Solar - 8kW Hybrid Inverter w/10kWh (upgraded to 20kWh in Sept. 2022) ESS/battery (not DIY)

[MJCM]

14 hours ago, KhunLA said:

Here's the not so 'fine print' ...

"In the first scenario, the FT rate for the January-April period will be 224.98 satang per unit, so that the Electricity Generating Authority of Thailand (EGAT) will be able to recover its losses, incurred from its subsidy of electricity price, amounting to about 81 billion baht, in one year. This means the price of electricity will be increased to 6.03 baht per unit.

 

In the second scenario, the FT will be 191.64 satang, so EGAT will be able to recover its losses, incurred from its subsidy of electricity price, in two years. This will bring the price of electricity rate to 5.70 baht per unit.

 

Under the third scenario, the price of electricity will be 5.37 baht per unit."

https://www.thaipbsworld.com/service-fees-for-household-and-small-business-electricity-use-to-be-cut-jan-apr/

I made a small Spreadsheet with the possible effects of the increased Ft (Only used the Highest Ft increase of 224.98 satang per unit)

 

What you see is:

 

1 x 299 Units with the Current max Discount

1 x 299 Units with the new Ft of 224.98 satang per unit

1 x 500 units with the Current Ft charge (93.43 satang per unit)

1 x 500 Units with the new Ft of 224.98 satang per unit.

 

I hope you are prepared for this. (please do excuse Arithmetic errors )

 

[motdaeng]

4 hours ago, Crossy said:

The alternative is to go legal. Doing it this way will at least double the cost of your system and half the rate you are paid for the energy you export. You need to use approved equipment and use an approved installer, there's then a stack of paperwork and a wait (often a very long wait) to get your export meter installed. 

what are the reasons for double the cost?

 

would it be possible to buy panels, mounting systems, cables, inverters,

breakers, etc. yourself and have them installed by a company?

(like building a house and you only pay the labour costs)

 

does it really have  to be an approved installer? is there no other way?

the costs for the permit (paperwork etc) itself can't be that high ... or am i completely wrong?

 

the alternative with batteries is not cheap either ... especially when you consider

the lifespan of batteries! 

[MJCM]

8 minutes ago, motdaeng said:

what are the reasons for double the cost?

I think because you need an approved installer, approved Inverter and don't forget the Installer need to submit up to date paperwork. Even someone as experienced as @Crossy is not allowed to do the install himself if he wants to go the PEA official route.

 

8 minutes ago, motdaeng said:

would it be possible to buy panels, mounting systems, cables, inverters,

breakers, etc. yourself and have them installed by a company?

(like building a house and you only pay the labour costs)

I guess so, but the installers will not be happy when you do this and it could lead (worse case scenario of course) that you have to buy everything again and then from them.

 

But as always YMMV

 

  

8 minutes ago, motdaeng said:

the alternative with batteries is not cheap either ... especially when you consider

the lifespan of batteries! 

AFAIK, If you treat your Batteries (LFP4) nicely for example like charge them only 90-95% max and then only discharge them 40-45% (so treat them nice and gently) then you could increase the lifetime substantially. Someone more experienced in this Matter will of course correct me when I am wrong about this,

 

[Crossy]

What he said ^^^.

 

The solar installers know they have you over a barrel so they can bump up their costs, expect equipment and accessories to be 40 - 45% of the total installed cost. And yes, they do have to be actual registered contractors, you can't DIY "to code" and get approval, I asked! 

 

LiFePO4 batteries are significantly more long-lived than lead-acid and keeping them in the 20-80% charge range should put them well into the 8,000 cycles (22 years' worth) bracket before they lose a significant amount of capacity.

 

[indyo]

2 hours ago, Crossy said:

What he said ^^^.

 

The solar installers know they have you over a barrel so they can bump up their costs, expect equipment and accessories to be 40 - 45% of the total installed cost. And yes, they do have to be actual registered contractors, you can't DIY "to code" and get approval, I asked! 

 

LiFePO4 batteries are significantly more long-lived than lead-acid and keeping them in the 20-80% charge range should put them well into the 8,000 cycles (22 years' worth) bracket before they lose a significant amount of capacity.

 

Li-ion batteries are too dangerous I don't want a bomb near my home so LiLiFePO4 batteries is the only go for me as I can buy the single cells but I have to import them. is there any trusted LiFePO4 cells or batteries seller here?

my only concern about the LiFePO4 batteries is the working environment temperature that is too high here.

[Crossy]

24 minutes ago, indyo said:

Li-ion batteries are too dangerous I don't want a bomb near my home so LiLiFePO4 batteries is the only go for me as I can buy the single cells but I have to import them. is there any trusted LiFePO4 cells or batteries seller here?

my only concern about the LiFePO4 batteries is the working environment temperature that is too high here.

 

I agree with your sentiments on Li-ion although if they are in a fireproof home away from your house and vehicles there's not really that much risk.

 

Buying cells on-line is a nightmare, there are far too many sellers with "new" cells that are really used, at least we knew that our cells were used and sold as such. I've also bought 32650 cells from one seller and had good experiences only to buy some more from the same seller and got junk.

 

There are known good sellers on AliBaba / AliExpress but for best results you need to look at the dedicated solar energy forums, we really have too small a footprint here to maintain accurate and up to the second data.

 

Our cells live in a well shaded home, we don't push them really hard so battery temperatures rarely climb above ambient.

[KhunLA]

2 hours ago, Crossy said:

Our cells live in a well shaded home, we don't push them really hard so battery temperatures rarely climb above ambient.

Ours are in the foyer, and live in AC.  I'm comfy, they're comfy.  System being a bit larger than needed, so neither inverter nor batteries should be feeling any stress ????

[Muhendis]

7 hours ago, Crossy said:

LiFePO4 batteries are significantly more long-lived than lead-acid and keeping them in the 20-80% charge range should put them well into the 8,000 cycles (22 years' worth) bracket before they lose a significant amount of capacity.

Yup.

And in addition to that LiFePO4's are quite content to be part charged on cloudy days whereas lead acid will suffer from sulfation which will accumulate over time and kill the battery sooner rather than later. Also best working temperature of lead acid is 25ºC whereas LiFePO4 is 30ºC which is normal for Thailand.

[Muhendis]

5 hours ago, indyo said:

my only concern about the LiFePO4 batteries is the working environment temperature that is too high here.

LiFePO4's are reasonably happy at 30ºC. They will loose capacity a bit quicker above 35ºC but, unlike lead acid temperature is not so much of a big deal for them.

Fears of the fire/bomb risk:

Lithium ion batteries will go into thermal runaway at, if I remember rightly, 356ºC whereas LiFePO4's are good for 460ºC until runaway starts. These are internal temperatures.

A good BMS will ensure this can never be due to over charging or discharging too fast.

Keeping them away from a heat source is also a good idea.

[Muhendis]

23 hours ago, Crossy said:

LiFePO4 batteries are significantly more long-lived than lead-acid and keeping them in the 20-80% charge range should put them well into the 8,000 cycles (22 years' worth) bracket before they lose a significant amount of capacity.

It is also worth mentioning that the 20% to 80% charge range is a reduction in the battery effective capacity so if you're going to reduce the charge/discharge levels you will need to increase the quantity of cells to maintain the overall capacity.

For example:

100Ahr battery @ 20 - 80% = 60Ahr usable capacity

167Ahr battery @ 20 - 80% = 100.2Ahr usable capacity

So if it is calculated that 100Ahr battery is required for an installation then the actual size to fit would be 167Ahr at 20 - 80% 

[Crossy]

21 hours ago, indyo said:

... is there any trusted LiFePO4 cells or batteries seller here?

 

Moving on from my earlier comments Shenzen Luyuan are very well regarded on other solar forums and they definitely supply new cells.

https://szluyuan.en.alibaba.com/

I've not bought from them personally, but I've not heard any negative reports.

 

[motdaeng]

if i am not mistaken, someone asked on the forum about the tesla powerwall ...

price starts at 599'000 thb (14 kwh) !!!!!!!!

 

https://www.solar-d.co.th/en/

 

 

[Crossy]

1 hour ago, motdaeng said:

if i am not mistaken, someone asked on the forum about the tesla powerwall ...

price starts at 599'000 thb (14 kwh) !!!!!!!!

 

https://www.solar-d.co.th/en/

 

Ouch!

 

I can build a 280Ah 48V (13.4kWh) pack using grade A cells and a DIY kit from Seplos for about 2,500USD (95k Baht) and keep the other half million in the bank ???? 

 

OK the Powerwall does include a 10kW inverter and the management hardware, so add another 50k ???? 

 

[KhunLA]

1 hour ago, motdaeng said:

if i am not mistaken, someone asked on the forum about the tesla powerwall ...

price starts at 599'000 thb (14 kwh) !!!!!!!!

 

https://www.solar-d.co.th/en/

 

 

Whoa ...

... that's 154k over our whole system's cost, installed, with 18/540w panels.  The power wall also shy a few kW of ESS, 20 vs 13.5.

[MJCM]

47 minutes ago, Crossy said:

I can build a 280Ah 48V (13.4kWh) pack using grade A cells and a DIY kit from Seplos for about 2,500USD (95k Baht)

Can I put an order in? ????

[Crossy]

24 minutes ago, MJCM said:

Can I put an order in? ????

 

Of course;-

 

Order your cells here 

https://www.alibaba.com/product-detail/Luyuan-8pcs-280AH-LiFePO4-LFP-3_1600066769898.html?spm=a2700.shop_index.89.1.7db6273e83n0Uy

You need to order 2 (16 cells).

 

And the DIY kit here

https://www.seplos.com/sale-21924968-mason-diy-unit-suitable-eve-280ah-cell-box-stack-type-without-cells.html

 

And make this ???? 

 

[BritManToo]

1 hour ago, Crossy said:

 

Ouch!

 

I can build a 280Ah 48V (13.4kWh) pack using grade A cells and a DIY kit from Seplos for about 2,500USD (95k Baht) and keep the other half million in the bank ???? 

 

OK the Powerwall does include a 10kW inverter and the management hardware, so add another 50k ???? 

 

Or you could buy one ready made for 56Kbht

https://www.lazada.co.th/products/nmc-48v-246ah-125742kw-smart-bms-i3540994257-s13213589046.html

 

OK, so it's Lithium, but it's also half the price.

16kwhr for 66Kbht

https://www.lazada.co.th/products/48v-300ah-smart-bms-150300a-1585kw-i2554477759-s9087152255.html

[Crossy]

11 minutes ago, BritManToo said:

Or you could buy one ready made for 56Kbht

https://www.lazada.co.th/products/nmc-48v-246ah-125742kw-smart-bms-i3540994257-s13213589046.html

 

OK, so it's Lithium, but it's also half the price.

16kwhr or 66Kbht

https://www.lazada.co.th/products/48v-300ah-smart-bms-150300a-1585kw-i2554477759-s9087152255.html

 

Yeah, definitely tempting despite being Li-ion.

 

[JBChiangRai]

On 12/2/2022 at 10:05 AM, Crossy said:

What he said ^^^.

 

The solar installers know they have you over a barrel so they can bump up their costs, expect equipment and accessories to be 40 - 45% of the total installed cost. And yes, they do have to be actual registered contractors, you can't DIY "to code" and get approval, I asked! 

 

LiFePO4 batteries are significantly more long-lived than lead-acid and keeping them in the 20-80% charge range should put them well into the 8,000 cycles (22 years' worth) bracket before they lose a significant amount of capacity.

 

If you want the approved feed in tariff, then buy the smallest system you can from an approved installer, and when it's finished bump it up with another parallel system yourself.

[MJCM]

1 hour ago, Crossy said:

 

Of course;-

 

Order your cells here 

https://www.alibaba.com/product-detail/Luyuan-8pcs-280AH-LiFePO4-LFP-3_1600066769898.html?spm=a2700.shop_index.89.1.7db6273e83n0Uy

You need to order 2 (16 cells).

 

And the DIY kit here

https://www.seplos.com/sale-21924968-mason-diy-unit-suitable-eve-280ah-cell-box-stack-type-without-cells.html

 

And make this ???? 

 

 

When I do that I think I will be pestering someone so much that I am the first person who is on there blocklist

[Crossy]

8 minutes ago, JBChiangRai said:

If you want the approved feed in tariff, then buy the smallest system you can from an approved installer, and when it's finished bump it up with another parallel system yourself.

 

Thing is, what happens when your "3kW" system starts blasting 9kW into the grid?

 

The authorities here are not totally stupid, despite appearances sometimes.

[MJCM]

19 minutes ago, Crossy said:

 

Thing is, what happens when your "3kW" system starts blasting 9kW into the grid?

 

The authorities here are not totally stupid, despite appearances sometimes.

So what you are saying is, when you have a 3kW system they expect something like (example) 40 Units that they have to pay for at the end of the month, but when you then install 6kW system beside it and you feed in 90 units (again example) that they could come and visit?

 

I like the idea, but after the @Thaifish story I am (personally) staying far away from Official Net Metering.

 

For us it's either

 

A- Being "Illegal" and Exporting

B- If a NON Export Meter is installed, a system with ESS and a fallback to the grid only in case our ESS runs "dry"

[Crossy]

1 minute ago, MJCM said:

So what you are saying is, when you have a 3kW system they expect something like (example) 40 Units that they have to pay for at the end of the month, but when you then install 6kW system beside it and you feed in 90 units (again example) that they could come and visit?

 

It's pure speculation on my part, but I would suspect anything much over 400 units exported from a 3kW system in a month (that would mean no local usage) MIGHT trigger an alarm somewhere.

 

Like you we'll stick with the "unofficial" net metering (and get 1:1 $$$) and expand our storage should an electronic/no-reverse meter come a calling.

 

[Encid]

36 minutes ago, Crossy said:

It's pure speculation on my part, but I would suspect anything much over 400 units exported from a 3kW system in a month (that would mean no local usage) MIGHT trigger an alarm somewhere.

Don't forget those PEA "spy drones" that are attracted to meters spinning backwards... 

[motdaeng]

an other point to consider:

if you would legally feed into the grid, then you won't spend

big money for an EES! (or would you?)

BUT if there is a power failure at night, you will not have any

electricity, because you don't have an EES ....

that makes also not so much sense, doesn' it?

 

[Encid]

4 minutes ago, motdaeng said:

if you would legally feed into the grid, then you won't spend

big money for an EES! (or would you?)

Many time up-country the PEA turns off the domestic grid when there are thunderstorms around.

Unless you have your own ESS or a backup generator you would be without power.

[Crossy]

A lot depends upon your usage patterns and the propensity for the grid to go off.

 

We have about 10kWh of ESS which I keep above 60% full in case the juice goes off, there's an auto-start genset if the ESS isn't sufficient.

 

[KhunLA]

35 minutes ago, Encid said:

Many time up-country the PEA turns off the domestic grid when there are thunderstorms around.

Unless you have your own ESS or a backup generator you would be without power.

When we lived in Udon Thani area, they consistently had rolling brown outs, when downtown needed juice.   The outer villages were turned off.

 

Seems my wife was the only person that called in from both villages we lived in, as they turn it back on within 5 minutes of her calling.   Can imagine the rep thinking ... 

... "Oh Krap ... it's her again" ????

 

 

[MJCM]

10 minutes ago, motdaeng said:

an other point to consider:

if you would legally feed into the grid, then you won't spend

big money for an EES! (or would you?)

BUT if there is a power failure at night, you will not have any

electricity, because you don't have an EES ....

that makes also not so much sense, doesn' it?

 

It makes total sense, I am struggling with this dilemma as well, but Yes I would spend money on the ESS why

 

I don't want to be at the mercy of the PEA because who knows one day they say people with Net metering you only get xx satang instead of (currently 2 THB) for every unit you push into the Net. (don't forget they determine the price)

 

But even for us (modest users @ 8-10 Units per day) going totally free from PEA would mean an investment of 3-600k THB, which I would do but SWMBO definitely NOT.

 

I would love to have all our lights on (and aircon working) when there is a power failure and everywhere else is in darkness (how cruel that may sound).

[MJCM]

2 minutes ago, KhunLA said:

Seems my wife was the only person that called in from both villages we lived in, as they turn it back on within 5 minutes of her calling.   Can imagine the rep thinking ... 

... "Oh Krap ... it's her again" ????

In our village it's still my wife (her name the PEA app is registered to) but I am doing the reporting (in English ) (something like: Again no electricity in the whole of the neighbourhood)