Obtained this quote from a local installer. We have a modest three bedroomed single storey house with 3 X 12,000 btu and 2 X 18,000 btu dual inverter air conditioners. No electric vehicle. Panels to be installed upon carport roof. Meter will require moving to the next power pole and the mains will then enter the house from the opposite end. This is included in the quote. Looks good to me but if anyone can spot any errors or omissions I'd be obliged. Thank you most kindly!

Solar Quote (English).pdf

14 minutes ago, The Fugitive said:

Obtained this quote from a local installer. We have a modest three bedroomed single storey house with 3 X 12,000 btu and 2 X 18,000 btu dual inverter air conditioners. No electric vehicle. Panels to be installed upon carport roof. Meter will require moving to the next power pole and the mains will then enter the house from the opposite end. This is included in the quote. Looks good to me but if anyone can spot any errors or omissions I'd be obliged. Thank you most kindly!

Solar Quote (English).pdf

Personally, with five air conditioners I would go considerably bigger. Probably around 18 panels, roughly 11 kW of solar, a 10 kW inverter and at least 16 kWh of battery. From there the sky is the limit, depending on how much independence from the grid you actually want.

I would also look closely at everything around the system, not only panels, inverter and battery. Proper breakers and safety breakers, surge protection, battery protection, correct cable sizes, and an overhaul of the existing electrical system in the house if needed.

The quote already includes quite a lot of this, including the distribution box, leakage and short circuit protection, battery breaker equipment, surge protection and grounding, which is good.

It is strange, once you first get a solar system you always seem to wish you had more. I oversized pretty much everything myself from the start, except the battery capacity, which I added to later on.

I cannot really comment on the price itself, because that depends a lot on the company doing the installation, factory guarantees, the quality of the components, and what the installer promises in terms of aftersales service.

I also think you need a bigger inverter etc.

You don't mention any brand names for inverter and battery.

Make sure you order reputable inverter and battery/ies.

For the submission of the documents, I heard (can't remember where, think it was my electrician) that for a 5kW system it was B5000, 10kW system B10000, 20kW system B20000. Not sure of any reason behind this, so your charge for this item seems high.

sorry, no comment on the quotation. i do notice that many people choose a solar system without first carrying out the necessary technical and consumption analysis. unfortunately, some solar companies also seem to consider these checks unnecessary ...

just a few technical thoughts on how i for myself would approach sizing a solar system :

1. analyse the actual electricity consumption:

• annual and monthly kwh

• average daily consumption

• daytime consumption, especially 08:00–17:00

• day vs. night loads

• expected future consumption, e.g. electic car, additional ac, family growth, etc.

2. check the electrical system:

• single- or three-phase connection

• smart meter

3. analyse the installation site:

• panel orientation and tilt

• shading throughout the day/year

• available roof area

• access for cleaning and maintenance

• potential for future expansion

4. define the objective:
   maximum self-consumption, bill reduction, only daytime load coverage, zero export or export to pea, etc

only after these parameters are known should the pv capacity, inverter and battery be sized ...

the goal should be an optimized system based on actual consumption and future requirements ...

5 KW inverter sounds too small to me too.

Seems the forum admin has allowed PDF's to be uploaded again.. great we'll be able to read technical drawings and immigration forms again.

1 hour ago, johng said:

5 KW inverter sounds too small to me too.

Seems the forum admin has allowed PDF's to be uploaded again.. great we'll be able to read technical drawings and immigration forms again.

Thanks. Yes it does to me also. Perhaps I should have mentioned that only one bedroom is regularly in use and we usually only operate the lounge air conditioner. The dining room one is only switched on when we have visitors.

2 hours ago, johng said:

5 KW inverter sounds too small to me too.

Seems the forum admin has allowed PDF's to be uploaded again.. great we'll be able to read technical drawings and immigration forms again.

Yes, I was pleasantly surprised that my .pdf was acceptable!

Edited August 30Aug 30 by The Fugitive

13 hours ago, Hummin said:

Personally, with five air conditioners I would go considerably bigger. Probably around 18 panels, roughly 11 kW of solar, a 10 kW inverter and at least 16 kWh of battery. From there the sky is the limit, depending on how much independence from the grid you actually want.

I would also look closely at everything around the system, not only panels, inverter and battery. Proper breakers and safety breakers, surge protection, battery protection, correct cable sizes, and an overhaul of the existing electrical system in the house if needed.

The quote already includes quite a lot of this, including the distribution box, leakage and short circuit protection, battery breaker equipment, surge protection and grounding, which is good.

It is strange, once you first get a solar system you always seem to wish you had more. I oversized pretty much everything myself from the start, except the battery capacity, which I added to later on.

I cannot really comment on the price itself, because that depends a lot on the company doing the installation, factory guarantees, the quality of the components, and what the installer promises in terms of aftersales service.

Many thanks! Most helpful advice.

2 hours ago, motdaeng said:

sorry, no comment on the quotation. i do notice that many people choose a solar system without first carrying out the necessary technical and consumption analysis. unfortunately, some solar companies also seem to consider these checks unnecessary ...

just a few technical thoughts on how i for myself would approach sizing a solar system :

1. analyse the actual electricity consumption:

• annual and monthly kwh

• average daily consumption

• daytime consumption, especially 08:00–17:00

• day vs. night loads

• expected future consumption, e.g. electic car, additional ac, family growth, etc.

2. check the electrical system:

• single- or three-phase connection

• smart meter

3. analyse the installation site:

• panel orientation and tilt

• shading throughout the day/year

• available roof area

• access for cleaning and maintenance

• potential for future expansion

4. define the objective:
   maximum self-consumption, bill reduction, only daytime load coverage, zero export or export to pea, etc

only after these parameters are known should the pv capacity, inverter and battery be sized ...

the goal should be an optimized system based on actual consumption and future requirements ...

OR ....do it like Carl did. :)

PEA_Inverter_list_29-Aug-18.pdf

Testing 123

6 minutes ago, johng said:

PEA_Inverter_list_29-Aug-18.pdf

Testing 123

Thanks!

3 minutes ago, The Fugitive said:

Thanks!

Did I miss DEYE? Speed reading as usual.

5 hours ago, carlyai said:

I also think you need a bigger inverter etc.

You don't mention any brand names for inverter and battery.

Make sure you order reputable inverter and battery/ies.

For the submission of the documents, I heard (can't remember where, think it was my electrician) that for a 5kW system it was B5000, 10kW system B10000, 20kW system B20000. Not sure of any reason behind this, so your charge for this item seems high.

Many thanks!

2 hours ago, motdaeng said:

sorry, no comment on the quotation. i do notice that many people choose a solar system without first carrying out the necessary technical and consumption analysis. unfortunately, some solar companies also seem to consider these checks unnecessary ...

just a few technical thoughts on how i for myself would approach sizing a solar system :

1. analyse the actual electricity consumption:

• annual and monthly kwh

• average daily consumption

• daytime consumption, especially 08:00–17:00

• day vs. night loads

• expected future consumption, e.g. electic car, additional ac, family growth, etc.

2. check the electrical system:

• single- or three-phase connection

• smart meter

3. analyse the installation site:

• panel orientation and tilt

• shading throughout the day/year

• available roof area

• access for cleaning and maintenance

• potential for future expansion

4. define the objective:
   maximum self-consumption, bill reduction, only daytime load coverage, zero export or export to pea, etc

only after these parameters are known should the pv capacity, inverter and battery be sized ...

the goal should be an optimized system based on actual consumption and future requirements ...

Comprehensive advice! Thank you.

2 hours ago, The Fugitive said:

Thanks. Yes it does to me also. Perhaps I should have mentioned that only one bedroom is regularly in use and we usually only operate the lounge air conditioner. The dining room one is only switched on when we have visitors.

I’m not sure what is worse for the air conditioners, constantly switching them on and off or just letting them run 24/7. With enough solar panels, you can also protect your house and belongings by keeping the temperature and humidity more stable, while creating a healthier indoor environment with air cleaners, regular servicing and maintenance of the units.

So if you have enough capacity, why not let a few units run 24/7? New inverter models are also more efficient when they can run steadily at low output instead of repeatedly stopping and starting and having to cool the room down again.

On 8/30/2026 at 10:59 AM, The Fugitive said:

Thanks. Yes it does to me also. Perhaps I should have mentioned that only one bedroom is regularly in use and we usually only operate the lounge air conditioner. The dining room one is only switched on when we have visitors.

Per your usage of A/C above, what is your electric bill for the month from PEA?

On 8/29/2026 at 9:06 PM, The Fugitive said:

Obtained this quote from a local installer. We have a modest three bedroomed single storey house with 3 X 12,000 btu and 2 X 18,000 btu dual inverter air conditioners. No electric vehicle. Panels to be installed upon carport roof. Meter will require moving to the next power pole and the mains will then enter the house from the opposite end. This is included in the quote. Looks good to me but if anyone can spot any errors or omissions I'd be obliged. Thank you most kindly!

Solar Quote (English).pdf

Just had a quote yesterday for a 5kw system which will provide more than enough power for our 2 bedroom, single story house with small dip pool. 2 a/c units but only the main bedroom in regular use. 256,900. (no moving of meter: 10 year warranty on inverter and battery: one year free service warranty by installer.

Have you looked into a TOU meter, this gives cheap electricity during the night, i just got this from google search, i do not use them or have anything do do with them, this and solar together seem a good idea, but if you want to go totally off grid!, i live in Bangkok so it is MEA think it cost about 5000 for the meter

https://capsolar.co.th/en/knowledge/request-tou-meter-thailand-guide

9 minutes ago, howerde said:

Have you looked into a TOU meter, this gives cheap electricity during the night, i just got this from google search, i do not use them or have anything do do with them, this and solar together seem a good idea, but if you want to go totally off grid!, i live in Bangkok so it is MEA think it cost about 5000 for the meter

Not only the night but all weekends and all holidays. We have it combined with solar and it has really worked a treat.

First, keep this in mind: If your monthly electricity bill doesn't exceed 3,000 THB, a solar system will never pay off financially—unless you want one for ideological reasons!

3 hours ago, 241195_1469957797 said:

First, keep this in mind: If your monthly electricity bill doesn't exceed 3,000 THB, a solar system will never pay off financially—unless you want one for ideological reasons!

I agree with you 100%. I asked the question above what his electric bill from PEA is for one month. As the saying goes Do the Math. I have pretty much the same set up at my house as he describes and I would never spend that kind of money for solar and introduce issues of maintenance. I am happy with my 3-phase coming into the house without very little power loss due to storms. To each their own and I do not drive an EV.

7 hours ago, cdulaney said:

Per your usage of A/C above, what is your electric bill for the month from PEA?

Thanks; last bill was; 3,041. Generally varies between 3,000 and 4.000 THB.

3 hours ago, 241195_1469957797 said:

First, keep this in mind: If your monthly electricity bill doesn't exceed 3,000 THB, a solar system will never pay off financially—unless you want one for ideological reasons!

Thanks, makes sense. Mrs and myself are thrifty. Bills approx; 3,000 to 4,000 per month. However, this June I felt the heat and ran bedroom plus lounge and dining room air conditioners continuously. Bill was 6,018 THB. Another factor was we had a short power cut last month that tripped a circuit breaker. That doesn't usually happen. The surge fried three of my eight CCTV camera power supplies. I'm hoping that my solar installation will help guard against that?

It will but you still need lightning protection as well and good earth.

I have lightning protection on my panel feed into the inverter, protection from PEA into the inverter and protection from the inverter feed to the house.

You can get lightning protection now that responds to the initial lightning strike and also helps attenuate any residual.