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Solar Athiest?


Richwost
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This is my situation.  I looked at Solar Power long and hard about 12 months ago and I became more and more unconvinced about solar in my situation.  I have a small 250Ha bush farm on the coast with just indigenous game on it.  So eventually I bought a 20kW quiet low-revving diesel generator which powers everything in my house and I love it.  But… a generator is only 60% of the solution.

If the power goes off when I don’t need power, then I leave the generator OFF.  If we are doing something which does require power, I set the generator to auto, so that it will come on within 10 seconds of Eskom going down.  If I go out for the whole day, I leave the generator off, but if I get back to find Eskom off, I have no lights and no security.  If we are watching TV, the TV goes down and the whole thing has to get rebooted, even if the generator comes on.

When the generator is ON and Eskom comes on again, the generator withholds its power for 1 second while it aligns its sine wave with that of Eskom.  That is enough to upset DSTV and the decoder has to reboot.  The generator then monitors the Eskom power for about 2 minutes and if it is satisfied with the quality of the power, then it powers itself down and returns to standby position to come on again.  At that point I turn it off if I no longer need it to be on standby.

What I want is a strong UPS type system that could keep the following running:

The lights which are LED, mostly 6W, three floodlights of 50W each which I do not have to use. (Est use 300w).  One TV and decoder.  (LED TV) (Est 300w).  Security system (Est 100w).  Victron inverter 1.2 kW (Est 200w) 

Total ….. say 960w per hour - or 4 Amps per hour

I want a system which will power up those items above, when I do not need the generator.  I need at least 12 hours cover - i.e. 48 amp hours minimum. More is better within reason.

When Eskom goes down, the system must seamlessly take over.  If I turn the generator on then the generator most take over and the battery (or batteries) will be charged by the generator.   When Eskom comes back on - while the generator is on - then the system must seamlessly fill the one second gap while the generator aligns its sine wave with that of Eskom. 

Questions:

1.    I believe that a Victron Multiplus 1.2kW is perfect.  Or is it?  I am not quite sure how these things work, but I will have three things delivering 240V AC power:  Eskom, the inverter and the generator.  Can a Multiplus handle all that, or should it be a small Victron Quattro???

2.    I very much like the idea of a Victron “package” where everything works together - even just one 12V Victron Lithium 160Ah battery - even at the high price. 

3    If I have to go for the Victron Quattro, then what is the right size for me? What is the smallest one?  

Once I have filled in the gaps left by the generator, then I will have a perfect system in my opinion - with no panels and no battery bank.  

I am sorry if you feel that I am being a traitor to the world of Solar, but how do you feel about my solution?

I would really appreciate comments - both positive and negative.

Many thanks

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The smallest Quattro is 3KVA, which may or may not be overkill.

Your load sounds like about 1kw, but LED lights don't have a perfect power factor (maybe 0.7, but as bad as 0.2 for MR16 downlights on transformers) and since that makes up most of your load, I think the 1.2kva unit is going to be too small. You want at least the 1.6kva. The 3kva remains the pick of the bunch in my opinion.

Prices are actually quite reasonable at the moment, probably due to the improvement in exchange rate and the fact that Victron has slashed prices. I saw a 3kva Multigrid with two MPPTs for 20k ex VAT the other day. That is insanely good value, though you're not going to have much use for the MPPTs at this stage. The 1.6KVA Compact model was around 16k ex vat until very recently, just to put that into perspective.

The difference between the quattro and the "normal" multiplus is that the quattro has two inputs, one for the grid and one for the generator (normal one has only one input for grid), and it can switch to either, whichever is available, though the priority can be configured. You can also auto-start the generator using the relay on the Multi.

But it sounds to me like you already have a transfer switch with the generator, just that it is a bit slow at 1 second. So you don't really need the Quattro.

The Multigrid I linked above is a version of the Multiplus that has anti-islanding built in. It is meant to be used in a hybrid configuration, mixing solar with grid power together with a CCGX. So that one is also overkill... except at the price it is almost impossible to ignore.

Anyway, you're looking for something between a 1.6kva Multiplus Compact, a 2kva Multi Compact, or a 3kva Multiplus. Normally the 1.6kva would be around 17k, the 2kva just above 20k, and the 3kva is usually around 26.5k... but recently there's been a couple of insane specials. Shop around and pick up a 3kva if you can.

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Hang on, I am confused by the green stripe on that inverter. Normally the green stripe is for the Multigrid. This one is an easysolar though. Might be worth it, just ignore the solar part for now. Add it later once you've come to repentance :-P

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Interesting. You are trying to do the reverse of most people, I.e run on generator or eskom, and then use batteries when either of those fail for form some reason. If you cost it you will find that if you are on a farm eskom tariff, solar is way cheaper than either of the above, and probably 50% cheaper now than when I did those sums.

Once you have batteries and an inverter or ups, it makes 1000%  sense to put up a few solar panels to keep them charged.

How slow revving is your genny? I bet mine is slower.....:lol:

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Using a Multi with a generator is common enough. I believe this use case might be very similar to this one. It could in fact save some Diesel if you do it right. That paper is old(ish), which is why it still talks about the Phoenix Multiplus, but the results are still valid.

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Honestly, either using a UPS or an inverter + battery bank will achieve the same in this case. There's not much that would benefit from a "traditional" UPS, unless you do actually have servers / PC's / etc that need to be able to monitor batteries and shutdown if necessary. You could also probably get away with using some of the cheaper brands, but that would also all depend on what you're prepared to pay + what features you really want / need

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33 minutes ago, SilverNodashi said:

Honestly, either using a UPS or an inverter + battery bank will achieve the same in this case. There's not much that would benefit from a "traditional" UPS, unless you do actually have servers / PC's / etc that need to be able to monitor batteries and shutdown if necessary. You could also probably get away with using some of the cheaper brands, but that would also all depend on what you're prepared to pay + what features you really want / need

For what it's worth, I would rather go for a cheaper brand with full hybrid capabilities and not for a ups as such. At this particular time, Silver is absolutely right, there won't be much of a difference. If circumstances, electricity costs and availability changes in future though, one would be able to add some panels and do not have to worry about replacing equipment again. Who knows, maybe we might just be able, in the not too distant future, to pump into the grid nation wide !!! ( Lol !!)

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The force is strong in this one.

Jip this is a case for a UPS, but having a generator in the mix makes for a very specific type of UPS. Not all UPS'es are generator capable.

And as was said if things change into the future you don't want to go out and buy again. You want to add.

14 hours ago, Richwost said:

... and no battery bank.  

Charging batts with gennie whilst it is running is ingenious as you are using every ounce of each liter of diesel.

The questions to answer also:
What is connected to the inverter - no house, no geyser correct?
What batteries, AGM or lead acid?
Exactly how long must the load be powered without generator?

And I would suggest keep a wide open mind for adding panels ... using a gennie to charge panels if there is ample sun just makes no financial sense at all.

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Only reason that I'm really suggesting a UPS is because it seems that the biggest irritation is that the DSTV computer needs to reboot. The loads are small and the time it has to bridge is small too. A UPS usually has a faster transfer time than most inverters. So if you can get a UPS at a better price it might be the thing to do.

Then again, many inverters make very good UPSes. Both the Axpert and the Multiplus do just fine as UPSes.

This model where you charge a battery bank (for smaller loads) while running the generator (for the larger loads) is of course as old as the mountains. It's what farmers have been doing for ages, especially in the 80s. The generator runs in the morning to pump water and run the big old minus-40 freezer. Tonight the lights and the television run from the batteries.

And because battery storage is cheaper than diesel, it even makes economic sense. It's simply a matter of obtaining enough of it with a big enough inverter to match. A UPS that can carry the load for a certain time period sounds like precisely the right thing. It doesn't have to be blue, but I firmly believe it's the better inverter. I think what might clinch the deal is this: Would you like the inverter to signal to the generator that the batteries are empty and it is time to start? Can your generator do that? If yes, then the programmable features of the Multi will make things so much easier that it becomes a no-brainer. Get a Multi :-)

(Yes, I know the Voltronic has a dry-contact relay too, but I don't think it is as programmable/flexible as the one in the Multi :-) ).

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5 hours ago, plonkster said:

Only reason that I'm really suggesting a UPS is because it seems that the biggest irritation is that the DSTV computer needs to reboot. The loads are small and the time it has to bridge is small too. A UPS usually has a faster transfer time than most inverters. So if you can get a UPS at a better price it might be the thing to do.

Then again, many inverters make very good UPSes. Both the Axpert and the Multiplus do just fine as UPSes.

This model where you charge a battery bank (for smaller loads) while running the generator (for the larger loads) is of course as old as the mountains. It's what farmers have been doing for ages, especially in the 80s. The generator runs in the morning to pump water and run the big old minus-40 freezer. Tonight the lights and the television run from the batteries.

And because battery storage is cheaper than diesel, it even makes economic sense. It's simply a matter of obtaining enough of it with a big enough inverter to match. A UPS that can carry the load for a certain time period sounds like precisely the right thing. It doesn't have to be blue, but I firmly believe it's the better inverter. I think what might clinch the deal is this: Would you like the inverter to signal to the generator that the batteries are empty and it is time to start? Can your generator do that? If yes, then the programmable features of the Multi will make things so much easier that it becomes a no-brainer. Get a Multi :-)

(Yes, I know the Voltronic has a dry-contact relay too, but I don't think it is as programmable/flexible as the one in the Multi :-) ).

Sorry TTT and Plonkster, but I have to inform you, that what you are discussing here, are seamlessly working with the I-meon 9.12. I would therefore think that it would be excactly the same with the 3.6 version and I would guess (I really don't know!) that it might be also true for the Voltronic v-series.  Don't kill me for this one guys, just as a matter of info

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2 minutes ago, Chris-R said:

seamlessly working with the I-meon

As a matter of interest, how adjustable/flexible/programmable is this? I think the Voltronic simply closes the relay when the power goes out, in other words, immediately, and as I understand it that already happens. With the Multiplus you can start based on SoC, Voltage or Load. You can set a minimum runtime (so the engine doesn't shut down too soon after starting). So it would only start the generator after an extended outage.

Thing is, since there is already some controlling machinery present here to auto-start the generator I'm questioning how useful that might be. I think it might be useful if the generator didn't auto-start but rather started on low battery, which is why I added: Might as well use the relay in the BMV then. That's a 2k option rather than a 20k inverter :-)

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I will test the system over the weekend,  but it should start the gennie as soon as grid drops below a certain voltage and will shut it down when it found the grid to be stable again. Will give you feedback somewhere during the weekend

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5 minutes ago, The Terrible Triplett said:

I love this.

From UPS to Victron to Infini solving the problem.

in the end it should be driven by price and preference 2nd.

Hi TTT, I am trying my best to make you a big fat sale !! You know the farmers in RSA is fat cats ! :)

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8 minutes ago, Chris-R said:

the farmers

What amazed me with all their generators, and some of them had huge ones, the UPS'es I sold was for the wifes. No joke. 7de laan.

When the power goes off Jonas must run to start the gennie and by the time it is settled the Wife missed too much already.

So die manne moes mamma happy kry. Enter the UPS'es.

Then one day a few of the manne was watching rugby on one of the farms. Power goes off but DSTV and TV kept going. Then I sold A LOT more. :D

UPS is ideal for certain operations. 1300w inverter is wot, R2k, add 2 x 12v 100ah leisure batteries and you are good to go. 

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2 hours ago, Chris-R said:

Sorry TTT and Plonkster, but I have to inform you, that what you are discussing here, are seamlessly working with the I-meon 9.12. I would therefore think that it would be excactly the same with the 3.6 version and I would guess (I really don't know!) that it might be also true for the Voltronic v-series.  Don't kill me for this one guys, just as a matter of info

Chris, most inverters will work well in this scenario, not just the Axpert, Victron or Imeon ;)

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2 hours ago, plonkster said:

As a matter of interest, how adjustable/flexible/programmable is this? I think the Voltronic simply closes the relay when the power goes out, in other words, immediately, and as I understand it that already happens. With the Multiplus you can start based on SoC, Voltage or Load.

With Axpert it also kicks in (or out) based on SOC

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Many thanks to all of you who replied to my post.  As I said a year ago ("A new installation") this in an incredible place to get advice from some extremely knowlegeable people.

Let me make some comments in point form...

1. Plonkster I have been shopping around for Victron and I find that a "Victron Energy Multiplus Compact 12/1200/50-16 230V VE Bus" I can get for R!2,767 whereas the "Phoenix" 12/1200 I can get for R8,650. There must be a difference, but what is it?  I am not saying that I will get that particular model, but I do like 12V, because I want one 12V Victron Lithium battery.  I would like a 12/1600, 12/2000 or 12/3000.  I think that most of you would disagree with 12/3000, but why? (Anyway I don't think is available in this country)

2. I do not think that a normal (dare I say "cheap"?) UPS is my bag.  I used the DSTV example purely to illustrate that the changeover from generator to Eskom is by no means seamless.  If you are recording the Boks... well maybe you'd be lucky!!  The power could be off for hours - even days.  I certainly would not use the generator just to charge the batteries.   The generator would be used twice a day for a total of about 3 hours  and during that time it would (hopefully) recharge a 50% used Victron Lithium battery.  Maybe not?  Could this be my achilles heel?  If so, I may have to repent after after all and have two panels.

3. I am a firm believer in "less is more".  I would really like to have just one 12V Lithium battery of 160 or 200aH and if necessary 2 good Sunpower panels.  Would that ratio work?

4. On my small farm I have a 50kVA transformer and 3-phase power.  There are 2 houses.  My overhead (excl) is R2000 pm.  There is not even a remote possibility that i would give that up.  The cost of power thereafter is R1.16 per unit (excl).  I regard R1.16 as cheap(ish) power.  Am I wrong?

5. My genny runs at just under 1500rpm DeepBass.  It is a Kipor KDE20SS3 Diesel.  20kVA, Chinese, but I am extremely happy with it.  So quiet that I have to go outside to see if it is running.

6. The battery would power the mostly LED lights (lots of them), the security system (many beams and cameras), the TV systems.  NOT anything particularly power hungry.  The house is double storey - mainly for security reasons.  Maybe I could get away with a cheap UPS, but that is not what I want.  Whatever I have will be used and tested regularly.  Once on, I would expect the system to be able to stay on for 12 hours without being charged. 

7. I used to be a big advocate of Microcare, but I have shifted to Victron.  I have never had either, but just when I was going to buy two inverters from Microcare a year ago, they suddenly went dead quiet.  6 months later they asked me if I was still interested!!!!  I am now Victron and I really don't want to look at anything else.

That's about it for now.  Once again I look forward to your comments...

Many thanks again - Richwost

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