does that make financial sense for your investment

 

[Comandos]

Hello 45North,

Thanks for your reply, with regards to connecting to grid, there is no issues at all as for any solar system up to 5kw. grid operator only needs to be informed before or after installation, mine would be just under 5kw.

With regards to payments, currently I would not be receiving them as system is DIY and to get payment you need to have it installed by authorised company that works under MCS scheme, but as the max you can get at the moment is £0.05 per kw, it is not big loss compared to double the cost of installation.

 

[Comandos]

Hello guys,

Would anyone be able to help with any of my questions above? Thank you in advance!

 

[MisterSandals]

3. South facing lodge roof has size of 8m length and 2.8m width, so if I would be fitting 360w panels, I could fit 7 in portrait orientation and 4 in landscape - would all of them need to be connected in either string or parallel or mixed to improve efficiency?

You connect in parallel or series to attain the voltage that works with your inverter/SCC.

4. Past 15:00/16:00h time, some shading comes onto the roof of the lodge from the trees, only around 1 or 2 metres in size, therefore couple of panels would get shade on them end of the day - what would be the best way to improve efficiency - the main part that does not have shade connect in string and shaded side in parallel? Or add micro inverters or panel optimisers to those affected panels?

Putting differently shaded portions of your array in parallel groups is best. Micro inverters or optimizers is another, different solution.

What is your inverter?

 

[Comandos]

Hi MisterSandals,

Regarding inverter, most likely I would be going with either Solis 3.6kw 5G dual MPPT or Growatt 3600TL Dual MPPT - to what I understand both good brands.
If I understand correctly, most of the inverters can connect 2 sets of solar panel arrays, so potentially 1 set of panels could be connected in series and another in parallel providing wats/amps match those of the inverter?


Thank you.

 

[TEV]

so potentially 1 set of panels could be connected in series and another in parallel providing wats/amps match those of the inverter?

It seems that you should read this first:

Solar panel strings: Parallel & Series explained

When solar panels are hooked up in series you connect the minus of one panel to the plus of the next panel. The voltages are summed, but the current remains the same: Putting panels in series is desirable as it keeps the amperage low, and amperage is the key factor in cost of the wire. Now...

diysolarforum.com

Figuring out how many panels in series and parallel based on your MPPT

Update: See Will's Video on the topic. MPPTs and String inverters can be quite perplexing at first as you try to figure out what the panel configuration should be. If you're not sure what's meant by serial and parallel in regards to solar panels check this link out first. Easiest of course...

diysolarforum.com

and more here : https://diysolarforum.com/threads/resources-for-beginners.16207/

 

[MisterSandals]

If I understand correctly, most of the inverters can connect 2 sets of solar panel arrays, so potentially 1 set of panels could be connected in series and another in parallel providing wats/amps match those of the inverter?

I would think if you have a dual MPPT SCC, you would connect an array to each rather than paralleling them (combining them in parallel that is). So with 11 panels, one array of 5 panels in series (combined Voc needs to be lower than SCC max input voltage) and another array 6 in series if voltage works, or 3S2P (3 in series, those series string then both in parallel to one MPPT).

If you can work out panel Voc and SCC max input voltage, it can be properly calculated.

 

[Comandos]

Thank you both for the answers.

It looks like I have done a newbie error and asked multiple questions before going through all of the sticky information provided in this forum. I will go through all of that first and will text back if there is still something unclear, thank you.

 

[12VoltInstalls]

first you need them to confirm they are accepting new grid-tied customers

Currently not planning to get any £ for exporting to grid as it would be DIY and not MCS certified to receive £, however the main aim of this is to be able to use generated energy in the main house, garage and lodge.

Double check with electrician to assure that local codes don’t require charging equipment to be adjacent and accessible to main entrance / distribution panel. That’s a good thing to know.

looks like I have done a newbie error

Ish. You have some plans. You fielded them and got relevant self-ed materials to read.
If you hadn’t asked specific questions regardless of prematurity it would be s “newbie error” by expecting people to spoon-feed you solar pablum. That would annoy people.

Instead you had a direction and asked for guidance. Welcome to the forum.

researching battery set ups but now decided that will skip the batteries for the time being

I would at least plan for enough batteries for 12-24hrs. Three days is generally recommended but with all the potential in your system you should take full advantage of it. You can then use some ‘sunlight’ power after dark rather than grid, and have a modicum of coverage for power outages.

The fly in the ointment is that batteries are most often way more expensive than grid power or generators.