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Going Blue!

Featured Replies

OK, so now I'm thinking to go Victron MultiPlus II Inverter 48/3000.

My thoughts are east/west array configuration, but what MPPT would be best so that I can maximum as much solar as possible for as long as possible. 

2 x 150/35?

My west "footprint is smaller than my east footprint, so I most likely will need to use my very big north facing roof

24 minutes ago, Antony said:

OK, so now I'm thinking to go Victron MultiPlus II Inverter 48/3000.

My thoughts are east/west array configuration, but what MPPT would be best so that I can maximum as much solar as possible for as long as possible. 

2 x 150/35?

My west "footprint is smaller than my east footprint, so I most likely will need to use my very big north facing roof

Well, blue+grey could be a good choice. I don´t remember now if there is a Fronius with a pair of MPPTs. I would research it.

Fronius is a wee bit costly compared to MPPT's, no?

On 48v one can have up to 2kw on a 150/35.

So midday one can draw 3kw between the two arrays, if they are positioned properly?

2 minutes ago, The Terrible Triplett said:

Fronius is a wee bit costly compared to MPPT's, no?

On 48v one can have up to 2kw on a 150/35.

So midday one can draw 3kw between the two arrays, if they are positioned properly?

You can use Blue an White as well. Not sure about the cost of 150/35 but you can use longer strings and less wiring and combiners for a GT inverter. 3.3kwp string inverter has dual mppt with each mppt @ 2kwp.

UNO-DM-1.2-2.0-3.3-4.0-4.6-5.0-PLUS_BCD.00647_EN_RevF.pdf

1 minute ago, anotherbrownbear said:

You can use Blue an White as well. Not sure about the cost of 150/35 but you can use longer strings and less wiring and combiners for a GT inverter. 3.3kwp string inverter has dual mppt with each mppt @ 2kwp.

UNO-DM-1.2-2.0-3.3-4.0-4.6-5.0-PLUS_BCD.00647_EN_RevF.pdf

What about the price? I´ve never used it, but could be an alternative. Does it have a pair of MPPTs?

11 minutes ago, anotherbrownbear said:

... cost of 150/35 ...

I guess them to be around R4 000- R4 500.

  • Author
3 hours ago, anotherbrownbear said:

 

No, this is a grid-tie inverter. You already have the Multi-ll for the battery input.

Please excuse my ignorance but why would I have a Multi and a ABB?

Does this mean the Multi is not a "all in one"?

  • Grid input
  • Solar PV input
  • Battery input/charger
  • Load output - All loads and essential loads during power failure

 

  • Author
1 minute ago, anotherbrownbear said:

No, you still need a charge controller or PV inverter for solar input.. But it is grid compliant out of the box.

That would be the MPPT's (2 x 150/53) for the 2 x 2000w solar arrays?

15 hours ago, anotherbrownbear said:

 

No, this is a grid-tie inverter. You already have the Multi-ll for the battery input.

Wait can the inverter then send the power back (just enough so as not to feed in) and use the AC charger of the multi to charge the batteries?

12 hours ago, Antony said:

Please excuse my ignorance but why would I have a Multi and a ABB?

Does this mean the Multi is not a "all in one"?

  • Grid input
  • Solar PV input
  • Battery input/charger
  • Load output - All loads and essential loads during power failure

 

That would be the EasySolar

Which basically already has the :

Multi (Which is a inverter and AC charger)

- BlueSolar MPPT (Solar Input)

- Depending on the module a CCGX for ESS

12 hours ago, Antony said:

Please excuse my ignorance but why would I have a Multi and a ABB?

To also provide an answer: Look at the difference between AC-tied PV and DC-tied PV. Using a Fronius or an ABB is a way of getting your PV in directly onto the AC side (and the Multi can convert that down and charge a battery from it). Using an MPPT instead is a way to get the PV in on the DC side (and the Multi can convert that up and power loads from it). If you're focused more on storage (ie power is mostly used at night) then DC-tied is more efficient. If you're focused more on powering the loads (most power is used as it comes in), then AC-tied is more efficient.

  • Author
2 minutes ago, plonkster said:

To also provide an answer: Look at the difference between AC-tied PV and DC-tied PV. Using a Fronius or an ABB is a way of getting your PV in directly onto the AC side (and the Multi can convert that down and charge a battery from it). Using an MPPT instead is a way to get the PV in on the DC side (and the Multi can convert that up and power loads from it). If you're focused more on storage (ie power is mostly used at night) then DC-tied is more efficient. If you're focused more on powering the loads (most power is used as it comes in), then AC-tied is more efficient.

 

I'm looking at primarily powering daytime loads, but with the benefit of having limited standby for powering lights, etc at night and possibly during load shedding.

But then its efficiency versus costs for "2" systems and the additional space it will occupy, now as @PJJ stated, maybe the EasySolar is the way to go

5 minutes ago, Antony said:

EasySolar is the way to go

Thinking about my setup, and the space it takes, Easysolar seems to be the "easy-er" one to mount.

And it has a 150/70 taking 4000w of panels on 48v. 

Then it is just a case of mounting the panels so that the morning draw is dealt with, no?

6 minutes ago, Antony said:

But then its efficiency versus costs for "2" systems and the additional space it will occupy, now as @PJJ stated, maybe the EasySolar is the way to go 

Indeed. An MPPT is slightly cheaper than a PV-inverter. And with a PV-inverter you have additional issues during extended outages. A PV-inverter only works if it has AC to tie with. When the grid goes down, so does your PV. So you have backup, but no way to use your PV. The way to get around this, is to tie the PV-inverter to the output of the Multi. But that has one additional caveat: The dead battery deadlock. If the battery goes too low the Multi switches off. When the Multi is off, no AC to tie with... no way to use the PV to charge the batteries.

The way to break the deadlock: You either need another AC source (battery), or another charging source (put a small number of panels on a small MPPT).

So the additional caveats plus the additional cost generally means that for a small (residential size) setups, you might be better off taking the efficiency hit and just going with MPPTs (or the Easysolar). For office buildings and large scale things where power is used during the day... you absolutely must go AC-tied.

  • Author
12 minutes ago, The Terrible Triplett said:

Thinking about my setup, and the space it takes, Easysolar seems to be the "easy-er" one to mount.

And it has a 150/70 taking 4000w of panels on 48v. 

Then it is just a case of mounting the panels so that the morning draw is dealt with, no?

It even comes with circuit breakers

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