Solar Power for Home

[Crossy]

10 minutes ago, BritManToo said:

Built my own, it's just 16 batteries linked + to - in a long line, then a BMS added.

Careful with the socket driver, easy to get a big bang if you brush it against another battery terminal.

(Yeah, I did it a couple of times)

 

Applying heat-shrink to your long metal tools is a smart move, reduces the possibility of an exciting splat!!

[lom]

6 hours ago, Crossy said:

As to sunny/vs overcast, we can vary between >70kWh on a nice day to <20kWh on a damp and miserable day (we have 18kWP of solar, you do the sums).

Don't be shy, with 18KWp of solar you should be able to get over 80KWh on a good day.

Today is the first really sunny day with all blue sky here in Samui and I could have got 70++ KWh out of my 14.5KWp panels if I just had consumers for it, the max I have ever logged was 64KWh.

This is todays curves until 12:00, starting with a SoC of 38% at 7:00 when production took on and ending at 87% so I still have almost an hour until batteries are full. The blue production curve would look the same but in the falling direction until 17:00 if only I had something to load the panels with. 😀  

Edited August 10 by lom

[KhunLA]

18 minutes ago, lom said:

Don't be shy, with 18KWp of solar you should be able to get over 80KWh on a good day.

Today is the first really sunny day with all blue sky here in Samui and I could have got 70++ KWh out of my 14.5KWp panels if I just had consumers for it, the max I have ever logged was 64KWh.

This is todays curves until 12:00, starting with a SoC of 38% at 7:00 when production took on and ending at 87% so I still have almost an hour until batteries are full. The blue production curve would look the same but in the falling direction until 17:00 if only I had something to load the panels with. 😀  

Nice and sunny out now, though still patchy clouds, and still produced 22+kWh already.  Don't export, so will only produce what's needed after ESSs are topped up.

 

Even then, best was about 6kWh, so still a bit overcast then and not prime exposure to the panels.

 

 ESS top up before 1100 hrs, from last night (8kWh), while both ACs on (13&24BTUs).  Topping up car (only 4kWh), and got the MC Q'd up to charge when that is done.  And it's only 1244 hrs

Edited August 10 by KhunLA

[Crossy]

23 minutes ago, lom said:

Don't be shy, with 18KWp of solar you should be able to get over 80KWh on a good day.

 

We are rather limited by our battery capacity since we don't export and are operating basically off-grid. A sunny day after the batteries get depleted would be the ideal situation.

 

The long weekend will be a test as we have family here for 3 days so all the A/C will be running. Hopefully we won't need to import.

[arick]

4 hours ago, atpeace said:

@KhunLA 

Exactly the data I need.  I have some older panels from my camper(3x180w) that I installed years ago (wrong angles and other issues 🙂  ).  This gives me a better idea of the potential.

 

I got tired of flip flopping on the installation yesterday and just got in the car and drove to a solar shop in the sticks.  Not much around here and I haven't seen any houses with solar.  Solar here is mostly on  farms and fish ponds (500-1000 w).

 

Spent 3 hours talking to a nice kid that just expanded his solar shop last week.  Last visit a year ago he had only a few panels and I had to step over piles of wires just to get into the shop.  Now he has a nice setup with loads of panels to choose from.  I decided to just do it and put down a 5k deposit.  He will tentatively start the installation next week.  Only charging 2 baht per watt to mount panels and wire. I was going to do much of it myself but at this price, I will just be an observer.

 

I anticipate lots of issues with the install and I'm a patient person so that will be only a minor inconvenience.  The kid (22 yo) is nice and has been doing installations on farms and some houses for at least  a few years.  What could go wrong 🙂

 

This home was not intended to be a permanent residence (covid lockdown build ) but have slowly consolidated and now this is my only property.  My partner has others that we rarely visit in Jomtien  and Lamphang.  She likes it here and at this point I fear I have no choice but to call this home 🙂

 

Below is a quick spreadsheet I just did of the setup.  I want this to do this for <90k but no issue if I blow through that number.  

 

My setup ( should I oversize the panel production while staying under voltage limits of inverter??? ) I'm guessing my max elec units a month will be 550 watts April - June and be well under for most other months.  

 

 

 

 

 

Yes I have calculated the same price. I will buy myself and find somebody good to install it. There is no need to hire a company that charges 200,000

[atpeace]

17 minutes ago, arick said:

Yes I have calculated the same price. I will buy myself and find somebody good to install it. There is no need to hire a company that charges 200,000

Well, we are going to find out soon enough.  There are a few here that did spend lots of cash on their setups that are willing to help new installers on a tighter budget which is nice.   If it was 5 years ago, I would have needed much more assistance with the project but much easier today.

 

I have time and look at it as an adventure.  I'm sure I'll make a many mistakes along the way but past worrying too much about the consequences.  The hardest part is pulling the trigger and starting the project.   Did that yesterday.  Now I can stop going off on countless tangents and go with the plan in place.

[atpeace]

1 hour ago, Crossy said:

 

We are rather limited by our battery capacity since we don't export and are operating basically off-grid. A sunny day after the batteries get depleted would be the ideal situation.

 

The long weekend will be a test as we have family here for 3 days so all the A/C will be running. Hopefully we won't need to import.

I understand the desire to be off the grid but isn't it more cost effective to be off 80-100%?  If the goal is to be off the grid you need a big buffer in battery size and solar production.  Probably ~ 40% more capacity/storage. 

 

If the grid were to go down on a day that I was only producing/storing 80% of the needed power, I could make some minor electric adjustment to bring the 80% to 100%.

[sandyf]

4 hours ago, BritManToo said:

Solar electricity costs double coal electricity.

More solar and less coal/oil will mean huge electricity price increases

Two thirds of Thailands generation is by natural gas, coal hardly has a look in.

It cannot be assumed that the costs of today will be the costs of tomorrow and if people want to put money into home installations that is entirely up to them.

My annual electricity costs are not a great deal more than they were 10 years ago so any ROI is unlikely to be less than my life expectancy.

[KhunLA]

1 hour ago, atpeace said:

I understand the desire to be off the grid but isn't it more cost effective to be off 80-100%?  If the goal is to be off the grid you need a big buffer in battery size and solar production.  Probably ~ 40% more capacity/storage. 

 

If the grid were to go down on a day that I was only producing/storing 80% of the needed power, I could make some minor electric adjustment to bring the 80% to 100%.

With our high priced install, with the EVs, and if still driving as we do, 22.5k kms a year, I expect ROI in <10 yrs.   If all local driving, and continued abuse of AC at house, then that could easily be 4-6 yrs.

 

Our system (8kW inverter w/20kWh of ESS) is more than enough for the 2 of us, and the 2nd ESS (10kWh), was only added for getting longevity out of them, as they now rarely go below 60%.

 

So 1 cycle every 3 days or so.  They'll outlast me, if no oops, and possibly the wife.   We also have 46.3 kWh of battery in the EV, if ever needed.

 

I consider both to be 2 of the best investments I ever made.   Depreciating products that will pay for themselves + ... for years to come.

Edited August 10 by KhunLA

[atpeace]

15 minutes ago, KhunLA said:

With our high priced install, with the EVs, and if still driving as we do, 22.5k kms a year, I expect ROI in <10 yrs.   If all local driving, and continued abuse of AC at house, then that could easily be 4-6 yrs.

 

Our system (8kW inverter w/20kWh of ESS) is more than enough for the 2 of us, and the 2nd ESS (10kWh), was only added for getting longevity out of them, as they now rarely go below 60%.

 

So 1 cycle every 3 days or so.  They'll outlast me, if no oops, and possibly the wife.   We also have 46.3 kWh of battery in the EV, if ever needed.

 

I consider both to be 2 of the best investments I ever made.   Depreciating products that will pay for themselves + ... for years to come.

You have built a masterpiece and I'm just wanting something that will cover close to 100% of my electric needs most days and over 75% on the bad days.  I Have no issue with using the grid.  I think your system is wonderful but overkill for simple me with no EV and no desire to provide 100% of my electric from solar.  I've been looking at your setup for months and am jealous to some extent.

 

I think 6.6kWh solar with 280ah 48v battery will get me to close to 100%.  What do you think? 

Edited August 10 by atpeace

[BritManToo]

25 minutes ago, atpeace said:

I think 6.6kWh solar with 280ah 48v battery will get me to close to 100%.  What do you think? 

My house is powered by a 5k5 inverter + 3k solar panels + 5 kwhr of battery. I split my fusebox so cooker, shower heaters and Aircon are powered direct from the grid.

 

That does 80% of my needs, my battery should have been double that. At the moment it's empty by 9am.

 

My monthly pea bill is 50-80 units (around 300bht).

 

It only takes the wife to shower (4.5kw), and the kid to use the other shower (4.5kw) at the same time = 9kw out of a 5k5kw inverter. So I left them on grid.

Edited August 10 by BritManToo

[JBChiangRai]

I have 28.8KwHrs of LFP batteries, 18Kw of grid-tied inverters and 16.5Kw of Hybrid inverters (currently used as UPS), however, if I was to do it again, I would do away with the batteries and go grid-tied 6-10Kw of inverter.

 

My issue with batteries is they are cycled too often and are very expensive to replace in 5-10years.

[Snackbar]

Everything Chinese is getting cheaper by the the min

[xtrnuno41]

I hope Bandersnatch dont mind putting up this/his link of his house in solar panels.

https://ecohousethailand.com/

Very detailed docu.

Or voltage stabilizers

Choose a stabilizer with a broader voltage range than your appliance, preferably 10% to 15% more. For example, if your device has a voltage range of 180 V to 240 V, you should choose a stabilizer that has a voltage range of at least 162 V to 276 V. This will ensure that the stabilizer can regulate the voltage of the appliance in case of extreme fluctuations and provide enough margin for safety and efficiency.

And of course for the power (Watts) you need. 

[Crossy]

3 hours ago, atpeace said:

I understand the desire to be off the grid but isn't it more cost effective to be off 80-100%?  If the goal is to be off the grid you need a big buffer in battery size and solar production.  Probably ~ 40% more capacity/storage. 

 

If the grid were to go down on a day that I was only producing/storing 80% of the needed power, I could make some minor electric adjustment to bring the 80% to 100%.

 

We never really intended to go off-grid, but I got a great deal on a stack of panels and batteries from the estate of a mate who sadly dropped dead (ok he drank way too much). His widow just wanted rid of the stuff that he'd acquired over the years so she could sell off their house in Don Mueang. No, I didn't rip her off, I'm not that type of guy, we agreed a sensible price for "new old-stock" on cells and panels. It just so happened that I had just ordered 28kWh of new batteries from China so we've ended up with rather more generation and storage than I'd anticipated.

 

Of course, Madam has designs on an EV and to enclose our large downstairs living area which will require A/C.

 

I've long since given up on any idea of ROI, I'm an engineer doing what engineers do (keeps the little grey cells active (c) Hercule Poirot).

[KhunLA]

14 minutes ago, Crossy said:

 

We never really intended to go off-grid, but I got a great deal on a stack of panels and batteries from the estate of a mate who sadly dropped dead (ok he drank way too much). His widow just wanted rid of the stuff that he'd acquired over the years so she could sell off their house in Don Mueang. No, I didn't rip her off, I'm not that type of guy, we agreed a sensible price for "new old-stock" on cells and panels. It just so happened that I had just ordered 28kWh of new batteries from China so we've ended up with rather more generation and storage than I'd anticipated.

 

Of course, Madam has designs on an EV and to enclose our large downstairs living area which will require A/C.

 

I've long since given up on any idea of ROI, I'm an engineer doing what engineers do (keeps the little grey cells active (c) Hercule Poirot).

My initial contact with our installer, was for a 6.3kw hybrid inverter, no batteries, and about 150k.

 

At the time, I asked for different prices for different sizes, and it worked it's way up to 200k to 200k+, then with ESSs 5-10-20kWh, and we were into 400+k and I said  ...

 

... 'do ding dong people actually spend this kind of money for solar' 

 

... 'yea, some do, others just use the grid as battery at night & roll back their meters'

 

... and the rest is history ... 

[Elkski]

Messing around with solar is a benefit of living in Thailand.  Here in USA metering buyback rates so  low, component prices much higher.   Solar companies want to profit so much.   Fir kicks a couple months ago I went ahead and had a door to door solar salesman cook up a system for me.   He did see my monthly power usage but not day night use.   

A different guy came by a few days later saying it was 45k USD for 9 kw system.  This did include a new roof.  I haven't got a quote on a new roof but I guess it could be 12-15k$. 

It was a micro inverter system using USA made panels.    The deal was I pay 115$/no and after 20 years the system was mine.   I guess he could tell by my questions he didn't have an eager buyer and never did his follow up call.   

I wasn't real impressed by the software that took Google roof image and put 2 panels behind a chimney.   He said the final version wouldn't make that mistake.  

I see lots of panels put on east and west facing roofs.  Just do to the roof layout.  Plus the optimum angle here is 33.9. facing South.   actually adjusting the angle from 19-50 degrees is max efficient.  Don't quote those angles.   Here they hardly ever use angle brackets.  They just go with roof slope which varies from 4-8/12 roof pitch. I guess due to wind and snow  and ease of install and maximum watts.   I see lots of installs where neighbors tree shades it much of the day.   These solar companies are crooks as far as I'm concerned. Power bill in July was  14,000 baht. Increase of 3 k over June ?  The highest ever.  It was hot and maybe using air con to much, or Tennant has a grow, or the new hot tub but heater is off for summer.   If I do solar I would want to cut out the salesman commissions and high profit somehow.  

[atpeace]

1 hour ago, Crossy said:

 

We never really intended to go off-grid, but I got a great deal on a stack of panels and batteries from the estate of a mate who sadly dropped dead (ok he drank way too much). His widow just wanted rid of the stuff that he'd acquired over the years so she could sell off their house in Don Mueang. No, I didn't rip her off, I'm not that type of guy, we agreed a sensible price for "new old-stock" on cells and panels. It just so happened that I had just ordered 28kWh of new batteries from China so we've ended up with rather more generation and storage than I'd anticipated.

 

Of course, Madam has designs on an EV and to enclose our large downstairs living area which will require A/C.

 

I've long since given up on any idea of ROI, I'm an engineer doing what engineers do (keeps the little grey cells active (c) Hercule Poirot).

Well that sounds fun and I'm not really concerned about ROI either but still relatively young and need to make my early retirement( retired 2008 at 41) dollars get me to at least to when my pensions kick in  about 10 years from now.   

 

My home here is small but per square meter my electric needs are high.  Only 2 bedrooms and the living space between the two rooms is open (screened -darn mosquitos ).  Strange setup but I like it. Good airflow and easy to cook and hangout.  Simple life!

[atpeace]

3 hours ago, BritManToo said:

My house is powered by a 5k5 inverter + 3k solar panels + 5 kwhr of battery. I split my fusebox so cooker, shower heaters and Aircon are powered direct from the grid.

 

That does 80% of my needs, my battery should have been double that. At the moment it's empty by 9am.

 

My monthly pea bill is 50-80 units (around 300bht).

 

It only takes the wife to shower (4.5kw), and the kid to use the other shower (4.5kw) at the same time = 9kw out of a 5k5kw inverter. So I left them on grid.

Remember you posting that info on another thread minus the shower info.  I didn't think about that but the showers might be an issue.  We never have 2 on at the same time but still 4.5kw would quickly max out the 6.2 kw inverter.  Wiring different breakers to only be used by the grid seems complicated.  Hopefully the young kid doing this can figure it out.  Is it really an issue though because the Anern inverter would just switch over to the grid for the extra power needed?  

[worrab]

On 12/14/2023 at 2:44 AM, KhunLA said:

  No practical plan to buy back excess.

I will be having solar panels installed on our new property in Hua Hin. This will be returning back to the PEA during daytime. All paperwork is being done by the installation company as there is a fair amount to do!! We pay our bill as normal then the PEA does cash back every few months. 

[cowellandrew]

Mine work great 😁😂😬

 

[lom]

15 hours ago, atpeace said:

didn't think about that but the showers might be an issue.  We never have 2 on at the same time but still 4.5kw would quickly max out the 6.2 kw inverter. 

 Any decent grid connected inverter will output up to its specified limit (~ 6KW in you case) and whatever else is needed by consumers will be taken from the grid.

[xtrnuno41]

19 hours ago, worrab said:

I will be having solar panels installed on our new property in Hua Hin. This will be returning back to the PEA during daytime. All paperwork is being done by the installation company as there is a fair amount to do!! We pay our bill as normal then the PEA does cash back every few months. 

Wait for the changes. In "my country" at first, you could have quite a profit on delivering back.

Then problems in grid, and they could shut down your inverter and you werent able to deliver back. So no money.

 

Due to war, many people installed panels. And now they, energy selling companies, say, you HAVE TO PAY for delivering back ! Market for panels has collapsed. And all the ones with panels, need a longer time for invest return.

The panels are real cheap now and installing companies are dying to get orders in. 

There was a time, they were fully booked on work. You couldnt find an installing company, come back next year .

They mention now better to SPILL your electricity, then delivering back, as you must pay !

Remove your gas heater and make it 2 way airco, water heater the same and have nice hot showers.

Only now they are pumping up the price of water.

Or of course start using batteries, buy an electric car.  

[atpeace]

On 8/10/2024 at 6:08 PM, KhunLA said:

My initial contact with our installer, was for a 6.3kw hybrid inverter, no batteries, and about 150k.

 

At the time, I asked for different prices for different sizes, and it worked it's way up to 200k to 200k+, then with ESSs 5-10-20kWh, and we were into 400+k and I said  ...

 

... 'do ding dong people actually spend this kind of money for solar' 

 

... 'yea, some do, others just use the grid as battery at night & roll back their meters'

 

... and the rest is history ... 

An installer is arriving at 10am but assume in contracter time that means sometime today 🙂

 

Anyhow, he sent a picture of the solar combiner box last night as a confirmation, I think,  that he would be coming. I notices he had 4 PV inputs and I was expecting 2.  There will be 12x550w (15amp) panels and was going to go with 2 string with each string at 300 volts ( 6x50v).  The inverter needs 60v-450v of PV input.  His 4 strings would provide 150v per string vs 300v of my 2 strings.

 

My rationale for only two strings is that it would be slightly more efficient in early morning and late afternoons.  Also on cloudy days.  

 

Is it really worth worrying about?  Below is the panel layout.

 

[KhunLA]

31 minutes ago, atpeace said:

An installer is arriving at 10am but assume in contracter time that means sometime today 🙂

 

Anyhow, he sent a picture of the solar combiner box last night as a confirmation, I think,  that he would be coming. I notices he had 4 PV inputs and I was expecting 2.  There will be 12x550w (15amp) panels and was going to go with 2 string with each string at 300 volts ( 6x50v).  The inverter needs 60v-450v of PV input.  His 4 strings would provide 150v per string vs 300v of my 2 strings.

 

My rationale for only two strings is that it would be slightly more efficient in early morning and late afternoons.  Also on cloudy days.  

 

Is it really worth worrying about?  Below is the panel layout.

 

Someone more techie is going to need to answer that one.  I'm assuming they are on a different pitch, and the roof crown is at the 3m mark.

 

Our strings, 2, face due S & W.  I wanted to put  some on E pitched veranda roof, but installer was skeptical about the added weight.  So we lose about 2 hours max of more production.   

 

The roofs has a very slight pitch, so S starts producing more than using about 0730 hrs.  By 0800, and we got both ACs running, and still sending some to the ESS.

 

Not looked, but I think around 0800 hrs, or earlier and W panels probably are fully exposed to the sun.

 

Unless over cast, or charging the EV, ESS are topped usually before 1000 - 1100 hrs.  

 

Here's a day of sunshine in March, while O&A, slow till about 0800, then increases quite fast.  So guessing both strings exposed by then.   Since not home, ESS top up fast.  Just 2 frigs & 1 light on.  14 hours of non production, and <5kWh produced, and <4kWhh used  for just them, when not home.

Edited August 14 by KhunLA

[lom]

1 hour ago, atpeace said:

His 4 strings would provide 150v per string vs 300v of my 2 strings.

 

There are two common types of combiner boxes, 2 to 1 and 4 to 2. If you want 2 strings out then it is the 4 to 2 box and you don't need 4 input strings for it, he can use it as 2 to 2. Now you may ask why the need for a combiner box if 2 to 2, that is because the box contains input string fuses, output string breakers, and surge protectors. You can't run the 2 strings from the panels directly to your inverter, you need a combiner box in between.

Edited August 14 by lom

[atpeace]

Thanks - simple flat steel rough 12mx8m.  All same pitch which is slightly leaning away from the sun.  I have tilted flat on my existing panels and the PV amps only increase 2-4%. 

 

I have a gap 4m not 3m as in the diagram between because the two rooms with AC are on both sides of the gap.  I want the panels to block direct sun hitting the the rooftop in the AC rooms.  Should make a substantial difference to the vented attic space heat which isn't too bad but why not drop the temps even more.  Ordered more ceiling Be Cool brand insulation also for my exercise room that the AC struggles with keeping it cold.

[atpeace]

15 minutes ago, lom said:

There are two common types of combiner boxes, 2 to 1 and 4 to 2. If you want 2 strings out then it is the 4 to 2 box and you don't need 4 input strings for it, he can use it as 2 to 2. Now you may ask why the need for a combiner box if 2 to 2, that is because the box contains input string fuses, output string breakers, and surge protectors. You can't run the 2 strings from the panels directly to your inverter, you need a combiner box in between.

Oh, so the 4 input string on the bottom of the box are to accommodate 2 strings and not 4.  I think i get this now and it would probably apply to the battery I will be hooking up next week.  I would need to 2 breakers.  Input and output?  Thanks and hopefully I'm comprehending your message.

 

[lom]

The box in your photo is not a common one, it is actually a 2 to 2.  From left to right: 2 fuses for a string (+ and -), a dual pole breaker for output, and 2 surge protectors for a string (+ and -) , then followed by an identical set for the second string.

[atpeace]

12 minutes ago, lom said:

The box in your photo is not a common one, it is actually a 2 to 2.  From left to right: 2 fuses for a string (+ and -), a dual pole breaker for output, and 2 surge protectors for a string (+ and -) , then followed by an identical set for the second string.

They are here now- thanks