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

[KhunLA]

Solar production past 3 days has been just OK, and looks like the next week, probably 5 to 7 of the next 10 days, is going to be the same.

 

 

Good .. not brutally sunny & hot, and no 'feels like' 5-10+ degrees added to ambient temp.  Can actually get by with just fans, although still enough produced to run the ACs, if not too abusive.

 

Bad ... takes a good part of the day to recharge the ESS.  Instead of topped up before 1000 hrs, it's taking till 1400 hrs.   Although you can tell when I charged the MC.   Got back from the park with the dog just as it started to drizzle a bit of rain.

 

 

Also backed a Cheesecake for about 1 hr worth of appliances, and wife on the sewing machine, all day.   Certainly not charging the car, though don't need to.

 

The rain part is, just an annoying (if on scooters) drizzle now & than.   Shies are almost 100% clouds, light, allowing sun through, to very ominous dark gray, but not much rain.

 

A bit better than overcast & heavier rain, as that would probably knock production down to 10 ish kWh a day.   Needing 6kWh over night, if minimal AC, or just fan on, while sleeping.

 

[KhunLA]

That forecast is spot on ... again.   Another gray day ahead.  Although, already producing a bit more than using.  That's with 1 AC going in the bedroom.

 

 

[KhunLA]

Sadly, our Solar System has hit a milestone, with our digital meter, installed about 2 weeks after Solar was installed, and almost 25 months to the day, on the digital meter. 

 

It broke the 1000kWh mark ... 

That's the same, as a few of our one month Solar production & consumptions numbers.  Took 25 months instead of 30 days.

 

So not quite 'off grid' ... average 40kWh a month, for ~฿130 a month.

 

 

Damn overcast skies & owning a BEV car.  Somedays, you just got to use the grid to charge the car.  Like today, since overcast this week, haven't bothered.  Then the bank calls and tells you that your visa extension paperwork is ready.   Say what, only took 3 days instead of a week.  Oh crap ... got to charge the car.

 

And now, charging, as ran it down to 28%, going to Imm office about 250kms R/T.  And plan on going O&A tomorrow 🙄

 

On the flip side, have produced 16+ MWh & consumed 15+ MWh.

For a saving from PEA of ~฿64,000  without even considering the petrol savings of what it would cost for 17k kms worth of liters of 91 @ ฿36 (~฿43.7k)

 

 

Guesstimate would be about 250kWh went to house/inverter, average 10kWh a month & 750+ going to the BEV (car), average 30kWh a month.

[KhunLA]

 

[KhunLA]

If planning on having Solar & BEVs for transport, then size you system accordingly, if wanting to be almost off grid. We did not, but have plenty of excess solar ... usually 

 

An example of local exploring and charging with solar.

[KhunLA]

Interesting stuff ... 

 

... ours are inside, in AC comfort, along with hitting 100% everyday.  We wake up with ESSs @ ~60%, so usually 8kWh or less overnight of our 20kWh of ESS.

 

Going to put a small system outside soon, and already thought about using a shed with small AC unit.  Maybe in conjunction with a chicken coop.

 

 

 

 

[UWEB]

1 hour ago, KhunLA said:

Interesting stuff ... 

 

... ours are inside, in AC comfort, along with hitting 100% everyday.  We wake up with ESSs @ ~60%, so usually 8kWh or less overnight of our 20kWh of ESS.

 

Going to put a small system outside soon, and already thought about using a shed with small AC unit.  Maybe in conjunction with a chicken coop.

 

 

 

 

But who is discharging his Solar Batteries to zero, I guess nobody.

[Muhendis]

2 hours ago, KhunLA said:

Going to put a small system outside soon, and already thought about using a shed with small AC unit. 

There are a number of heat sources in solar power production some of which don't care if the ambient temperature goes up a bit (within reason).

 

There is no point to waste A/C power trying to keep inverters etc. at 25ºC. It would be more energy efficient to enclose just the batteries and control the temperature of that enclosure.

 

That figure of 25ºC is an older standard, particularly important for lead acid batteries, which can be increased to 30ºC for LiFePO4's and Lead Carbon batteries.

 

Added to that I have long been advocating to charge batteries to less than 100%. It is far less stressful on the chemistry and will prolong the battery's life if it is only charged to (say) 95%.

[KhunLA]

1 hour ago, UWEB said:

But who is discharging his Solar Batteries to zero, I guess nobody.

 

Yea, I certainly wouldn't, and actually couldn't in reality.  Would take a week of little production and heavy use.  If the weather is that crappy, I probably wouldn't need the ACs that much.  OK, could charge the car overnight, but that would be silly.

 

After the 2nd bank was added, don't think they've ever been below 50%.

 

45 minutes ago, Muhendis said:

There are a number of heat sources in solar power production some of which don't care if the ambient temperature goes up a bit (within reason).

 

There is no point to waste A/C power trying to keep inverters etc. at 25ºC. It would be more energy efficient to enclose just the batteries and control the temperature of that enclosure.

 

That figure of 25ºC is an older standard, particularly important for lead acid batteries, which can be increased to 30ºC for LiFePO4's and Lead Carbon batteries.

 

Added to that I have long been advocating to charge batteries to less than 100%. It is far less stressful on the chemistry and will prolong the battery's life if it is only charged to (say) 95%.

 

Knowing me, well, the wife, she won't be building a shed just for battery, but small sitting area.   Going by the small greenhouse she built, sized about the same as 1 bdrm / 1 bath single story detached house.  Bigger than the daughter's newest condo rental, I think.

 

But honey ... your figs take up a lot of space ... 🙄

[Muhendis]

1 hour ago, KhunLA said:

 

Knowing me, well, the wife, she won't be building a shed just for battery, but small sitting area.   Going by the small greenhouse she built, sized about the same as 1 bdrm / 1 bath single story detached house.  Bigger than the daughter's newest condo rental, I think.

 

But honey ... your figs take up a lot of space ... 🙄

 

Ahaa. 

The wifey.

That's a heat source I hadn't considered.

You could be quite reasonably consider a 3MW inverter A/C for that I expect.

Any further talk of your 'figs' and I will be tempted to report you.

[KhunLA]

On 8/1/2024 at 6:54 AM, KhunLA said:

 

Catching up to present month.  August a bit more than Sept, Oct, Nov, and latter 3, not much difference.  Only a couple days, exploring all day locally.  

 

[KhunLA]

Going to be one of those days.   Just now 1050 hrs, starting to produce a wee bit.   About 3 hours later than usual.

 

Do have the one AC on, and draw is minimal, 264w, for whole house, 13k BTU (at temp 29C) and 2 frigs.  Bedroom comfy, low RH, and not even using fan.

 

ESSs @ 45%, and hopefully back to 100% before nightfall.  Everything charged up, plenty of leftovers in frig, so no cooking needed.  Off & on rain, so wife won't be welding outside.

 

Shy of 1 kWh going to ESS, and 6 hrs will only bring it up to ~75%.  Clouds should break sooner or later 🙄

 

Low use day unless we get some full on sun.  Guess we'll just have to hang out in the bedroom 

[KhunLA]

54 minutes ago, KhunLA said:

Clouds should break sooner or later 🙄

Apparently sooner than later 😎

3kWh per ... 100% in 3 hours 👍

 

[KhunLA]

ebike

MG ZS EV

Deco SuSu

MI air purifiers

ACs

Oven (baking bread)

 

Pulling 5-6kWh ... all of ฿20 - ฿25 an hour.  I can retire soon 

 

 

 

[KhunLA]

2024 ... Production 7.74 MWH = 645kWh monthly = ฿2,853 (PEA)

฿2,853 x 12 = ฿34,236 Saved + petrol savings of ~฿42,500 ***

Total 'potential' savings for 2024 = ฿76,736

 

 

*** Petrol savings based on 17k kms all local, all solar charged,

vs Bangchak price for 91 @ ฿35 (14kpL)

[KhunLA]

 

Least use day

 

Most use day

 

 

App upgrade, with new stats provided ...

... Average daily use - 13.85kWh

... Average overnight (14 hrs) battery use - 4.42kWh

 

[KhunLA]

[ExpatOilWorker]

On 7/1/2024 at 5:47 AM, KhunLA said:

What happened from July 10-24th?

Curtailment? You were traveling and the house was empty?

Usually July are sunny days in ur area.

 

[KhunLA]

5 minutes ago, ExpatOilWorker said:

What happened from July 10-24th?

Curtailment? You were traveling and the house was empty?

Usually July are sunny days in ur area.

 

Yea ... and your point ?

 

As you guessed, yes, out of town.  That's all the house uses, so that's all that needs to be produced.   That's how solar works, feeds the load/draw of appliances, and recharges the ESS/batteries, from their use overnight.   

 

  That's June 2024, BTW, and when out of town (just checked) and uses ~4kWh a day, producing ~5kWh a day.  Only thing drawing power, probably just the 2 frigs, and 1 light.

[ExpatOilWorker]

13 minutes ago, KhunLA said:

Yea ... and your point ?

 

As you guessed, yes, out of town.  That's all the house uses, so that's all that needs to be produced.   That's how solar works, feeds the load/draw of appliances, and recharges the ESS/batteries, from their use overnight.   

 

  That's June 2024, BTW, and when out of town (just checked) and uses ~4kWh a day, producing ~5kWh a day.  Only thing drawing power, probably just the 2 frigs, and 1 light.

I was looking through your charts to get an idea of the lowest power generation during rain and cloud covers.

What is the lowest production you have seen over a 5 days period?

You have a 8 kW inverter, right? 9,720 W panels?

My point, was to figure out how much is gained by oversizing the solar array.

I am considering a 5 kW inverter with  9,000 W of panels and 15 kWh of batteries. Reasonably or way off?

 

[BritManToo]

25 minutes ago, ExpatOilWorker said:

I was looking through your charts to get an idea of the lowest power generation during rain and cloud covers.

What is the lowest production you have seen over a 5 days period?

You have a 8 kW inverter, right? 9,720 W panels?

My point, was to figure out how much is gained by oversizing the solar array.

I am considering a 5 kW inverter with  9,000 W of panels and 15 kWh of batteries. Reasonably or way off?

 

Zero when it's raining.

But the worst I've had in 3 years was 3 days that didn't last through the night.

Not really a worry as it grabs from the grid if required.

10 x 580 mono bifacial would be enough for a starter.

[KhunLA]

1 hour ago, ExpatOilWorker said:

I was looking through your charts to get an idea of the lowest power generation during rain and cloud covers.

What is the lowest production you have seen over a 5 days period?

You have a 8 kW inverter, right? 9,720 W panels?

My point, was to figure out how much is gained by oversizing the solar array.

I am considering a 5 kW inverter with  9,000 W of panels and 15 kWh of batteries. Reasonably or way off?

 

BM2 answered part of your query.  Need to be careful about to many panels, and need to stay within voltage level the inverter will accept.

 

Without that concern, and crappy days, you have more panels, exposure to light, and produce more.  I've yet to need the grid, since installed.  There have been crappy days, when it took all day to top up the batteries before night fall.  So far, not too many of those days, in a row.

 

Amazing how much they will produce, even when crappy out.  Of course when it is overcast & rainy, we really don't need the ACs as much, so can easily get by an ~10kWh for the day.

 

Good sunny day, and we're using ACs & charging the car, we can easily use ~50kWh.   I think that's about the max that we've used.  I stopped paying attention about max use, and most things.

 

Here's one I did note, 5 May 2023, and thet never hit max production, so not that sunny out.  We've had 1000+kWh of use a few months a year ... 

 

 

 

 

[KhunLA]

@ExpatOilWorker We don't need the grid at all for the house, though still connected.  First couple weeks, Aug 2022, testing the system functions, we used some grid, and fed some to the grid, (noted below) but after the 18th of he month. I think, we got the digital meter, and don't use the grid for the house.

 

[ExpatOilWorker]

16 minutes ago, KhunLA said:

@ExpatOilWorker We don't need the grid at all for the house, though still connected.  First couple weeks, Aug 2022, testing the system functions, we used some grid, and fed some to the grid, (noted below) but after the 18th of he month. I think, we got the digital meter, and don't use the grid for the house.

 

Right, you basically curtail power generation on most normal days.  I am not really concerned about sunny days, they will always produce more than needed.

Crossy is getting 20 kWh out of his 23 kW panels on rainy days.

Similar it looks like you are getting 8-10 kWh out of your 9.7 kW panels.

Do you recall the lowest couple of days you have ever had?

 

[KhunLA]

26 minutes ago, ExpatOilWorker said:

Right, you basically curtail power generation on most normal days.  I am not really concerned about sunny days, they will always produce more than needed.

Crossy is getting 20 kWh out of his 23 kW panels on rainy days.

Similar it looks like you are getting 8-10 kWh out of your 9.7 kW panels.

Do you recall the lowest couple of days you have ever had?

 

Probably the 1st month of having, as we were being really conservative, to see how little we could get by on, along with only having the one ESS then, and would wake up to 35% remaining.

 

Aug 2022 having a lot of 10kWh +/- days.  Guessing at end of the month, we were out of town. 

 

Unless high temps and heavy AC use, we only use 15-20kWh a day, unless charging the car.  30-35kWh a day if heavy AC use.  Knocking on 50kWh a day if ACs & charging car.

 

You can also see the days, we were experimenting with exporting, so produced more also.  We got the digital meter on the 20th.

 

https://aseannow.com/topic/1268214-solar-8kw-hybrid-inverter-w10kwh-upgraded-to-20kwh-in-sept-2022-essbattery-not-diy/#comment-17556154

 

graph for Aug 2022

 

Here's one of, if not the lowest producing day, when we were home.  8.2kWh

 

https://aseannow.com/topic/1268214-solar-8kw-hybrid-inverter-w10kwh-upgraded-to-20kwh-in-sept-2022-essbattery-not-diy/page/4/#findComment-17734118

 

[ExpatOilWorker]

12 hours ago, BritManToo said:

Zero when it's raining.

But the worst I've had in 3 years was 3 days that didn't last through the night.

Not really a worry as it grabs from the grid if required.

10 x 580 mono bifacial would be enough for a starter.

Zero might be a bit on the low side.

Crossy's all time low is 13.9 kWh from 11 kW of panels on a cloudy ⛅️ October in 2023.

What was your all time daily low and at what size array?

 

[ExpatOilWorker]

16 hours ago, KhunLA said:

Probably the 1st month of having, as we were being really conservative, to see how little we could get by on, along with only having the one ESS then, and would wake up to 35% remaining.

 

Aug 2022 having a lot of 10kWh +/- days.  Guessing at end of the month, we were out of town. 

 

Unless high temps and heavy AC use, we only use 15-20kWh a day, unless charging the car.  30-35kWh a day if heavy AC use.  Knocking on 50kWh a day if ACs & charging car.

 

You can also see the days, we were experimenting with exporting, so produced more also.  We got the digital meter on the 20th.

 

https://aseannow.com/topic/1268214-solar-8kw-hybrid-inverter-w10kwh-upgraded-to-20kwh-in-sept-2022-essbattery-not-diy/#comment-17556154

 

graph for Aug 2022

 

Here's one of, if not the lowest producing day, when we were home.  8.2kWh

 

https://aseannow.com/topic/1268214-solar-8kw-hybrid-inverter-w10kwh-upgraded-to-20kwh-in-sept-2022-essbattery-not-diy/page/4/#findComment-17734118

 

Perfect, the 8.2 kWh number was exactly what I was looking for and it looks like that can easily happen 3 days in a row.

Meaning even on extreme low solar days the panels still deliver approximately 1 hour of nominal rating.

On the other end, looks like it is also possible to get 6 hours or almost 50 kWh on the 18th of August. 

Good stuff, thanks.

The Inverter has 2 strings of 600 V, so I am considering 2×10 of the below panels, if I have the roof space.

 

[KhunLA]

@ExpatOilWorker

Do you know how many kWh you are using a month now ?  If so, base your system's minimal production on your highest usage month.

 

8kW inverter w/20kWh ESS is enough, (just some days), BUT, there is only 2 of us, and at nightfall, we're basically in the bedroom (also TV / vid room) till we wake the next day. 

 

Maybe a snack mid way thru the night, but very little electric use.  About 8kWh overnight (14 hour period) and wake up to about 60% remaining in ESS.  Like to stay above 50%, for longevity of batteries, and, if a couple crappy days in a row,  that could be an issue, getting back 100-90-80%, first day, then less the next day.

 

Hasn't happened yet, but again, it's just the 2 of us, and 1 room basically at night.  So as stated in the thread; 1 AC, 1 TV, 2 laptops & 2 frigs are all that's running.

 

If daughter lived here, that would be another of the same.  Would have gone with two 5kW inverters & 30kWh of ESS, if not 3 inverters.

[ExpatOilWorker]

10 hours ago, KhunLA said:

@ExpatOilWorker

Do you know how many kWh you are using a month now ?  If so, base your system's minimal production on your highest usage month.

 

8kW inverter w/20kWh ESS is enough, (just some days), BUT, there is only 2 of us, and at nightfall, we're basically in the bedroom (also TV / vid room) till we wake the next day. 

 

Maybe a snack mid way thru the night, but very little electric use.  About 8kWh overnight (14 hour period) and wake up to about 60% remaining in ESS.  Like to stay above 50%, for longevity of batteries, and, if a couple crappy days in a row,  that could be an issue, getting back 100-90-80%, first day, then less the next day.

 

Hasn't happened yet, but again, it's just the 2 of us, and 1 room basically at night.  So as stated in the thread; 1 AC, 1 TV, 2 laptops & 2 frigs are all that's running.

 

If daughter lived here, that would be another of the same.  Would have gone with two 5kW inverters & 30kWh of ESS, if not 3 inverters.

20 kWh/day should cover 90% of my usage, which is almost all AC usage:

2,000 W aircon (2 × 9,0000 BTU)

500 W pool pump (4 hours/day)

50 W TV

150 W fridge

150 W LED lights + fan + wifi

200 W water pump (1/2 hour/day)

 

Very intermittent low usage:

1,800 W vacuum cleaner

600 W toaster

800 W nespresso 

 

Is it straight forward and trouble free to add an extra inverter and battery on an existing system?

If yes, then I could start out with:

5 kW inverter

20 kWh (4 × 5 kWh) battery 

12,800 W panels

 

What do you think?

 

Last, but an important question.  We do have the occasional power cut for an hour or two.

Is it possible to set the inverter never to go below 20% battery, so as to keep the last 20% as an UPS function?

[Crossy]

1 hour ago, ExpatOilWorker said:

Is it straight forward and trouble free to add an extra inverter and battery on an existing system?

If yes, then I could start out with:

5 kW inverter

20 kWh (4 × 5 kWh) battery 

12,800 W panels

 

What do you think?

 

Last, but an important question.  We do have the occasional power cut for an hour or two.

Is it possible to set the inverter never to go below 20% battery, so as to keep the last 20% as an UPS function?

 

A qualified yes to all.

 

IF you get an inverter that's well supported and can run in parallel. 

 

We have 4 x 5kW Deye hybrids running together, they will do everything you want and more, there are offers available on these for as little as 23kBaht on Lazada with vouchers. They are also on the PEA approved inverter list.

 

Do note that a 5kW inverter likely can't support more than 6kWp of panels.

 

You may find that larger battery packs are more economical on a bang-per-buck level (and less wiring needed).

 

Is this going to be a DIY or Contractor install??