SilverNodashi

Why do you guys draw so much on a single plug? If the 16A is not enough, then hopefully your house wires can carry enough to go higher.

You got the wrong side of the story, mate I never said it doesn't work. But I said that 42% is too optimistic in my opinion. 20-30% is what most other researchers got from trackers. At 20 or even 30% increase it just doesn't make financial sense to me. On a 1KW (4x 250W panels) Array you would need to add at least 2 more panels, which is then 50% increase @ R5000. Would a small solar tracker cost less than say R2500 (let's work with 25% increase due to the solar tracker efficiency) to build & install for a 1Kw array? On a 10,500w array (10Kw Infisolar grid tied inverter) will then require 8 more 250W panels at R20,000 to increase by 20%. Their manual doesn't show a configuration for 12,500w, but rather 13,500w so let's add 12 more panels, cost R30,000 and gives 28% increase. What would a tracker system of that scale cost? On 100Kw and 1Mw the economies of scale would work out about the same, or perhaps go down a bit. Fair enough, on larger installations, if you don't have enough roof / ground space, a tracker makes sens - not necessarily financially, but due to limits beyond your control. The point I am trying to make, is it really worth the money? My neighbor also built his own and it wasn't worth the money he spend building it. He's an engineer and designed & bult it himself, so it cost him a fraction of what it would cost of the shelf. Two years later he "parked" it and added 6 more panels on his roof. He said the total output was better than with the tracker and he didn't have to worry about panels flying off in high winds, which we tend to get a lot of.

Based on what? It would be nice if they published actual figures and test results. It would also be nice if they could compare that system to a stationary setup with the same panels, on the same roof, going into similar MPPT trackers, but his roof is too small and the outlay is probably too much. There's 10x Polycrystal and 8x Monocrystal panels on that rack So, let's assume the following: 1. The poly's are 72cells, so let's asume it's 300W (Yingli?) panels, or 3000w in total. 2. The mono's are also 72cells, but I can't find those panels on the web, so let's assume it's 250w, total of 2000W. 3. The normal calculation for good sun hours is 6 hours, so 5000W at 6 hours should produce round about 30Kw. 4. South Africa has on average 9 hours sunlight per day. 5. Lastly, lets assume the ventilation is good enough (should be in this case) that the panels perform 100% So, if they were stationary, we should have gotten 30Kw for the day. But since they're moving and getting 3 hours extra sunlight, they should produce 45Kw. That's 33% increase, and maybe it's even possible. It just sounds too optimistic to me. You will probably find that the sun is high enough between 8am and 16:00 to hit all the panels on that tracker, otherwise the panels at the back would be shaded by the front panels. So, who wants to build a tracker (let's forget about SABS and TUV approval which will increase the production cost significantly) and compare it with a stationary setup? 2Kw PV array per setup, going into similar MPPT trackers and central battery bank + central inverter so there's constant draw / usage on the system.

43% sounds a bit too optimistic to me!

And icecream!

I know, I just don't like talking rubbish, but a good joke is fun

hmmm, seems I need another 1000 posts! It's quite difficult to post 1000 useful posts though....

I want some units too ... ?

We replaced a +- 7year old "something else" for a 370L Bosh A++ fridge/freezer combo, about two years and it uses about 1W/h! The 210L Defy is probably about 25years old, with a leak at the back so it defrosts too quickly when run on the timer. Perhaps I should just empty + clean it, and seal it up.

300W aint much. My neighbor uses about 2Kw/hr at night. And that's with LED lights, efficient fridges, etc, etc. Alarms, electric fencing, etc all add up. Our house runs between 120KW and 3Kw/hour at night, depending on when the freezer pump kicks in. I should actually fix the leak at the back at some stage, perhaps it will use less power. All our lights are LED and we leave the TV, microwave, router, etc all on standby purely cause it doesn't make that big a difference. But ultimately if one could get past these problems it would help. At some stage I had a timer on the fridge that switched off at 5PM and on again at 7am, but the food defrosted too much during that period so now I'd rather pay for the batteries than the food.

What I tried to say is that we (DIY people) need to be careful of the advice given, as it could steer an uneducated person in the wrong direction. Misinterpreted information is often worse than no information at all.

Sure, and you can easily achieve this as long as you work within the limits of your system. In your case the Axperts, setup the way they are, give you limited energy per phase. As suggested already, you either need to connect them in parallel, or use a 3phase inverter which can utilize all the PV energy at once

@SBBS, I suggest you either get more solar panels and max out your PV capacity, or if you really don't want / need that many solar panels, get a hybrid 3 phase like the Infinisolar instead. It will work the way you want it to and probably save you some headaches in the future

You are wrong (pun intended ;)) if the batteries are all connected to a busbar, to the three inverters - then the batteries will still be charged from all three sources. Ideally you should balance your 3 phases as close as possible (i.e. move some plugs / lights / appliances around till the 3 phases use about the same energy), then split your panels evenly across the 3 inverters, and install the parallel comms cables so the phases will sync. These inverters can handle max. 3000W (4000W on the new models) of PV, per inverter, so there's no point in having all the panels on a single inverter. You could, however max out the "heavy usage" inverter with PV, but then the other two will most likely draw all it's energy from batteries the whole time - which is why you actually want PV on all 3 inverters.

Fair enough. So let's assume in his setup, the red phase feeds all the plugs in the house, the blue phase feeds the pool pump, irrigation and garage, and the yellow phase feeds the stove, geyser and lights. Then, yes, the 3 inverters will be unbalanced and if one of them use more power than the PV can produce, it would draw from the batteries. Or from Eskom. But in a normal 3phase setup, with 3phase equipment, it would have balanced out evenly.

yea, yea..

The only time it will be out of balance in a 3phase configuration, is when the 3phases are used to run normal 220V appliances. But if he's using 480V / 3phase appliances, it will still balance out evenly between the inverters.

If the 3 inverters are linked together, the load will be split evenly (to a great degree at least) between the 3 inverters.

Yup

Under R5k will be hard to find. I can get you some new one @ R5204.1

where are you based? Do you want second hand, or new?

I would still expect to have seen the right equipment being quoted in the reports, by the experts. Surely the experts would then have said 2x 4Kw inverters and 3x battery banks? It sounds to me like Mart-Mari is being taken for a ride, yet again.

That's not the same system as the report..... The report says 2x 5Kw inverters and 2x battery banks. A single Axper inverter, 12x panels and 12x 250W panels and 12X 100Ah batteries would be at full capacity of the system. Perhaps the 4 independent experts don't really know too much about inverters and solar panels? How do you mistake a single 4Kw axper for 2x 5Kw inverters? 12x 100Ah batteries would give 3x battery banks, not 2.

True, it could possibly very well be fixed, but the report is sketchy and IMO leans more in favor of the new installer than the client. I would: #1 Replace all the cables with the correct cables. #2 Replace all fuses / isolators with the correct type and rating, i.e. DC fuses on the batteries / inverters and AC on the AC side #3 Install more isolators / fuses where needed #4 Add more solar panels, if possible, and move the ones that's in the shade, trim the trees if necessary. If it's behind another building, one would need to either move to another roof, #5 replace the MPPT chargers #6 replace the batteries #7 Obviously supply all the technical material, offer training, suggest regular maintenance, etc. #8 Get someone to sign a COC, preferably the same person / company who signed the original COC. If there's no COC, the client needs to understand that a whole new COC could cost a lot of money, depending on what needs to be fixed / replace in the rest of the house. My one friend spend R70K two years ago whey they sold their house, to re-wire the whole house as everything was sub standard. #9 supply & install battery cabinet, warning labels, instructions for safe disconnect, etc. #10 educate the client on the system, possible safe loads, run times, etc, etc.

I don't think she has Axpert's installed. They keep referring to 5Kw and 10Kw so I'm guessing she has Microcare or other 5Kw inverters which doesn't have built-in MPPT chargers.