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I received finally received my PCB and my first 2000 Watt unit is working as expected. The final test will be done when the council connects my by directional meter then I can push a fair amount of power back into the grid.  Following is a brief overview of what I refer to as MyBoxOfTrix:

MBOT 1000 - 11000

The inverter comprises of 3 units:

  1. Inverter (grid tie) single or three phase

  2. Off-Line inverter

  3. Control unit.

The inverter is an inverter starting at 1000W. It has the ability to be upgraded to 10000 Watts without loosing any money. Therefore the steps works as follows:

  • 1000 Watt Entry level

  • Upgrade to 2000 Watt we ships a plug-able replacing unit that will do the upgrade +/- 10 minutes work. Can guide over the phone

  • 2000Watt – 3000 Watt Watt we ships a plug-able replacing unit that will do the upgrade +/- 10 minutes work. Can guide over the phone

  • 3000 Watt – 4000 Wat we send a technician to upgrade the main board +/- 1 hour job.

  • 4000 – 5000 Watt we ships a plug-able replacing unit that will do the upgrade +/- 10 minutes work. Can guide over the phone

  • 5000 – 6000 Watt we ships a plug-able replacing unit that will do the upgrade +/- 10 minutes work. Can guide over the phone

  • 6000 – 7000 Watt we ships a plug-able replacing unit that will do the upgrade +/- 10 minutes work. Can guide over the phone

  • 7000 – 10000 Watt we ships a plug-able replacing unit that will do the upgrade +/- 10 minutes work. Can guide over the phone

At no stage does the client loose a single sent except where the upgrade is fro 3000 – 4000 Watt . For this upgrade there is a minimal call out fee. A client does not have buy or sell simply replace upgrade.

The second unit is a small 900 watt single or three phase (300W per phase)unit. This unit can work only in off the grid mode. The combination of 1 & 2 provides a 11Kwatt 3 phase or single phase on/off grid unit.

The third unit is a complete PV battery management system. This I believe is more efficient and functional as a MPPT. The basic unit can control 64 amps solar power and can be expanded to 320 amps. The unit Voltage range is between 12V – 90 Volts DC. The only limit for the voltage is that I prefer for safety reason and regulation to work as an Extra Low Voltage system.

This unit is a complete 3 phase ac meter. Volts, Amps, Kwh Dc Volts, DC Amps. The charging curve is changeable by various parameters in the system. It control a double actuator that when the grid has no voltage this unit will disconnect 4 or 8 320amp actuators to ensure a full disconnect from the grid.

The unit measures does a complete battery evaluation and control. It has 16 48V digital outputs that can drive a relay of 12- 48V 500mA per relay. The controller has the complete interface to do solar tracking and controls the solar movement unit following the sun.

This unit is designed to work off a small alarm type battery. The unit can control 6 different digital outputs by time or voltage.

It will also manage a small RO system.

Plenty more software monitoring build in and does a measurement every 100 micro seconds.

The unit allows a client to start at +/- R 8000 solar (grid tie) and expand to a full 11KWatt on/off grid unit. The 1st unit can be daisy changed and interconnected with a 2 mm communications cable that will allow all units te be managed from a parent unit and the rests are slave units.

Currently I have it assembled outside SA

That is a short overview of my MBOT.

 

 

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Also curious on comparing costs. Like I'm on the hunt for a 5kva inverter unit to suit my needs. I have a seperate MPPT charger currently but that can be changed if I find something more suitable. I want to keep the connection as off grid. I need the charge voltage to reach 57.5 when the Li-on batteries are full, I want to set the battery low voltage cut off to what I want and not a preset voltage . A few configurable relays or outputs dependent on SOC or other parameters . I like the idea of adding on building blocks . So the 5kva axpert is about R9k and from  there price goes up.

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On 2018/09/30 at 12:22 PM, Erastus said:

The second unit is a small 900 watt single or three phase (300W per phase)unit. This unit can work only in off the grid mode. The combination of 1 & 2 provides a 11Kwatt 3 phase or single phase on/off grid unit.

I'm interested in this part, well, in the technical details. It sounds like the 900W unit provides a basic signal for the rest to tie with. The reason I am interested in this is the ratio is a cool 10:1. For Victron equipment the rule is 1:1, the transistors inside the unit has to be able to handle all the power the PV-inverter tied to it can make.

In fact, my overall interest in this is mostly for the technical side, the how of the thing, because it sounds like it's rewriting the rule-book, and that doesn't happen often.

On the same topic, I realised this morning that the MPPT vs no-MPPT discussion is a bit like manual vs automatic transmissions. Engineering Explained put up a video a few days ago explaining why you should prefer an automatic (at least nowadays) and one reason he mentioned is that the automatic transmission is a torque converter: It swaps power for torque and the other way round, so it allows slow crawling for example. Of course some of the power is lost (the transmission fluid heats up) in conversion, but in those conditions where the engine is badly matched with the load (when you pull away for example) it is brilliant. Compared to the fluid coupling, there is no torque conversion in a normal dry clutch, just like there is no power conversion in a PWM controller. Nevertheless, for an insanely long time manual transmissions were more efficient, and they are still cheaper to maintain :-)

Edited by plonkster
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19 hours ago, plonkster said:

I'm interested in this part, well, in the technical details. It sounds like the 900W unit provides a basic signal for the rest to tie with. The reason I am interested in this is the ratio is a cool 10:1. For Victron equipment the rule is 1:1, the transistors inside the unit has to be able to handle all the power the PV-inverter tied to it can make.

In fact, my overall interest in this is mostly for the technical side, the how of the thing, because it sounds like it's rewriting the rule-book, and that doesn't happen often.

On the same topic, I realised this morning that the MPPT vs no-MPPT discussion is a bit like manual vs automatic transmissions. Engineering Explained put up a video a few days ago explaining why you should prefer an automatic (at least nowadays) and one reason he mentioned is that the automatic transmission is a torque converter: It swaps power for torque and the other way round, so it allows slow crawling for example. Of course some of the power is lost (the transmission fluid heats up) in conversion, but in those conditions where the engine is badly matched with the load (when you pull away for example) it is brilliant. Compared to the fluid coupling, there is no torque conversion in a normal dry clutch, just like there is no power conversion in a PWM controller. Nevertheless, for an insanely long time manual transmissions were more efficient, and they are still cheaper to maintain :-)

My drive is for maximum efficiency @ minimum cost. If one has the opportunity to develop "from scratch" one should make use of best practices and not kill the customer with unnecessary  cost on electronic equipment that has an overhead. Especially when the cost is that high. I fully under stand the design and reason of the MPPT. In my system it is a total waste of money and a useless piece of equipment. Same for battery stuff and all the electronics so often referred to that is that expensive.

It is easy to cheat with software.

In electronics  it is important for me to ensure that a proper balanced system is designed where no additional equipment is required. In inverters this is a little tricky. VAR are import and as you mentioned before the quadrant of operation. Then to create a product that is not tied to a freq but rather Max output the ball game changes.

Therefore I divided the product into 3 parts ( to make live easy). Then it becomes like Lego. Little building blocks and you can start small and end up with a huge system. With my system I do all with software more accurate as much as I can. Software is a big cheat and you can make it look right even if it is not right specification.  Simple if Batt are well looked after and system is working well. To do automated maintenance is better than to trust a human with repetitive brain dead tasks. (unless) Therefore build the Batt test into the controller and then an all in one unit is very easy manageable and extremely cost effective.

The power side at full load has an efficiency of just over the 99% which is pretty good. But then come the trouble.

In order to do this I made use of a dual core RISC processor with 32 analogs 3 parallel voltage references  shared ram ONLY to handle the three phases, power limit, over Voltage protection and what is needed in an inverter.The reason why I "stirred" a bit re the MPPT is to understand the perception on MPPT. That thought me a lot.Plonkers that verbal exercise meant a lot to me. I might have upset a few people but then the truth came out. You can be glad you did not take up the chalange it was a wise (scared?) move. I am sorry I missed out on an ice bucket.

To be fair I understand the full operational aspects of a MPPT and do find it a designed to glue miss matched mess of equipment together. That is seen from a hard core electronic design perspective.

The idea with this design was not to stand in a que but to create a new one to the benefit of all of us. The export market is more attractive and there one has to be very cost effective. In SA the perception is the more expensive and more gadget the better the product.

If I can achieve to maximize the diversion of capitol from the City of Cape Town I have achieved somthing.

That is my take on toy toy.  Force them to rethink what they do. At least then there is less to steel.

Hope it makes more sense and if I offended you I do apologize it was not my intention but more to understand the perception on MPPT and other expensive equipment.  Your perception on manual and auto in my humble opinion is incorrect.

The sole purpose of an MPPT to to fix a terrible miss match mess at the cost of $ and ...  Not a clever system.

 

 

 

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On 2018/10/03 at 7:01 PM, SilverNodashi said:

Nice!

 

What prices would I be looking at for the various models?

Will start from +/- R7000 as I am running small manufacturing at this moment the moment I increase the volume I recon it should start at +/- R5000 3KW +/- R7000 and 10 Kw +/- R 18 - 20 000.
Entry level we are looking at as I believe it is to expensive. The ideal would be to start at R4500. My opinion for a grid tied unit you then only require solar panels. Bring the cables to the system and it works for you. I am sure once we get the export side working as it is 50 /60 Hz 110 / 240V plug and pray the cost will drop. Interesting at this moment manufacturers charge me R20 000 for 4 power boards. I import them at +/- R700 a board. I am in the test phase and as soon as I am out of it I will know exactly where I stand with it.

There will also be two "boxes" one from mild steel and one from stainless for the coastal areas.

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2 hours ago, Erastus said:

Interesting at this moment manufacturers charge me R20 000 for 4 power boards. I import them at +/- R700 a board.

Just read an article where SuperMicro's had a chip on them that allowed them to be hacked. In that article, a distribution company not aware of the chip that made the servers hackable, sold them at a whopping 70% markup. 

2 hours ago, Erastus said:

In SA the perception is the more expensive and more gadget the better the product.

I have seen this many times. Damn good marketing if you ask me, when you think 70% markup. :-)

@Erastus a interesting thing I am noticing, the smaller the panel, the more expensive they are. Like a 150w panels is blerrie expensive. 355w panel at half the price per watt.

I see 405w panels are coming.

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3 hours ago, The Terrible Triplett said:

Just read an article where SuperMicro's had a chip on them that allowed them to be hacked. In that article, a distribution company not aware of the chip that made the servers hackable, sold them at a whopping 70% markup. 

I have seen this many times. Damn good marketing if you ask me, when you think 70% markup. :-)

@Erastus a interesting thing I am noticing, the smaller the panel, the more expensive they are. Like a 150w panels is blerrie expensive. 355w panel at half the price per watt.

I see 405w panels are coming.

Nie so seker van die stelling nie.  Eerstens spaar ek omtrent R4000 op MPPT. Die MPPT maak groot verskil in kostes. Ek kan 32 panele loop op een  raam en ....  Hoeveel MPPT sal jy benodig teen watter koste vir 32 panele.  Dan werk die verliese uit. As jy 100% loop dan is dit so 2% laer kan dit tot 7% gaan. Doen die berekeninge sal intresant wees. Ek kon nog nie 'n goedkoper  gelyke kry nie.
Dan moet jy onthou 32 panele op my tracker is gelykstaande aan 48 statise panele.

Nie so seker van die stelling nie.  Eerstens spaar ek omtrent R4000 op MPPT. Die MPPT maak groot verskil in kostes. Ek kan 32 panele loop op een  raam en ....  Hoeveel MPPT sal jy benodig teen watter koste vir 32 panele.  Dan werk die verliese uit. As jy 100% loop dan is dit so 2% laer kan dit tot 7% gaan. Doen die berekeninge sal interessant wees. Ek kon nog nie 'n goedkoper  gelyke kry nie.
Dan moet jy onthou 32 panele op my tracker is gelykstaande aan 48 statiese panele. Ek meen dit sal meer 'n refleksie wees as jy die twee “volle sisteme” wil vergelyk.

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33 minutes ago, Erastus said:

Eerstens spaar ek omtrent R4000 op MPPT. 

Where did I speak of MPPT's in my post?

My point was / is, that the panels are getting bigger and bigger ito volts and amps.

So to match these bigger panels with a 48v battery system, forget 12/24v as their Vmpp are like 40.6, Voc 49.3 - and too low for a 48v system with one panel and in series far too high.

Does that have an effect or not, on your design?

Because to get smaller wattage panels are getting interesting, and if you get, they are like R10 per watt versus quite a few RAND less per watt for larger wattage panels.

 

 

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6 minutes ago, The Terrible Triplett said:

Does that have an effect or not, on your design?

I'm still not fully sure about how the design works and how it slots into that control unit with the 16 gpios. The only thing I can so far see that makes some sense is that if you series 2 x 60-cell panels, then you do get a voltage quite close to the battery voltage, and so your voltage efficiency should be quite good. If my understanding of that is correct, then on average there will be a 5%-10% voltage difference between battery and PV, and hence a similar voltage inefficiency. It may well be that at such a low value the MPPT doesn't make financial sense, especially since an MPPT is between 95% and 97% efficient, so the improvement is going to be single digits.

But you are right when you point out that this rather locks you into always using 60-cell panels. Again... if we understand this correctly.

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4 minutes ago, plonkster said:

single digits

WEeelll, two panels at Vmp gives you 60V. If the battery is at 48V, then the voltage efficiency is 48/60 = 80%, and the MPPT gets you back 95% of that, so 0.95*20 = 19%. If the battery is quite full (absorbing at 58V for example), then the voltage efficiency is 58/60 = 97%, and the MPPT gets you back 95% (best case scenario) of the lost 3%, that's 2.8%. But at this level the MPPT is most likely not going to run at high efficiency (PWM ratio being towards full power) so likely the improvement will be zero for all practical purposes. So your efficiency will be between 80% and 97% (aka on par with MPPT at the top end), and the average will depend on how much time you spend at what voltage.

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5 hours ago, Erastus said:

Nie so seker van die stelling nie.  Eerstens spaar ek omtrent R4000 op MPPT. Die MPPT maak groot verskil in kostes. Ek kan 32 panele loop op een  raam en ....  Hoeveel MPPT sal jy benodig teen watter koste vir 32 panele.  Dan werk die verliese uit. As jy 100% loop dan is dit so 2% laer kan dit tot 7% gaan. Doen die berekeninge sal intresant wees. Ek kon nog nie 'n goedkoper  gelyke kry nie.
Dan moet jy onthou 32 panele op my tracker is gelykstaande aan 48 statise panele.

Nie so seker van die stelling nie.  Eerstens spaar ek omtrent R4000 op MPPT. Die MPPT maak groot verskil in kostes. Ek kan 32 panele loop op een  raam en ....  Hoeveel MPPT sal jy benodig teen watter koste vir 32 panele.  Dan werk die verliese uit. As jy 100% loop dan is dit so 2% laer kan dit tot 7% gaan. Doen die berekeninge sal interessant wees. Ek kon nog nie 'n goedkoper  gelyke kry nie.
Dan moet jy onthou 32 panele op my tracker is gelykstaande aan 48 statiese panele. Ek meen dit sal meer 'n refleksie wees as jy die twee “volle sisteme” wil vergelyk.

Instaleer en toets by my

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9 hours ago, Erastus said:

Dan moet jy onthou 32 panele op my tracker is gelykstaande aan 48 statiese panele.

Sitting here tediusly matching panels and volts / amps ... the lower the volts and the further away the tracker / fixed array is, the bigger the volt loss = the lower the amps.

4mm2 wire is quite a bit cheaper than 16mm2 wire. Using Sonosolar's prices (which are not cheap):
4mm2 = R 10.35 per meter incl VAT = 40m (20m per length) = R414.00
16mm2 = R 34.50  per meter incl VAT = 40m (20m per length) = R 1 380.00

 

9 hours ago, Erastus said:

Dan moet jy onthou 32 panele op my tracker is gelykstaande aan 48 statiese panele.

Panels - what size? 275 x 48 = 13.2kw or 32 x 275 = 8.8kw
So static it is 33 x 400 = 13.2kw OR 22 x 400 - 8.8kw ... both at a moerse high voltage = thin wire.. :-) 

I do concede that on these high kw arrays Victron controllers will be expensive, as will Morningstar TRISTAR MPPT 600V and Outback FLEXmax 100 ... Outback looking quite awesome in their specs.

And I suspect, brand new tracker installed by professionals is going to be more than a MPPT and more panels on a fixed array.
And if you have some of the panels facing East and West on smaller controllers ... 

 

We must not get confused and mix and match MPPT and a tracker and what what. Combination must be:
Tracker + MBB or Tracker + MPPT.
Not MBB on a tracker compared to a fixed array with a MPPT.

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15 hours ago, plonkster said:

WEeelll, two panels at Vmp gives you 60V. If the battery is at 48V, then the voltage efficiency is 48/60 = 80%, and the MPPT gets you back 95% of that, so 0.95*20 = 19%. If the battery is quite full (absorbing at 58V for example), then the voltage efficiency is 58/60 = 97%, and the MPPT gets you back 95% (best case scenario) of the lost 3%, that's 2.8%. But at this level the MPPT is most likely not going to run at high efficiency (PWM ratio being towards full power) so likely the improvement will be zero for all practical purposes. So your efficiency will be between 80% and 97% (aka on par with MPPT at the top end), and the average will depend on how much time you spend at what voltage.

 

BatCharCurv.gif.4efb87b04935a71331d00e497a320394.gif

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6 hours ago, The Terrible Triplett said:

Sitting here tediusly matching panels and volts / amps ... the lower the volts and the further away the tracker / fixed array is, the bigger the volt loss = the lower the amps.

4mm2 wire is quite a bit cheaper than 16mm2 wire. Using Sonosolar's prices (which are not cheap):
4mm2 = R 10.35 per meter incl VAT = 40m (20m per length) = R414.00
16mm2 = R 34.50  per meter incl VAT = 40m (20m per length) = R 1 380.00

 

Panels - what size? 275 x 48 = 13.2kw or 32 x 275 = 8.8kw
So static it is 33 x 400 = 13.2kw OR 22 x 400 - 8.8kw ... both at a moerse high voltage = thin wire.. :-) 

I do concede that on these high kw arrays Victron controllers will be expensive, as will Morningstar TRISTAR MPPT 600V and Outback FLEXmax 100 ... Outback looking quite awesome in their specs.

And I suspect, brand new tracker installed by professionals is going to be more than a MPPT and more panels on a fixed array.
And if you have some of the panels facing East and West on smaller controllers ... 

 

We must not get confused and mix and match MPPT and a tracker and what what. Combination must be:
Tracker + MBB or Tracker + MPPT.
Not MBB on a tracker compared to a fixed array with a MPPT.

Kom bewys my verkeerd die offer is nie terug getrek nie. Ek nooi jou uit

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11 hours ago, Antony said:

Instaleer en toets by my

Ek wag vir parte Chinese vakansie het my terug gesit.

Ek het probeer my PCB in SA te vervaardig maar hulle vra R20 000 vir 5 borde. Van China kry em 10 borde vir $360 USD.

Ek het klein 2Kw wat jy kan gebruik en wanneer die ander eenhede reg is sal ek dit op my kostes uit ruil. Die eenheid vat jy net 2 x 260W panele in serie en in die inverter in. Niks anders nie.

Jy kan ook 3 panele in serie sit vir 90V.  Dan is die effektiwiteit beter.   Dan as jy 4 de koop sit jy hulle in parallel.

Jy moet in groepe van 2 of 3 werk.

Ek sal voorstel jy stop op 8 panele (4  groepe in parralel ). Dit gee jou 2Kw. As jy batterye wil by sit sal my beheerder jou R1500 kos vir 24 panele. Grid tie eenheid kan jy kry vir R5K
Wanneer die ander eenheid reg is ruil ek die een uit vir jou en gee 'n 3Kw eenheid in plek van die 2Kw geen ekstra kostes nie. Ek sal dit courier na jou en die een terug courier op my kostes.

Ons sou die eenhede gebruik het vir ons instelasies. 10Kw is 3 fase en baie meer sagteware in vir remote maintenance en kan begin by 1Kwatt en verloor nie $ as jy op gradeer nie.

Jy kan to 8 panele koppel daarna mors jy. Jy het geen MPPT of iets nodig nie.  Pos en Neg draad van die panele tot in jou eenheid. Dis dit KISS.

Die eenheid loop 100% wanneer daar son is en is 'n dom eenheid. Niks fancy op hom nie.

Jy het geen bedrading nodig nie jy pluk dit in by 'n muur prop. Die idee was om geen COC te kry nie vir koste besparing ens.

Die is 'n werk esel en jy instaleer en vergeet van hom.

Nie ons ontwerp nie maar 'n soort gelyke eenheid maar kleiner.

Om op te som:
'n 2Kw grid tie inverter met beheerder R 6500 as jy  batterye wil by sit.  Jy benodig geen MPPT en geen ander fancy toerusting vir battery wat ook al nie.

Sonder batterye R 5000 vir 2KW eenheid.

Sonder krag en die eenheid skakel af dit is wat die wet vereis anders het jy ander toerusting nodig.
Jy het my email as jy my direk wil koppel.

Die vraag nou aan die ander is sit asb 'n 2Kw sisteem aan mekaar sit en gee vir my pryse. Dan begin ons hier vergelyk.

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Vir Plonkster en TTree oils klop die asb:

1 x 2Kwatt Grid Tie inverter      R 5 000

1 X 24 Controler  R 1500

8 X R 1350  260W                    R 10 800

En jy het 2Kw Grid tie wat op die peak van die dag vir jou 2Kwatt.

Doen asb dieselfde met julle fancy 2Kw eenhede.  MPPT en watse goeters ook al. Moet my nie leer van krag nie ek ontwerp industriele sisteme en databasise my lewe lank so ek verstaan van verskillende  vereistes en so meer. Die oefening is koste per Kwh. As jy hoer in Kwh gaan moet jy versigtig wees want 4Kw inverter kos nie R10 000 nie.

As jy batterye wil by sit die beheerder kan vir jou lead xxxx batterye 100% bestuur ens tot en met 300 amps. 
Nou vra ek vir julle sit vir my dieselfde sisteem by mekaar met julle goeters en gee asb vir my daardie 10% ekstra KW wat plonkers na verwys. Doen die bereken asb met MPPT en al daardie fancy goeters en gee asb vir my 2Kw. As jy wil groter panele vat bV 350W die eenheid kan dit hanteer. Maks inputV is 93V

Talk is cheap money buys the Whiskey.   

 

Klop my en ek vra onverskoning

 

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Kom ek doen nou dieselfde oefening met Solar tracker:

2Kw                   R   5000

Solar Tracker   R   7500  kan tot en met 24 panele vat begin by 8.

8 Panele           R 10800

Beheerder        R  1 500

Totaal              R 24 800 

Die sisteem lewer  meer as 17 Kwh op 'n gewone dag. Sit enige kombinasie van batterye by en ek hanteer dit vir jou. Bedrading en kostes werk dieselfde uit.  Dus gee nou asb vir my meer KwH met julle sisteme met die MPPT ens.  Ek persoonlik kry ek meer as 17Kwh per dag met my 8 panele.

6 235W en 2 260W.

Ek daag julle uit. Gee vir my die 10% meer krag soos julle sê vir minder R.  Dit is nou vir dieselfde sisteem met of sonder tracker. Ek het 4 200amp uur batterye wat ek laai ens. Gebruik enige sisteem wat julle het en klop my asb.

En baie belangrik sit julle pryse by vir die sisteem soos julle dit voorwstel. Al daardie fancy batt goeters , MPPT en en en . In my geval het ek 3Kwatt inverter nie grid tie nie. Hy loop teen 75% van 7 uur soggens tot 7 uur saans op solar.

Bereken 'n sisteem se kostes  met al daardie wonderlikke toerusting vi 'n  +/- 2Kwatt ek sal die inverter prys aan pas as julle bv net 3Kw kan verskaf.

Ek verstaan 100% jy kan nie tracker vergelyk met nie tracker nie. 

Maar klop die pryse, die krag wat ek oes en ....... 

Volgens julle met  MPPT kry julle minstens 2.3Kw van 2Kw panele.

As ek reg verstaan kry julle > 14% meer krag met MPPT.  Dus in 'n gewonde dag moet jy meer as 20Kw oes.

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19 hours ago, plonkster said:

WEeelll, two panels at Vmp gives you 60V. If the battery is at 48V, then the voltage efficiency is 48/60 = 80%, and the MPPT gets you back 95% of that, so 0.95*20 = 19%. If the battery is quite full (absorbing at 58V for example), then the voltage efficiency is 58/60 = 97%, and the MPPT gets you back 95% (best case scenario) of the lost 3%, that's 2.8%. But at this level the MPPT is most likely not going to run at high efficiency (PWM ratio being towards full power) so likely the improvement will be zero for all practical purposes. So your efficiency will be between 80% and 97% (aka on par with MPPT at the top end), and the average will depend on how much time you spend at what voltage.

 

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On 2018/10/04 at 9:43 AM, plonkster said:

I'm interested in this part, well, in the technical details. It sounds like the 900W unit provides a basic signal for the rest to tie with. The reason I am interested in this is the ratio is a cool 10:1. For Victron equipment the rule is 1:1, the transistors inside the unit has to be able to handle all the power the PV-inverter tied to it can make.

In fact, my overall interest in this is mostly for the technical side, the how of the thing, because it sounds like it's rewriting the rule-book, and that doesn't happen often.

On the same topic, I realised this morning that the MPPT vs no-MPPT discussion is a bit like manual vs automatic transmissions. Engineering Explained put up a video a few days ago explaining why you should prefer an automatic (at least nowadays) and one reason he mentioned is that the automatic transmission is a torque converter: It swaps power for torque and the other way round, so it allows slow crawling for example. Of course some of the power is lost (the transmission fluid heats up) in conversion, but in those conditions where the engine is badly matched with the load (when you pull away for example) it is brilliant. Compared to the fluid coupling, there is no torque conversion in a normal dry clutch, just like there is no power conversion in a PWM controller. Nevertheless, for an insanely long time manual transmissions were more efficient, and they are still cheaper to maintain :-)

I'm interested in this part, well, in the technical details. It sounds like the 900W unit provides a basic signal for the rest to tie with. The reason I am interested in this is the ratio is a cool 10:1. For Victron equipment the rule is 1:1, the transistors inside the unit has to be able to handle all the power the PV-inverter tied to it can make.

When you're good you're good    Bietjie boere ingils. B). Is maar net die goeters en speel blokkies wat ons nou kan gebruik.  Die hoof inverter loop teen 99% doeltrefendheid as jy hom reg koppel.  Baie belangrik die eenheid wil werk. Hy kan af val tot 87% as hy poer.

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47 minutes ago, Erastus said:

vir minder R

Well that's not fair... :-)

I showed you my math. I even conceded the financial argument. Now show me what I am getting wrong.

By disregarding the voltage and focusing on amps, as you have consistently done, you skew your efficiency calculations. I find it very hard to argue with you when we cannot agree on this, something which I would assume would be uncontroversial to anyone with the level of experience you portray otherwise.

I'll continue to hold for a better technical breakdown.

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I am sorry guys, but this has to stop. Erastus you are arguing something you cannot prove, we have offered you the opportunity to test and you made agreements to arrange it but never came back with answers. No extended debate is good for the forum and seeing that I did receive some complaints about the atmosphere the previous discussion about this created, I have no other option as to lock this thread. 

You are more than welcome to contact me with some prove of your claims, but this tread in not going anywhere.

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