5kW system with 10kW ESS question

[MJCM]

3 minutes ago, Crossy said:

I would however insist on half-cut (no, not 5 pints of Stella) panels, they are slightly more efficient and rather more reliable than regular panels.

Thx for this addition (edit)!!

[MJCM]

Just doing some searches on Lazada to compare prices.

 

Is this price to be good to be true?

 

Mono 450 Half 4937 THB

 

https://www.lazada.co.th/products/bluetech-solar-cell-monocrystalline-half-cell-solar-panel-450w-144cells-9bb-605w-120cells-10bb-i2038944613-s10489025325.html?

 

vs this

 

Poly 345 4064 THB

 

https://www.lazada.co.th/products/bluetech-mono-390w-144-cells-luma-mono144-half390w-390-monocrystalline-solar-panel-390w-9bb-30-i2403319563-s8219923535.html?

 

same seller!

 

For 900 THB more and 100 watts more then I rather go with the Mono or am I wrong and is there something I am missing?

 

Edit: The pictures for both say Mono description says Poly or Mono, so I guess same panel just less wattage??????????

[Crossy]

Second link also appears to be mono.

 

Global have poly 340W @ 3790 Baht.

 

Do your Baht-per-Watt sums and order the best bang for your buck.

 

I did buy a few panels from Lazada, one arrived broken and I spent ages unpacking the metres of bubble wrap.

 

Mostly I just ordered a bunch from Global for collection, paid online, they called when they were ready to pick up. In the back of the truck with cardboard in between (cardboard supplied by Global) for the 15 minute drive home. No unpacking and no waste bubble-wrap to dispose of.

 

 

[MJCM]

Looking at this Battery

 

https://www.lazada.co.th/products/lithium-phosphate-battery-power-wall-48v-200ah-15s-lifepo4-battery-10kwh-i2771668007-s10076827453.html

 

They write 48v 200ah = 10kWh.

 

Oke afaik the 10kWh is only available if you deplete the Battery to 0%, so if you go only to 50% this would only give you around 5 kWh. Correct?

 

So you are better (cheaper) buying 4x of these (put them in series) and buy a BMS and you have also a bit more storage

 

https://www.lazada.co.th/products/1-deep-cycle-gel-12v-250ah-i3332317210-s12367060291.html

 

Am I Correct?

 

Ps: Not talking about Lithium / Gel etc just about the absolute and usable storage!

[KhunLA]

42 minutes ago, MJCM said:

Looking at this Battery

 

https://www.lazada.co.th/products/lithium-phosphate-battery-power-wall-48v-200ah-15s-lifepo4-battery-10kwh-i2771668007-s10076827453.html

 

They write 48v 200ah = 10kWh.

 

Oke afaik the 10kWh is only available if you deplete the Battery to 0%, so if you go only to 50% this would only give you around 5 kWh. Correct?

 

So you are better (cheaper) buying 4x of these (put them in series) and buy a BMS and you have also a bit more storage

 

https://www.lazada.co.th/products/1-deep-cycle-gel-12v-250ah-i3332317210-s12367060291.html

 

Am I Correct?

 

Ps: Not talking about Lithium / Gel etc just about the absolute and usable storage!

Actually you would put them in parallel (48v), and yes, you don't want to drain them below 10% and keeping them about 20% on a regular basis is good.  Higher if you can manage it of course.

 

Charge up to 80% seems to be the optimal consistent level.  If knowing you'll need a bit more, then go full up.

 

I'm going to start with 10kWh, and that 60% (20-80%) should be more than enough to hold us overnight w/grid as back up.  1 AC (12btu inv) 2 small frigs, and TV / internet. If knowing we'll be going somewhere in the car, and may want to top that up, then go to 100 %.   All that depends what day (meter reading), and what's already (car) doesn't need much and how much the meter has gone backwards already.

 

Car would be plugged in during the day, and try keep above 40%, to 80% consistently for around town driving, < 20 kms day.  Easy  to top up the 20% if know we're going somewhere.

[MJCM]

Thx. We use approx 10-14 kWh a day, so I want (as end result) approx 6-10 kWh coming from solar and the rest from PEA. Reason being is that achieving all coming from Solar is a too big of an investment (for now) (Read: SWMBO)

 

But I guess my wife's the same as Crossy's wife, as soon as she sees the savings she wants more (electric Car for example. While we were in BKK she saw those cute pink ones (Not my cup of tea ???? ) which I believe are Chinese)

 

These ones

 

[MJCM]

11 minutes ago, KhunLA said:

Actually you would put them parallel (48v)

?? 4x12v Battery in Series would make 48v?

 

4x12v Battery in Parallel would still keep them at 12v?

 

https://battlebornbatteries.com/batteries-in-series-vs-parallel/

[KhunLA]

13 minutes ago, MJCM said:

?? 4x12v Battery in Series would make 48v?

 

4x12v Battery in Parallel would still keep them at 12v?

 

https://battlebornbatteries.com/batteries-in-series-vs-parallel/

oops ... my bad.  yea, the 12v's in series would be 48v.

 

Speed reading ... ???? Brain locked on 48v lithium.

[Khyron]

One way I have thought about an off-grid system, is to have the A/C connected to the solar, and everything else using PEA. This allows the most energy consuming device to be off the grid. When you have a brownout or blackout, have the whole house set up to be switched over to solar until such time the PEA is running again. When the mains drop out, you would have sensitive devices on a small individual UPS's, they would protect them from brownouts as well, which are much more damaging. Switching everything over to solar, would of course, allow life to go on. Switching could be automatic, or manually, using a large amperage industrial disconnect, relatively inexpensive and would last decades. I believe the above described system would allow solar to be used without interfering with the PEA, as it is totally independent. Getting deep into it, possibly programming a good PLC to detect a phase loss and energize a large contact, doing the switching automatically. I am open to suggestions, as I am a lowly Industrial mechanic and not an engineer. ????

 

 

[Encid]

3 hours ago, MJCM said:

While we were in BKK she saw those cute pink ones (Not my cup of tea ???? ) which I believe are Chinese)

They are indeed Chinese...

 

https://www.drive.com.au/news/ora-good-cat-everything-you-need-to-know/

[Encid]

3 hours ago, MJCM said:

Reason being is that achieving all coming from Solar is a too big of an investment (for now) (Read: SWMBO)

My wife is the opposite... she is looking forward to the "free electric" that a solar PV system plus ESS would provide.

Currently our biggest electricity consumers are the AC and the pool pumps (grid only electricity supply).

With "free electric" she is demanding that we install a pool with our new house build and 24/7 AC is a given. 

 

[MJCM]

33 minutes ago, Encid said:

My wife is the opposite... she is looking forward to the "free electric" that a solar PV system plus ESS would provide.

Currently our biggest electricity consumers are the AC and the pool pumps (grid only electricity supply).

With "free electric" she is demanding that we install a pool with our new house build and 24/7 AC is a given. 

 

55555555555

 

My wife has the following simple reasoning

 

- we pay let's say 2000 THB per month in electric. (so 24k per year)

- Why would we spend 300.000+ THB on Solar better uses for that money!

 

I tried to convince her that Electricity is only getting more expensive (see what will happen in Sept onward) etc etc but it's no use.

 

Solar is now a project that I have to do on my own and on the sly buy stuff (Panels GTI etc). After I have bought some stuff I will get "hell" (not really) from her, but then it's over and done with (ooh I can't take it back etc ???? )

 

She also has another reason why she is against Solar, it's because of the ordeal why we had to leave our OLD house (excessive NOISE and was a licensed place) and she is afraid that I will get solar in and we have leave again because the same happening here. In this she has a good point, but this discussion falls way out of the Title of this Topic ????

 

But I think if we do get Solar, first thing she wants is AC in the living room / More Pumps for her garden etc ????

[007 RED]

1 hour ago, Khyron said:

One way I have thought about an off-grid system, is to have the A/C connected to the solar, and everything else using PEA. This allows the most energy consuming device to be off the grid. When you have a brownout or blackout, have the whole house set up to be switched over to solar until such time the PEA is running again. When the mains drop out, you would have sensitive devices on a small individual UPS's, they would protect them from brownouts as well, which are much more damaging. Switching everything over to solar, would of course, allow life to go on. Switching could be automatic, or manually, using a large amperage industrial disconnect, relatively inexpensive and would last decades. I believe the above described system would allow solar to be used without interfering with the PEA, as it is totally independent. Getting deep into it, possibly programming a good PLC to detect a phase loss and energize a large contact, doing the switching automatically. I am open to suggestions, as I am a lowly Industrial mechanic and not an engineer. ????

 

 

Hello khyron and welcome to the Alternative and Renewable Energy Forum and hopefully when/if you eventually move to Thailand you will consider installing an alternative energy system.

 

Your idea of using solar panels to directly provide power to ‘drive’ an air conditioning system sounds plausible, but unfortunately in practice there a few minor (well major) problem actually, namely the sun, or the lack of it.

 

It would be wonderful if the moment that the sun appears above the horizon that the solar panels instantly generate their maximum power output.  If this was to happen, with sufficient solar panels and accompanying inverter you could enjoy AC from dawn to dusk, but sorry that just isn’t going to happen.

 

The problem is that from dawn to mid-day the panel’s output power gradually increasing until the point when the sun is perpendicularly above the panels at mid-day, at which point the panels should be producing their maximum output power.  Then from mid-day until dusk the panel’s output power is gradually decaying.  So unfortunately, such a system will only allow you to use the AC during the day.  What will you do in the evening or night?

 

In reality the other big problem are clouds which will considerably reduce the amount of sunlight hitting the panels and thus reducing the output power of the panels. 

 

At present here in Thailand we are in the monsoon season, so can potentially expect lots of clouds during the day and the occasional heavy downpour.  To illustrate the problems that I have explained above I’ve attached below an output graph from my small scale grid tied solar system taken a couple of days ago to show the havoc that clouds and rain can, and will, play with any solar system.

 

To overcome these problems the best solution would be to consider what is known as a Hybrid System, that is having the solar panels and possibly the grid power charging batteries which can then provide power when sun or grid are not available.  The only problem with this type of system is that it can be very, very, expensive.  I suggest that you take a look at @Crossy great introduction.

 

 

I hope all goes well with your plans to come to Thailand.

[Khyron]

Thanks for the detailed reply. The land for our house is being filled as I type, but it will be a few years to go before we build.

I forgot to mention, I would have a bevy of batteries to keep everything going but keeping them topped up on the grid is an idea I didn't think of. Crossy's drawing makes it all clear. 

Appreciate the welcome.

[Crossy]

One system it's worth looking at are the off-grid hybrids from Growatt, these will run in a "grid-boost" mode where the solar is topped up from the grid if necessary and they work with or without batteries.

 

https://www.lazada.co.th/products/growatt-spf-5000-es-hybrid-off-grid-5kw-inverter-wi-fi-parallel-max-6-30kw-i3783600307-s15346977294.html

 

One possible negative is that they cannot export, but of course this makes them "just another load" as far as PEA are concerned, no approvals required.

[BritManToo]

16 minutes ago, Crossy said:

One system it's worth looking at are the off-grid hybrids from Growatt, these will run in a "grid-boost" mode where the solar is topped up from the grid if necessary and they work with or without batteries.

 

https://www.lazada.co.th/products/growatt-spf-5000-es-hybrid-off-grid-5kw-inverter-wi-fi-parallel-max-6-30kw-i3783600307-s15346977294.html

 

One possible negative is that they cannot export, but of course this makes them "just another load" as far as PEA are concerned, no approvals required.

My VMII plus does exactly the same but only cost 13k5 (Inc WiFi) vs the growatt at 32k (WiFi extra) 

[Encid]

36 minutes ago, MJCM said:

we pay let's say 2000 THB per month in electric.

Currently we are paying between 6K and 9K per month (1260 kwh to 2150 kwh), so if we take an average of 7.5K that is 90K baht per year.

We do have a lot of family and friends visiting seasonally and that also drives up the consumption (additional AC usage and water heating for showers).

Also our current house is not at all energy efficient and that is one of the reasons why we want to sell and build new.

 

That's why I am following your topic with great interest... as I think my future needs will be similar... a 5kw system with a 10-15kw ESS.

 

Not wanting to ambush or hijack your topic but I would appreciate any replies/suggestions.

[Crossy]

3 minutes ago, BritManToo said:

My VMII plus does exactly the same but only cost 13k5 (Inc WiFi) vs the growatt at 32k (WiFi extra) 

 

U got a link? Does it actually do "grid boost" rather than just going into bypass mode?

[MJCM]

6 minutes ago, Encid said:

Not wanting to ambush or hijack your topic but I would appreciate any replies/suggestions.

No problem, my (our) Solar Install is in the Pre-Pre Alpha stages before it reaches Beta it will be next year or so I guess.

[BritManToo]

7 minutes ago, Crossy said:

 

U got a link? Does it actually do "grid boost" rather than just going into bypass mode?

Yes, it adds pv and battery, or pv and grid, you get to nominate source priority. 

It's sold under many labels. 

https://s.lazada.co.th/s.SWHcj

 

Cheaper to buy direct from China. 

[MJCM]

3 minutes ago, BritManToo said:

Yes, it adds pv and battery, or pv and grid, you get to nominate source priority. 

It's sold under many labels. 

https://s.lazada.co.th/s.SWHcj

 

Cheaper to buy direct from China. 

Correct if I say:

 

PV to Battery and if not enough in Battery then not getting from the Gird (if Battery has highest prio)?

 

Or totally wrong?

[Encid]

6 minutes ago, MJCM said:

No problem, my (our) Solar Install is in the Pre-Pre Alpha stages before it reaches Beta it will be next year or so I guess.

Same here 

[Bandersnatch]

16 hours ago, Crossy said:

One system it's worth looking at are the off-grid hybrids from Growatt, these will run in a "grid-boost" mode where the solar is topped up from the grid if necessary and they work with or without batteries.

 

https://www.lazada.co.th/products/growatt-spf-5000-es-hybrid-off-grid-5kw-inverter-wi-fi-parallel-max-6-30kw-i3783600307-s15346977294.html

 

One possible negative is that they cannot export, but of course this makes them "just another load" as far as PEA are concerned, no approvals required.

I have three Growatt SPF 5000 ES and I can recommend them. The app is great. My 20kW of PV means that I was never going to be allowed to export. My system powers my house and EV with most months no power being used from PEA. In the picture below you can see I have a 4th inverter which is connected to my original Deep Cycle Gel system. I have an ATS which allows me to use my old solar system as “Grid” (Power sources in order: Solar; Battery; Utility) and then switch over to PEA.

 

 

[MJCM]

Found a Handy Solar Calc.

 

You input your Power Usages and Battery Voltage etc and it will give you Solar Panels Watts and Solar Panels kWh

 

https://www.bimblesolar.com/solarcalc

[KhunLA]

35 minutes ago, MJCM said:

Found a Handy Solar Calc.

 

You input your Power Usages and Battery Voltage etc and it will give you Solar Panels Watts and Solar Panels kWh

 

https://www.bimblesolar.com/solarcalc

I just went by my PEA usage from rental, poorly constructed/insulated (none), though townhouse, so half walls exposed to sun.

 

1 AC (sm) on all day usually, and we averaged 600-700 kWh a month.

 

5kW system would actually provide enough, as they average about 20kwh a day produced.

 

Going with 8kW inverter, should average 35 a day.  Can never have too much juice, especially with EV (car) coming.

 

May have miscalculated usage for new house.  Been here 6 days, and only use 60 PEA unit, so 10 a day.  That's with 1 AC (12btu inv) on all day.  Worker using welder (carport), still a work in progress.  

 

Been very sunny everyday, so construction material, insulation, and roof shading has made a huge difference in usage.

 

No curtains on the main windows exposed, mostly the bedroom (sliding door size) with AC, so once those up, even less need to cool off the room.

 

Solar system should be installed by mid month, August.

[MJCM]

1 hour ago, KhunLA said:

5kW system would actually provide enough, as they average about 20kwh a day produced.

 

Going with 8kW inverter, should average 35 a day.  Can never have too much juice, especially with EV (car) coming.

So I am correct in thinking you are going with approx 10+ of your Mono Panels (you linked to in a previous post)?

 

Which Inverter are you going with?

[KhunLA]

2 hours ago, MJCM said:

So I am correct in thinking you are going with approx 10+ of your Mono Panels (you linked to in a previous post)?

 

Which Inverter are you going with?

18 panels & Deye hybrid inverter

 

1.  PANELS  540 WP SUNTECH SOLAR PANELS X 18 

https://www.suntech-power.com/products/ultra-v-series/#section-60e07a62

 

2. DEYE 8 KWS HYBRID SINGLE PHASE INVERTER

https://www.deyeinverter.com/product/hybrid-inverter-1/hybrid-inverter-sun5-6ksg01lp1us-sun7-6-8ksg01lp1us-eu.html

 

[MJCM]

37 minutes ago, KhunLA said:

18 panels & Deye hybrid inverter

Wow you are taking it right up to the limit! ????

 

[KhunLA]

24 minutes ago, MJCM said:

Wow you are taking it right up to the limit! ????

 

Yea, I told the installer, the max of what the inverter can handle, that's how many I want.  His original was only 2 shy of 18 anyway.

 

Figure the more panels, on cra ppy days, will still get 20kw a day, and if battery low, 6 will be on the E roof and start producing at sunrise.  The 3 roofs have the slightest pitch, so probably spread out equally 6-6-6 / E S W.   The roof plan was designed with solar in mind.  None shaded at all.  Should get optimal performance from any system.

 

 

[MJCM]

Anyone any experience with this Inverter

 

https://www.lazada.co.th/products/powland-55kw90a-mppt-48v-ct-ve-ii-55kw-wifi-i3800504715-s14463629775.html

 

5.5kW+WiFI = 25.940 THB. Seems cheap!

 

 

Quote

 

✦Model：VE-II-5.5KW-Wifi

✦5500W rated output power

✦MPPT 90A solar charging

✦Max PV input voltage：500VDC; Max PV input power：5500W 

✦Battery type：48V lead-acid battery or lithium battery

✦Output voltage：230V pure sine wave 

✦Output frequency：50Hz or 60Hz

✦Surge power：11000VA