5kW system with 10kW ESS question

[MJCM]

Hi,

 

it's me again ????

 

So I am thinking of getting a 5kW system with a 10kW ESS. (Tweaking the email for the quote request all the time )

 

Now if the installer agrees with the location of the Inverter and the ESS I was just thinking out loud because I have lots of space there

 

Now my question:

 

What if I went for a 10kW ESS and an additional 5kW ESS (so 2 ESS) and limit the Battery Discharge on both of them thus giving them a longer lifespan. (Both Batteries will last longer is the idea). Or am I talking BS / Stupid here and does this (with this combination) NOT work???

 

 

[mistral53]

Doesn't compute for me at all - the 10 Kw ESS is probably 4 times as expensive as the 5 Kw solar installation........what do you try to achieve?

[Crossy]

For those who don't know - ESS = Energy Storage System (batteries).

 

A 5kWP solar system will generate 15-20 kWh on a decent day.

 

So a 10kWh ESS will be charged by lunch time assuming you don't have a massive daytime load. If that's enough juice to keep you running over night then all is good.

 

Adding another 5kWh ESS certainly wouldn't do any harm and would give you a bit more autonomy on the UPS output of your inverter.

 

In reality I don't really see much of an advantage assuming you have a lithium ESS of course.

[MJCM]

Just now, mistral53 said:

Doesn't compute for me at all - the 10 Kw ESS is probably 4 times as expensive as the 5 Kw solar installation........what do you try to achieve?

Try to reduce our PEA solar bill and I already explained in another thread that Id rather invest the money in Solar then getting 0,5% interest!  (I will make more money each year from the Solar then the Bank is giving me (I think that I already break even (Bank Interest vs Solar Saving) after 2 months!!

 

 

[MJCM]

1 minute ago, Crossy said:

In reality I don't really see much of an advantage assuming you have a lithium ESS of course.

Yes LifePo4!!

 

My thinking was, limiting the DOD that it will make the Batteries last longer.

 

Batteries are the most expensive in the whole quote and I just want to have them last longer

[MJCM]

7 minutes ago, Crossy said:

So a 10kWh ESS will be charged by lunch time assuming you don't have a massive daytime load. If that's enough juice to keep you running over night then all is good.

You are completely right about this, but my wife is getting slowly on board on this solar plan, and she already has said that she wants an Aircon in the Living Room when we get the Solar  (And she already asked for a 2HP pump for a Garden (up from 1HP) ????

 

So our usage will definitely go UP when we get the Solar

[Crossy]

With a new LiFePO4 pack you should be good for >3,000 cycles and still have >80% of initial capacity. So heading for 10 years before even thinking about replacement.

 

The technology can only get better and almost certainly cheaper, so maybe waiting for the second ESS might be an idea. 

 

If you get things wired for 2 x ESS and 2 x hybrid inverters then an upgrade would simply involve plugging stuff in and adding more panels.

[MJCM]

Thanks @Crossy

 

Real good points you make.

 

I will wait and go for the initial 5kW System and only 1 ESS (10 kW) (but have it so I can upgrade in the Future if Needed)

 

Appreciated!!!

[MJCM]

Found these ESS (on a thread here). Any other ones to consider??

 

https://th.aliexpress.com/item/4001183652566.html

https://www.seplos.com/sale-13059885-pusung-rack-mount-51-2v-power-5kw-energy-lifepo4-100ah-home-storage-backup-48v-solar-system-lithium-.html

 

That's 75k (excl Shipping) for one so because I need (read WANT ????) 2 that's 150k already spend (another one can be easily added)

 

Any other ones to consider??

[Bandersnatch]

DOD will effect the life of a lithium battery (See Table below from Battery university) 

 

 

[MJCM]

Thx @Bandersnatch really surprised that at 80% (for liPo4) it's only +/- 900. That is only approx 2 years.

 

For the Pusung Battery it says:

 

Cycle life 80% DOD and 25°C 2500 Times

 

How come the big difference??

[Bandersnatch]

22 minutes ago, MJCM said:

Thx @Bandersnatch really surprised that at 80% (for liPo4) it's only +/- 900. That is only approx 2 years.

 

For the Pusung Battery it says:

 

Cycle life 80% DOD and 25°C 2500 Times

 

How come the big difference??

I agree it does seem very short. My LiFePO batteries have a much longer claimed life. I do not know what batteries were tested in the study or even when the study was done, but my take away is DOD does have effect on cycle life, so I am planning to over spec my storage accordingly.

 

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

[MJCM]

Thx for that link but reading it comes at somewhat of a shock

 

Quote

 

Lithium-ion suffers from stress when exposed to heat, so does keeping a cell at a high charge voltage. A battery dwelling above 30°C (86°F) is considered elevated temperature and for most Li-ion a voltage above 4.10V/cell is deemed as high voltage. Exposing the battery to high temperature and dwelling in a full state-of-charge for an extended time can be more stressful than cycling.

 

So I need to put an Aircon in the storage where I think I will place the Battery lots of airflow there, because temperatures tend to get high there. So I need a re-think of where to place them!

[Bandersnatch]

Just now, MJCM said:

So I need to put an Aircon in the storage where I think I will place the Battery lots of airflow there, because temperatures tend to get high there. So I need a re-think of where to place them!

 

My mechanical room is insulated  - AAC blocks, white steel roof with foil and foam insulation with a 50 inch ceiling fan.

 

I don't plan to use aircon as I want to keep the room well ventilated, but I am planning to revisit geothermal.

 

 

[MJCM]

2 hours ago, MJCM said:

Thx for that link but reading it comes at somewhat of a shock

 

So I need to put an Aircon in the storage where I think I will place the Battery lots of airflow there, because temperatures tend to get high there. So I need a re-think of where to place them!

Already found the solution. In the place where I want to store the Inverter(s) and ESS, I have lots of space.

 

Our builder come on another matter and I discussed it with him, he can make a room 2mx2m in the proposed area with 15cm AAC blocks and put insulation on top. And then I will put in a portable aircon (9000 BTU (which is IMHO overkill) for example: https://www.lazada.co.th/products/new-9000-btu-tac-09cpars-portable-air-conditioner-touch-control-led-displaystrong-cooling-dual-fan-motor-quiet-operating-i1703310735-s4822530799.html and that would solve my problem. And because I am then on Solar it won't cost me anything to run this aircon 24/7)

 

Any thoughts??

[tjo o tjim]

21 hours ago, MJCM said:

Thx @Bandersnatch really surprised that at 80% (for liPo4) it's only +/- 900. That is only approx 2 years.

 

For the Pusung Battery it says:

 

Cycle life 80% DOD and 25°C 2500 Times

 

How come the big difference??

I am fairly certain those are older numbers— maybe even 3-4 years.  Performance has improved dramatically.

[BritManToo]

This 12KWHr (48V 260AH) LiFePO4 battery claims 5,000 cycles at -10c to 45c

 

Not bad for 50Kbht.

If a little heavy at 108Kg.

 

https://shopee.co.th/BYD-LiFePO4-แบตเตอรี่ลิเทียมฟอสเฟส-ยี่ห้อ-BYD-ขนาด-1P16S-48v-260Ah-เป็นโมดูลสำเร็จรูป-ใส่JKBMSมีActive-2A-ใช้งานได้ทันที-i.35505682.10250909131

[Encid]

So @MJCM what did you end up buying?

 

I have been scouring this forum to learn as much as I can about Solar systems and what would work best for me when our new house is finally built.

 

One question for all you guys who live up-country... how do your systems handle the frequent voltage fluctuations and outages (and startups) from the PEA grid?

If you have an on-grid hybrid system that only imports power from the grid during inclement weather conditions, do your inverters/batteries deliver a constant 220v AC to your home?

 

I know of one guy in Surin who has hooked up dedicated UPS's to all his vital home electronic gear because of the brownouts, blackouts, and surges. He too is thinking about installing a solar power system.

 

Would having an on-grid hybrid system eliminate the need for individual UPS's?

[Bandersnatch]

3 hours ago, Encid said:

I know of one guy in Surin who has hooked up dedicated UPS's to all his vital home electronic gear because of the brownouts, blackouts, and surges. He too is thinking about installing a solar power system.

 

My house is in Surin if that's where you're based. Had quite a few visitors over the years to look at my setup - you are welcome if you give us a bit of notice

 

EcoHouseThailand.com

 

 

[Encid]

23 minutes ago, Bandersnatch said:

 

My house is in Surin if that's where you're based. Had quite a few visitors over the years to look at my setup - you are welcome if you give us a bit of notice

 

EcoHouseThailand.com

 

 

Thank you very much for your offer!

I am currently based in Najomtien, Chonburi, but am planning to build near Phon which is about 1 hour's drive south of Khon Kaen.

Technically it is in Korat, but Khon Khaen is closer.

I will touch base with you the next time I plan to travel up there.

What flavoured beer do you prefer? 

[Bandersnatch]

4 minutes ago, Encid said:

What flavoured beer do you prefer? 

Don’t drink alcohol, happy drinking soda. Can drink as many as you like when it’s hot ???? 

[MJCM]

4 hours ago, Encid said:

So @MJCM what did you end up buying?

NOTHING _yet!

 

My wife is the main disagreement here. She is absolutely not convinced in the USE of Solar.

 

I have spend many hours trying to convince her but the numbers don't add up for her.

 

A friend once told me what is more important to you, being right or being married

 

I chose to be married!!

 

Ps: I still do have hope that my wife yields one day

PsPs: Another thing is I had also issues with (maybe wanting too much) and installers/suppliers not able to comply (but that is another story (maybe it was out of their comfort zone))

[MJCM]

5 hours ago, Encid said:

I know of one guy in Surin who has hooked up dedicated UPS's to all his vital home electronic gear because of the brownouts, blackouts, and surges. He too is thinking about installing a solar power system.

I am not in Surin (but not that far away) and all of my PC's / TV's / Media Centers / Fridges have ALL individual UPS's.

 

We have MANY of those brown/black outs that only last 1 maybe 2 seconds max and that  (AFAIK ( @Crossy (care to comment)) could be disastrous for your equipment.

 

So the power goes off and most of the time it immediately comes back one.

 

Afaik these surges are not good for your equipment and that is why I have those UPS'sessss ????

 

 

[Crossy]

19 minutes ago, MJCM said:

My wife is the main disagreement here. She is absolutely not convinced in the USE of Solar.

 

I have exactly the opposite "problem".

 

Madam was a bit sceptical to start with but having seen real savings on our power consumption / bill with our initial baby system she was sold.

 

So now we have >10kWP on the car port, not quite zero grid energy but 100 kWh per month from PEA vs actually using 6-7 times that.

 

Madam is now pressing for an EV and the extra solar to support it, Billy Muggins will (of course) be expected to finance same. To be honest I don't really mind but that's not the point.

 

 

[MJCM]

2 minutes ago, Crossy said:

I have exactly the opposite "problem".

 

Yeah I can remember, she was not convinced at 1st but now wanting more and more.

 

Mine is still the opposite and she keeps staying there ????

 

Edit: Even me upgrading the car to a newer one, she is totally against it, she just says this car is good enough for us!!

[Encid]

27 minutes ago, MJCM said:

I am not in Surin (but not that far away) and all of my PC's / TV's / Media Centers / Fridges have ALL individual UPS's.

 

We have MANY of those brown/black outs that only last 1 maybe 2 seconds max and that  (AFAIK ( @Crossy (care to comment)) could be disastrous for your equipment.

 

So the power goes off and most of the time it immediately comes back one.

 

Afaik these surges are not good for your equipment and that is why I have those UPS'sessss ????

 

 

 

5 hours ago, Encid said:

Would having an on-grid hybrid system eliminate the need for individual UPS's?

 

So @Crossy, what do you think/recommend?

[Bandersnatch]

Most solar inverters are pure sine wave and produce a much more stable voltage than the grid. 
 

having battery backup means I have no extra ups in the house but a smaller battery will mean that you will be back on the grid when they run out of power, but you might be sleeping by then. 

 

some people use a small solar battery just as a UPS so it powers only a few circuits in the house during a power cut.

[Khaoyaiman]

I'm also planning on installing a Hybris 5Kw single phase system with 10KWh lifepo4 battery storage. I've been asking for prices from several solar companies. Most of them start off at THB160-180k for an on grid system, then when I ask for batteries, the price goes up from THB250k to THB350k. I understand there are a lot of different batteries out there, but most that I've seen are between THB40k and THB70K so I'm wondering why the massive increase in price just to supply and wire in some batteries? Apologies now for my lack of solar knowledge!

[KhunLA]

7 minutes ago, Khaoyaiman said:

I'm also planning on installing a Hybris 5Kw single phase system with 10KWh lifepo4 battery storage. I've been asking for prices from several solar companies. Most of them start off at THB160-180k for an on grid system, then when I ask for batteries, the price goes up from THB250k to THB350k. I understand there are a lot of different batteries out there, but most that I've seen are between THB40k and THB70K so I'm wondering why the massive increase in price just to supply and wire in some batteries? Apologies now for my lack of solar knowledge!

On grid vs hybrid inverter, bit more expensive along possibly needing a 'controller'.

 

Also new at this, and been researching for a while.  Sure someone will chime in with better, actual experienced answer.

[BritManToo]

1 hour ago, Khaoyaiman said:

I'm also planning on installing a Hybris 5Kw single phase system with 10KWh lifepo4 battery storage. I've been asking for prices from several solar companies. Most of them start off at THB160-180k for an on grid system, then when I ask for batteries, the price goes up from THB250k to THB350k. I understand there are a lot of different batteries out there, but most that I've seen are between THB40k and THB70K so I'm wondering why the massive increase in price just to supply and wire in some batteries? Apologies now for my lack of solar knowledge!

Batteries are expensive, expect to pay at least 50,000bht for a 48V 200AH battery.

These are about the best I've seen available in Thailand at the moment.