Solar uppgrade

[tuk75]

Hi guys,

Need some expert help to my solar installation. What I have today is 9 x 380 W and a Sofar 3.2 inventer.

Panels are east-south direction, max production 17-19 KwH per day, ROI about 2 years.

I have a roof south-west direction with place of 5 panels 550 W or maybe 620 W.

I have in mind a Anern 10.2 or PowMr 10.2 inverter with 2 MPPTs , but I am concern if the MPPTs will work with different volts and amps without problems.

The alternative is 2 parallel inverters but it’s difficult to find 5 KwH hybrid inverters for a acceptable price.

The plan is to get batteries after a while, to be completely independent of PEA.

Thanks in advance

T.

[Crossy]

Generally, inverters with multiple MPPT inputs allow them to work independently, so different voltages are quite happy.

 

Best to download the manual for your proposed inverter to check.

 

Also, if you intend adding storage "later" do check your inverters can run without batteries (not all do).

 

We are also in the process of upgrading and I'm going for 3 x Deye 5kW hybrid units running in parallel for a total of 15kW coupled to 70kWh of 48V LiFePO4 storage. At about 45kBaht a pop the Deye units are not exactly cheap, but they are a well-known and respected brand with (apparently) reasonable support. 

 

 

 

[Pink7]

46 minutes ago, tuk75 said:

Hi guys,

Need some expert help to my solar installation. What I have today is 9 x 380 W and a Sofar 3.2 inventer.

Panels are east-south direction, max production 17-19 KwH per day, ROI about 2 years.

I have a roof south-west direction with place of 5 panels 550 W or maybe 620 W.

I have in mind a Anern 10.2 or PowMr 10.2 inverter with 2 MPPTs , but I am concern if the MPPTs will work with different volts and amps without problems.

The alternative is 2 parallel inverters but it’s difficult to find 5 KwH hybrid inverters for a acceptable price.

The plan is to get batteries after a while, to be completely independent of PEA.

Thanks in advance

T.

I was looking into same type inverters and also looked into that size inverter but ended up with 2 x Growatt 5000 and very happy with the decision.

 

Pink

[tuk75]

I am very happy with my "Cheap Charlie" investment for 2 years ago. Deye inventers sounds little bit expensive but I will look as well as Growatt.

I have a 3 phase supply, but I am using it like a 1 phase. 

I am only using excess money from my pension, not touching my savings. Investments goes on my budgett, but the electric bill is on wifes budgett.

I will update when I have bought some new inverters or panels.

Thanks.

T.

[Crossy]

3 minutes ago, tuk75 said:

Deye inventers sounds little bit expensive but I will look as well as Growatt.

 

Growatt do have a big following, pretty good bang-for-the-buck but support appears to be somewhat, er, "variable".

 

[Pink7]

36 minutes ago, Crossy said:

 

Growatt do have a big following, pretty good bang-for-the-buck but support appears to be somewhat, er, "variable".

 

Yes Crossy have some point on this. Growatt is a midway solution.. First i was tempted to go cheaper but I very happy i paid a bit more and got growatt. I think prices now are mid 20k or so..

 

Pink

[BritManToo]

4 hours ago, tuk75 said:

Hi guys,

Need some expert help to my solar installation. What I have today is 9 x 380 W and a Sofar 3.2 inventer.

Panels are east-south direction, max production 17-19 KwH per day, ROI about 2 years.

I have a roof south-west direction with place of 5 panels 550 W or maybe 620 W.

I have in mind a Anern 10.2 or PowMr 10.2 inverter with 2 MPPTs , but I am concern if the MPPTs will work with different volts and amps without problems.

The alternative is 2 parallel inverters but it’s difficult to find 5 KwH hybrid inverters for a acceptable price.

The plan is to get batteries after a while, to be completely independent of PEA.

Thanks in advance

T.

Why not just buy another 5kw hybrid and run upstairs on one, and downstairs on the other. Then no worries about different strings on different PV voltages 

[tuk75]

As BrittManToo suggest why not separate inverters, The only problem is that Sofar is not hybrid.

It’s a pity not to use the Sofar. I am thinking of using Sofar as  the last inverter for daytime use with no export on. Connecting a Hybrid inverter to the same phase primarily to charge batteries or to export and to power up the house nighttime. In my mind it should work but please give your opinion.

My 6000 W water heater I anyhow connect to a separate phase. With two separate inverters it would give me a bigger choice of inverters.

[McTavish]

20 hours ago, Crossy said:

Generally, inverters with multiple MPPT inputs allow them to work independently, so different voltages are quite happy.

 

Best to download the manual for your proposed inverter to check.

 

Also, if you intend adding storage "later" do check your inverters can run without batteries (not all do).

 

We are also in the process of upgrading and I'm going for 3 x Deye 5kW hybrid units running in parallel for a total of 15kW coupled to 70kWh of 48V LiFePO4 storage. At about 45kBaht a pop the Deye units are not exactly cheap, but they are a well-known and respected brand with (apparently) reasonable support. 

 

 

The DEYE hybrids are good.  We installed a 10kw/3phase unit 10 months ago.  ROI approx 5.5 years, though batteries would have extended that considerably.  I'm hoping/waiting for a price reduction in DEYE LifePo4, or a reliable alternative such as sodium, as we seldom use more than 6kwh overnight.

[FlorC]

Where do you buy these inverters like Growatt ?

[tuk75]

Lazada, Shopee, Google is your friend

[lom]

10 hours ago, FlorC said:

Where do you buy these inverters like Growatt ?

Crossy recently advertised two for sale:

 

[FlorC]

22 hours ago, tuk75 said:

Lazada, Shopee, Google is your friend

I would not buy such expensive things via lazada or shopee.

Global house has a limited selection and expensive.

(No , google is not my friend)

[KhunLA]

1 hour ago, FlorC said:

I would not buy such expensive things via lazada or shopee.

Global house has a limited selection and expensive.

(No , google is not my friend)

Deye does have authorize reseller in TH, and I'd be suspicious of anyone selling Deye inverters for less.  Always good to contact and verify information 

 

[FlorC]

^ Thanks.

Wow , those are not cheap.

Hybrid means with solar and batteries ?

I should open another thread about this , but 2 x 12000 BTU (inverter)

aircons on one 5KW inverter without batteries , possible ?

Just to have "free" aircon during the day that I can leave on even when I'm not home.

Edited May 19 by FlorC

[KhunLA]

38 minutes ago, FlorC said:

^ Thanks.

Wow , those are not cheap.

Hybrid means with solar and batteries ?

I should open another thread about this , but 2 x 12000 BTU (inverter)

aircons on one 5KW inverter without batteries , possible ?

Just to have "free" aircon during the day that I can leave on even when I'm not home.

Hybrid cost a bit more, but if you know not going to install batteries, then not really necessary.   Once the inverters are up to temp, they draw very little electric, compared to any older, non inverter.   

 

We run 2 inverters ACs during the day (13 & 24k BTU), with both on now, and fan on auto, high fan now, as just turned 2nd one (24k) on, so rooms haven't equalized yet, so both running at max, and only drawing 3.6kWh total in the house.   That's 2 frigs, 2 laptops, one 65" TV, and the 2 ACs, @ 27C, auto/high fan.

 

Pause in typing, and doing something ... 8 ish minutes later and house up, or down to temp, and now drawing about ~1.5kWh.   TV draws 100w, frigs, when cycling about 250w, laptops aren't worth mention.   Rest is ACs, and draw -500w to 3kWh depending if fans are running on high.

 

[FlorC]

^  No I don't want batteries , they are expensive and I don't want my house in an unextinguishing Lithium fire .

 

With no batteries , do inverters switch off when the solar panels can't deliver enough power ?

Or is the output less than 230 V AC in that case which could be bad for the aircons.

 

If I overdimension the solar panels too get enough power even when there are clouds , is it bad that 

they don't work at full capacity , like producing 5 kw when I only take 2 KW ?

What if in Thai "winter" they are producing power but I don't need it (cool enough to not use the aircons).

 

Do all solar panels already have a diode to protect them against current going back to them 

like when other panels produce more power and a higher voltage than a panel in the shade ?

 

Do you trust those inverters enough to deliver power to expensive appliances like computers or tv's ?

 

 

[BritManToo]

5 hours ago, FlorC said:

^ Thanks.

Wow , those are not cheap.

Hybrid means with solar and batteries ?

I should open another thread about this , but 2 x 12000 BTU (inverter)

aircons on one 5KW inverter without batteries , possible ?

Just to have "free" aircon during the day that I can leave on even when I'm not home.

My 5k5 hybrid was 13kbht delivered, been working nearly 2 years now without problems.

Slightly different now 6k2 at 13k5bht.

https://www.lazada.co.th/products/anern-35kw36kw55kw62kw-24v48v-100a-mppt-220vac230vac-offon-grid-hybrid-inverter-i3481076370-s19883486768.html?

 

If PV not supplying enough, it just tops up from the grid.

 

Edited May 19 by BritManToo

[FlorC]

15 hours ago, BritManToo said:

My 5k5 hybrid was 13kbht delivered, been working nearly 2 years now without problems.

Slightly different now 6k2 at 13k5bht.

https://www.lazada.co.th/products/anern-35kw36kw55kw62kw-24v48v-100a-mppt-220vac230vac-offon-grid-hybrid-inverter-i3481076370-s19883486768.html?

 

If PV not supplying enough, it just tops up from the grid.

 

Weird : To start the inverter normally. The recommended solar panel voltage is 300V-400V, the maximum is not more than 500V.

But : High efficiency pure sine wave inverter; Wide PV input range (90Vdc -500Vdc).

And: The power of the inverter must be at least three times the rated power of the induction loading device.

 

I don't know much about solar systems. So paralleling solar panels is not done ?

You guys usually use 48 V Lithium as back up , so the inverter converts the higher DC voltage (panel in series),

to 230 V ac to convert it down to 48 dc to charge the batteries ? What a waste. 98 % efficiency is doubtful too.

[KhunLA]

29 minutes ago, FlorC said:

I don't know much about solar systems. So paralleling solar panels is not done ?

You guys usually use 48 V Lithium as back up , so the inverter converts the higher DC voltage (panel in series),

to 230 V ac to convert it down to 48 dc to charge the batteries ? What a waste. 98 % efficiency is doubtful too.

I have to plead total ignorance when it comes to most thing electrical, why use of the installer.

 

Here's specs for our inverter & panels:

SUNTECH SOLAR 540 WP

Deye 8kW Inverter

Edited May 20 by KhunLA

[Muhendis]

46 minutes ago, FlorC said:

Weird : To start the inverter normally. The recommended solar panel voltage is 300V-400V, the maximum is not more than 500V.

But : High efficiency pure sine wave inverter; Wide PV input range (90Vdc -500Vdc).

And: The power of the inverter must be at least three times the rated power of the induction loading device.

 

I don't know much about solar systems. So paralleling solar panels is not done ?

You guys usually use 48 V Lithium as back up , so the inverter converts the higher DC voltage (panel in series),

to 230 V ac to convert it down to 48 dc to charge the batteries ? What a waste. 98 % efficiency is doubtful too.

There are all sorts of different "inverters" to choose from.

I placed quotation marks on the word because, for contributors on this forum, the inverter encompasses an off the shelf all-singing-all-dancing easy but often expensive solution to solar power.

Inside the "inverter" will be a charge controller or two to which the solar panel array is connected. 

Output from the charge controller is suitable for charging batteries (generally 48v) and feeding power to the inverter.

Some "inverters" can accept input from PEA et.al. for the purpose of running the loads when there is not enough sun and maybe charge the batteries.

Also some inverters can export power to PEA et. al. via this connection.

The output of the inverter section is 220 or 230vac and capable of delivering power to the house electrical circuits.

The inverter section will be capable of short duration overloads of double the normal power for several hundred milliseconds.

 

So. The inverter consists of three sections all in one box.

1. Charge controller(s)

2. PEA et.al. input/output.

3. Inverter to convert DC charge controller output to 220/230v.

 

There are other ways of achieving the same with separate units which could cost a lot less.

 

 

[Fruit Trader]

1 hour ago, FlorC said:

Weird : To start the inverter normally. The recommended solar panel voltage is 300V-400V, the maximum is not more than 500V.

But : High efficiency pure sine wave inverter; Wide PV input range (90Vdc -500Vdc).

And: The power of the inverter must be at least three times the rated power of the induction loading device.

 

I  guess you are thinking why can't it start-up at minimum voltage. If not ignore my post.

 

At start-up, inverters will be looking for a voltage that allows it to function within a window between the min and max range. If the inverter detected minimum voltage at startup it would be pointless initialising because any load would likely trigger continuous low voltage restarts.

 

The induction load value is asking the installer to consider the high starting currents presented by some inductive loads.

[KhunLA]

@FlorC To add to the Muhendis' post above, they all have their own version of user friendly (hopefully) interface to control things.

 

Not knowing the others, ours seens pretty user friendly.  Touch screen and buttons selection on the inverter, and you can chose settings.  Use priority, and when and where the solar power or grid power goes.

 

Since wanting to be 'off grid', ours is set to use:

1st ... Solar

2nd ... ESS /battery

3rd ... Grid

If battery <35%, then grid kicks in, which will never happen

Unless 3 days of total crap weather.

 

Then we can choose if wanting more longevity out of batteries, a TOU (time of use) for the grid to kick in at anytime, by hours of the day, or simply when needed.   Same with export and % of what goes where & when.  We don't export at all.

 

Only thing that is connected directly to the grid, is the EV (car) wall charger, since it puts out 7.4kWh.  We rarely use that, and most charging is done with the granny/emergency charging cable that also came with the car.  Plugs into any outlet, and puts out 2.3kWh.  Use that when excess is available, and at least every other day, as don't let the car below 80% that often.

 

Deye doesn't have an app, that I know of, or use.  But there is a compatible app,

'Solarman Smart' that is wifi compatible, and will monitor the use, and record what is 

going on in real time and stores use history, and statistics (day, month, year, total), and most

anything needed.   Can not change inverter settings via that app.

 

Even when away from house in other provinces, can monitor the inverter.

Edited May 20 by KhunLA