Which direction should I add more panels?

[CZAUTO]

Not realy sure where to post this but here goes.

I’ve got 12 x 330W Canadian solar panels (about 6 years old) in 4 strings of three, running through a Smartsolar 150/70TR MPPT to charge my 3 x eTowers. I recently acquired another 6 x 600W JA Solar panels but I’m still in 2 minds where to install them. I haven’t bought the mppt’s yet and need to make up my mind before doing so.

The current setup is in green, all pointing North at roughly 38deg. My question is now this. Do I install 3 panel East and 3 West in the red squares or all 6 in the Orange square, also due North. If East and West each string will get a Smartsolar 150/45 mppt and if North, another 150/70TR. My Inverter room is almost directly underneath the current array with at most 8m of cabling to the MPPT. I do have more than enough space on my workshop roof (marked in blue) for the whole array but have this 100+ year old pepper tree that’s going to give me shading issues and I simply will not cut it down, oh yeah and I’ll have the issue of about 40m of cabling distance so would probably then have to swap the 150/70 for something in the line of a 450/200 which is k@k expensive. If going the E/W route I will get sun very early and very late, seeing that I’ve got very little shading issues. If going the N route, I’ll have to install it on a carport roof which is quite low and then I will have shading issues, esspecially in winter, caused by the neighbour’s house. I know some of you guy’s have played with E/W arrays with proper results. What do you suggest?

[Swartkat]

My only opinion here is, AVOID shading at all costs! When I relocated all my panels a few months ago, it was like a completely new installed system.

In winter, I had to get everything done before 14h00, thereafter my panels were pretty much non existent.

In summer, proper production only started at around 09h30. With the shade removed, I had almost full production capacity at around the same time and could pull my geyser from 07h00.

A West and East array makes no sense for me now as I have no shading. I have 100% SOC still at 17h00 currently and winter pretty much started - summer solstice being 21 June.

[plonkster]

@Swartkat

I have 100% SOC still at 17h00

Invest in an EV. It will fix that little problem…

[Swartkat]

I have been reading up on yours as well as a member on the SA 4x4 forum with regards to your BMW I3 journey.

I am definitely considering an EV (read I really really want one!).

But this will only happen in about 5 years time. Who knows what will be available at that time at hopefully better prices.

[plonkster]

Prices are coming down rapidly. Good for buyers. Less good for people who bought and kinda want to keep the resale up.

Volvo XC40 now around 700k.

EX30 touching 650k now. That’s Hilux money.

Ora 03 pretty consistently around half a bar.

Brand new BYD Dolphin around 540k, which means when they hit the second hand market a year or so from now, it will be under half a bar.

Mini Cooper SE around 400k now.

BMW i3 as low as 250k… but then it is getting quite old. You really want 2017 or later with the split EME/KLE setup.

[CZAUTO]

This what my Pv yield, usage, etc looks like on a good winters day in the Karoo. This was yesterday. My geyser switches on at 11am though and I use my workshop equipment a lot through the day (200ltr compressor which runs a lot seeing that I use it on my cnc laser, 3 x 3d printers basically runs 24/7, Welding, 2 x car lifts used quite often, etc) so my usage are a bit rough. We are a family of four and the kids simply cannot get it in their minds to switch of lights and other equipment. I think I will be okay with the extra 3600Wp PV which would bring me to a total of 7560Wp. I plan on doubling my storage within the next 2 years though so that might become a problem again in future. I’ll see how it goes though. First want to get the new 600w’s on the roof and connected, preferrably before winter ends

[Bobster]

For me the benefit of extra panels is during poor weather. I recently did an upgrade and I now have power to throw away on sunny days. On overcast days I get better production and have less need to resort to the grid.

My panels are split, really N-ish and E-ish. The effect of this is that in the morning we get lets of power early on. The interesting thing is that the E-ish string can provide useful PV into the afternoon, about 14:30 at the moment.

We have settled into a routine whereby we use lots of electricity from about 8:30 to 13:00, and then not so much. Very little at night.

So think about your routine and when the extra juice would come in handy, or how you would like to be able to change your patterns.

Also how much battery do you have? I could probably get through to about 10:00 with our current battery and useage. If you have, say, 20kWh then maybe it’s better to point everything N, rely on the battery a bit longer into the morning and then get a big recharge in the middle of the day.

My hand is forced to a degree because most of my roof space faces E or W, there is only a small amount (6 panels max) facing N.

[Swartkat]

@Bobster

We have settled into a routine whereby we use lots of electricity from about 8:30 to 13:00, and then not so much.

Shading? Or other reasons.

[Bobster]

@Swartkat

Shading? Or other reasons

We’ve always had the N/E split on panels, so early on we settled into a “use it when you have it” routine.

[CZAUTO]

All righty then. So my 4th eTower was added (luckily I built the stand to be able to take 4 when I built it) and I installed the East and West facing arrays on Saturday. Today was the first day, luckily a beautiful, sunny day, to see how PV production has increased.

Yesterday I was busy neatening all the wires (except for the solar wires coming through the roof after I ran out of trunking) so production couldn’t be tested properly.

Seeing that the new arrays are laying flat facing East/West at about a 32deg angle, production is not great but I guess sommertime things will change dramatically with the sun being higher in the sky.

Ignore the PVC conduit. I ran out of Bosal galvanized conduit and could not find any stock in town so had to order. I place the PVC conduit where it would be easiest to replace when the galvanized conduit finally arrives. For now there’s about 6m of PVC and the rest is Galvanized metal.

For now, this is what the setup looks like. Some small pieces of trunking to be installed and then new grounding wires. I hammered in 2 new 1m earth spikes while I was busy. One for the inside DB and one for the PV system. I still need to get it checked for a COC so I’m sure there will be something I missed. I just want to let it run for a few days to check for any issues before I do the finishing touches. Oh and I’m busy 3d printing a ducting system for the blower fan which is going to run underneaath the inverters, blowing air upwards through the inverters and MPPT’s. The inline blower fan is electronically controlled and set to start pushing air in from 25deg Celsius upwards, increasing speed as temperature rises. There’s also an Whirly bird thingy on the roof in which I installed a 10" automotive radiator fan which is connected to it’s own 50W solar panel. The roof extractor fan only runs when the sun is shining and works perfectly, even in 45deg Karoo summer days. I actually installed it way back when the room was still used for my 8Kw diesel generator and it kept that cool so I thing it’s going to be fine. The inline fan is also conencted through the Tuya app so I can check the room temps from anywhere, increasing the fan speed should it need be. It never reached more than 36deg throughout the summer though.

There’s still a lot of tidying up to do, shortening and crimping CANbus wires, etc.

I don’t think it looks too bad keeping in mind that I’m a qualified mechanic, not electrician

This was today’s production per MPPT.

This was total yield 7 days ago, 17.2Kwh production on a perfect winters day in the Karoo,

and this was total PV yield today, 29.2Kwh total production. An increase of 12Kwh. I’m happy with that. My grid breaker has been switched off since yesterday so I haven’t used anything from the grid an my batteries were fully charged and my 150ltr geyser at 65deg at around 3pm. I had to switch on the mains and enable grid feedback just to see what maximum PV production is possible. I’ve fed 4.8Kwh into the grid (which I obviously paid for since I don’t have a bi-directional meter) but it was just a test. I’ve since switched off the mains again and will see what the batteries do overnight. This morning at sunrise they were at 57% SOC.

I’m more than chuffed. If and should I find more batteries I’ve got more than enough roofspace to ad 6 more North facing panels but I really don’t need it. But hey! solar is worse than racecars. You always want more. Only difference is you get a return of investment with solar…not so much with racecars

So let’s hear the critisicm. I can only improve. At least it’s working as planned.

[Richard_Mackay]

Victron Multiplus running in single phase parrallel

Great to see your different panels incorporated.
How many MPPTs can be added to this inverter?

[CZAUTO]

As far as I know, 10 Max. Well that is the max number that the ve.direct can handle apparently.

[plonkster]

@CZAUTO

As far as I know, 10 Max

Oh we have sites with a LOT more, but granted, those are VE.Can. We have sites running 64 MPPTs together with 6 PV inverters and the full 12 x 15kVA Quattro setup on the other side.

[CZAUTO]

Yes, With VE.Can there’s no limit but with VE.Direct on the smaller MPPT’s you’re limited to how many VE.Direct /USB ports your GX device have. It’s possible to add USB to VE.Direct with a powered USB hub but as the manual states you’re still limited to 10 devices. I don’t think I’ll ever get there