I am totally green regarding household solar power, so bear with me. Talking to so called local "experts", I am told that a solar installation needs to be certified by the PEA, is this true? What are the ramifications of not informing them? Does this apply to all different installations and, if not, what can I install without calling PEA. I am not considering something underhand, I just want to know the correct way foreward before we start seriously looking to source a solar installation. Many thanks for your time. planemad!

You are obligated to register, but very few bother! I choose to do it right away, so Im done with it, and nobody can make any trouble later, and our area starts to get chanote title on the land as well, so better to make sure everything is ok with PEA office.

Did cost me 12k extra but then all the necessary paper work is done by an engineer.

What kind of system are you thinking of?

Generally: -

• If off-grid (no connection to PEA at all) - No need to tell anyone.

• If using an "off-grid hybrid" inverter which cannot grid-sync or export (it can switch to grid or charge the batteries but not supplement the solar) - I wouldn't bother telling them.

• If using an "on-grid hybrid" inverter you should ensure that it's on their list of approved inverters and set it so it doesn't export - Registration is required.

• Similarly with "grid-tie" inverters you should ensure that it's on their list of approved inverters and set it so it doesn't export - Registration is required.

A few panels and a micro-inverter isn't going to attract the blue-meanies.

The old spinning-disk meters will actually run backwards when exporting thus reducing your bill. This is not permitted although the worst punishment is generally a slapped wrist and the installation of a non-reverse meter. I don't recommend doing this now.

Of course, if you want to sell energy you will need a fully approved system and installer and a few reams of paperwork.

Have a chat with your local PEA office they will inform you of their interpretation of the rules which, like everything else here, can be, er "variable".

When we spoke to our office a few years back the manager stated "you are not allowed to spin the meter backwards!!", on our way out he quietly said "don't let the meter reader see it going backwards"

New house build, so new meter and asked when installed if having solar. Yes, not sure if conveyed to main office. If ever required to register at a cost, will simply tell them to cancel & take meter.

17 minutes ago, KhunLA said:

New house build, so new meter and asked when installed if having solar. Yes, not sure if conveyed to main office. If ever required to register at a cost, will simply tell them to cancel & take meter.

Yeah, we are in a similar situation, if they want us to register our system then they can take the meter.

We are currently half way through a one-month stress test - OK UK family are here so all the A/C is on "arctic".

We are burning through about 100kWh per DAY all of which is from the solar! We don't need no stinking grid!

I'll put the graphs on my CarPort thread when they go home on the 17th of April.

2 hours ago, Crossy said:

We are burning through about 100kWh per DAY all of which is from the solar!

I never would have thought we could go over the century mark in consumption.... Never say never.

A house renovation with the workers frequently in/out, stockpile of laundry due to maid's absence and a near empty EV took Apr 3 consumption to 117kWh. Also March brought us the first 2K kWh month for '26. We only cover 70% with solar production.

2 hours ago, Crossy said:

We are burning through about 100kWh per DAY

5 minutes ago, gamb00ler said:

Apr 3 consumption to 117kWh

How many Kwh are your solar systems to handle that load?

Just now, Packer said:

How many Kwh are your solar systems to handle that load?

30kWp of panels.

120kWh of storage.

26kW of inverter.

And I thought our 1MWh per month was a lot 🙄

5 minutes ago, KhunLA said:

And I thought our 1MWh per month was a lot 🙄

I'm just glad I'm not paying PEA for the energy!

I love my UK family very much, but I also love the sight of the taxi tail-lights heading for the airport.

Madam wants to build a guest house for visitors, I see it as a space for more solar!!

2 minutes ago, Crossy said:

I'm just glad I'm not paying PEA for the energy!

I love my UK family very much, but I also love the sight of the taxi tail-lights heading for the airport.

Ditto, as we'll be at ROI at years end, if not counting the extra ESS we didn't need. If not installed and DIY'd it, we'd be there already. Having only 3.5 yrs.

INDEPENDENCE is way too cool 😄

50 minutes ago, Packer said:

How many Kwh are your solar systems to handle that load?

We have 25 450w panels, a 10kW hybrid inverter and 24.6 kWh of batteries. Over the long term solar output covers about 70% of our consumption... and provides plenty of backup when PEA goes down. No A/C on backup of course.

We only have 18 X 540w panels on 8kW hybrid inv w/ 20kWh ESS (2x10). Just 2 of us, and normally use less than 8kWh overnight. Provides 100% of our needs, w/BEVs.

Curious regarding el-energy consumption: What temps are you guys running your ACs?

At what temperature do you feel comfortable (which is not the same as the temp setting on your AC remote)

1 hour ago, mistral53 said:

What temps are you guys running your ACs?

27° C

11 hours ago, mistral53 said:

Curious regarding el-energy consumption: What temps are you guys running your ACs?

At what temperature do you feel comfortable (which is not the same as the temp setting on your AC remote)

Overnight, non producing hours, ~1730 to 0730 @ 27° C +/-

Use between 6-8 kWh overnight. What's running ...

2 frigs, alone use <200w (when out of town)

minimal lighting, doesn't even register (when out of town)

13 BTU AC, cooling bedroom (23m²)

55" TV (100w/hr (7 hrs)

2 laptops

2 air filter (auto (low)

Many thanks for all the replies to my question. I think I better understand what I can legally do and what I cant. The wife has a cousin who is a real downer "you cant do that" "what if?", so I have to proceed with caution. So, the recent and ongoing hot weather brought the topic of Solar to the fore mainly to reduce the A/C consumption and therefore either cut cost or allow prolonged use. We have a small ish house that is 10 years old, we have 3 bedrooms, a large living area, a kitchen and 2 utility/storage rooms. We run 4 A/C units but only use (usually) the master bedroom which is (I think) 18000 Btu which is where she spends quite some time and our monthly electric bill is between 2500 and maybe 4000 Baht depending on the weather so I question the viability of solar but I am open to some advice. May thanks once again. Planemad.

To the OP's original question - it probably depends where you live, PEA could be more or less aggressive in pursuing solar installation code in your neck of the woods. We live in Hua Hin, there are 3 local installers and only one of them does the PEA conform installation/paperwork as a matter of business practice. The others compete on price and are strictly installers - slap panels on the roof, pull in some wires, add the inverter, then run away never to answer their phone again if there is a problem.

Just a wild guess, but I think probably over 80% of solar installations around here are not registered with PEA.

As for your consumption, it is on the low side to write down the investment as smaller systems are not proportionally less expensive - however, your consumption will definitely increase substantially once you have solar - it's human nature, you might even find justification for an EV in there someday. Nevertheless, I would never inhabit a home without solar anymore.

One more thing: Solar installers tend to under-size solar systems - what they don't tell their customers is that in Thailand we don't have good conditions for solar: It's too hot (reduces panel efficiency significantly) and we have long periods with cloudy days that easily knock off 35+% of your max production capacity - never mind when it rains, it goes to zero.

On my AC usage:

My experience has been that if I set my air conditioner to 27°, it does a poor job dehumidifying the room, so I typically set the ACs to 24°, which means depending on the size of the room, temperatures will drop to 27-28°, and as low as 23° (MB).

In my office I have set my AC temperature to 24°, 25° right now I'm away, controlled by WiFi. To add it all up we have 3 refrigerators that run 24/7, the pool pump that runs 6 hours, of course one to two air conditioners stay on 24/7, not the same at all times (LR during the day, MB at night) so our daily consumption is somewhere around 75 kWh, and that leaves us enough headroom for charging our EV cars for local trips.

1 hour ago, mistral53 said:

To the OP's original question - it probably depends where you live, PEA could be more or less aggressive in pursuing solar installation code in your neck of the woods. We live in Hua Hin, there are 3 local installers and only one of them does the PEA conform installation/paperwork as a matter of business practice. The others compete on price and are strictly installers - slap panels on the roof, pull in some wires, add the inverter, then run away never to answer their phone again if there is a problem.

Just a wild guess, but I think probably over 80% of solar installations around here are not registered with PEA.

As for your consumption, it is on the low side to write down the investment as smaller systems are not proportionally less expensive - however, your consumption will definitely increase substantially once you have solar - it's human nature, you might even find justification for an EV in there someday. Nevertheless, I would never inhabit a home without solar anymore.

One more thing: Solar installers tend to under-size solar systems - what they don't tell their customers is that in Thailand we don't have good conditions for solar: It's too hot (reduces panel efficiency significantly) and we have long periods with cloudy days that easily knock off 35+% of your max production capacity - never mind when it rains, it goes to zero.

On my AC usage:

My experience has been that if I set my air conditioner to 27°, it does a poor job dehumidifying the room, so I typically set the ACs to 24°, which means depending on the size of the room, temperatures will drop to 27-28°, and as low as 23° (MB).

In my office I have set my AC temperature to 24°, 25° right now I'm away, controlled by WiFi. To add it all up we have 3 refrigerators that run 24/7, the pool pump that runs 6 hours, of course one to two air conditioners stay on 24/7, not the same at all times (LR during the day, MB at night) so our daily consumption is somewhere around 75 kWh, and that leaves us enough headroom for charging our EV cars for local trips.

I agree totally with your point on Thai installers, they seem by default to assume you are Thai and do not need a/c on most of the day and in the room all night and that you are at work during the day. we are going down the road now, my bills are usually 5000-9000 and i am trying to conserve ie only 1 a/c on inthe house at a time, i am retired so most of the time at home during the day, go out at weekends, but with 7 a/c units 10 fish tanks, koi pond 2 freezers 2 fridges and i need the a/c on all night, when the a/c units have been cleaned at night 27/28 works but after 2-3 months to get the same comfort i have to turn it down to 25/26 and as the 6 month clean comes up it is usually set to 24, after 2weeks still deciding, though here in Bangkok the prices are not cheap from an estabished company

23 hours ago, planemad said:

Many thanks for all the replies to my question. I think I better understand what I can legally do and what I cant. The wife has a cousin who is a real downer "you cant do that" "what if?", so I have to proceed with caution. So, the recent and ongoing hot weather brought the topic of Solar to the fore mainly to reduce the A/C consumption and therefore either cut cost or allow prolonged use. We have a small ish house that is 10 years old, we have 3 bedrooms, a large living area, a kitchen and 2 utility/storage rooms. We run 4 A/C units but only use (usually) the master bedroom which is (I think) 18000 Btu which is where she spends quite some time and our monthly electric bill is between 2500 and maybe 4000 Baht depending on the weather so I question the viability of solar but I am open to some advice. May thanks once again. Planemad.

Thanks for an interesting post . You are not alone when it comes to solar power knowledge , as there are many ex-pats here in the same boat . I guess that the knowledge comes from either from having been an electrician or you get involved when establishing / pricing a solar panel installation .

One of the important factors to me is 1/ the cost 2/ How many years to recover the investment .

200,000 / 400,000 baht is what I have been quoted which I am not prepared to fund .

I made a recent post here where I asked the question about " Plug in solar power " that is popular in Germany and now will be promoted by the UK government . It will come in a package that contains the panels and a microinverter . Literally plug into a domestic house socket and that's it . Of course its off grid and for day time use only . It cannot do what a large installation can achieve but it will certainly reduce your monthly P.E.A. electric bill . The attraction of this system is its low cost but I don't think it is in Thailand yet AFAIK .

BTW , Crossy did reply and comment on my initial post which I was thankful for .

I'm having a hybrid system installed at the moment, no exporting to the grid. The shop doing it is sorting out the PEA paperwork. My understanding is that the requirements have changed recently and now you only need to inform the PEA that you are fitting the system with a simple statement. There is still a charge to be paid.

7 hours ago, alanrchase said:

I'm having a hybrid system installed at the moment, no exporting to the grid. The shop doing it is sorting out the PEA paperwork. My understanding is that the requirements have changed recently and now you only need to inform the PEA that you are fitting the system with a simple statement. There is still a charge to be paid.

If you could find out more, particularly anything official online (even in Thai) that would be most useful.

If you get any documentation, scans with identifying details redacted of course, would also be most welcome.

@Crossy

Apparently they have updated their equipment list, and our Deye Hybrid is now on the list, as are a for more Deye inverters (#137-174):

https://www.mea.or.th/other-services/electricity-producers/product-registration/iiMBnd5kE?fbclid=IwY2xjawRFrKZleHRuA2FlbQIxMABicmlkETFnbEtOWVN5bTF2NktVTm5qc3J0YwZhcHBfaWQQMjIyMDM5MTc4ODIwMDg5MgABHhifGmNdmRCVfXGIxWHRhHHFyNpO8TcmoD9_Qri_i2KiIhjHtFB-lnArqOf1_aem_Klmsq47Q7ncRDimH6zhmEA

Prior list had two each for 1 & 3 phase, and neither hybrids

@KhunLA Could you please post a link to the updated list in the pinned Approved Inverters thread.

45 minutes ago, Crossy said:

If you could find out more, particularly anything official online (even in Thai) that would be most useful.

If you get any documentation, scans with identifying details redacted of course, would also be most welcome.

From PEA’s current pages, self-use solar is still not just ‘do whatever and tell them later.’ PEA still routes non-export systems through the PPIM connection process and still keeps a connection-point inspection step. The process was simplified in 2025, but not removed. On the engineer drawings, I have not seen a current official PEA page translated saying that requirement has been dropped.

Give a shout to these guys, since they register for customers who ask for registration.

https://solarthailand.biz/?fbclid=IwdGRleARFtKZleHRuA2FlbQIxMQBzcnRjBmFwcF9pZA8xNzM4NDc2NDI2NzAzNzAAAR5tBfIYlQJWBM0C2Quc25I6PKffxaFxYJrsJMGb3D0YdMZl4y4Yt3WLOuoyAA_aem_ILPZ1k-9m0cs5Z0Joa7R0g

On 4/9/2026 at 9:38 AM, mistral53 said:

To the OP's original question - it probably depends where you live, PEA could be more or less aggressive in pursuing solar installation code in your neck of the woods. We live in Hua Hin, there are 3 local installers and only one of them does the PEA conform installation/paperwork as a matter of business practice. The others compete on price and are strictly installers - slap panels on the roof, pull in some wires, add the inverter, then run away never to answer their phone again if there is a problem.

Just a wild guess, but I think probably over 80% of solar installations around here are not registered with PEA.

As for your consumption, it is on the low side to write down the investment as smaller systems are not proportionally less expensive - however, your consumption will definitely increase substantially once you have solar - it's human nature, you might even find justification for an EV in there someday. Nevertheless, I would never inhabit a home without solar anymore.

One more thing: Solar installers tend to under-size solar systems - what they don't tell their customers is that in Thailand we don't have good conditions for solar: It's too hot (reduces panel efficiency significantly) and we have long periods with cloudy days that easily knock off 35+% of your max production capacity - never mind when it rains, it goes to zero.

On my AC usage:

My experience has been that if I set my air conditioner to 27°, it does a poor job dehumidifying the room, so I typically set the ACs to 24°, which means depending on the size of the room, temperatures will drop to 27-28°, and as low as 23° (MB).

In my office I have set my AC temperature to 24°, 25° right now I'm away, controlled by WiFi. To add it all up we have 3 refrigerators that run 24/7, the pool pump that runs 6 hours, of course one to two air conditioners stay on 24/7, not the same at all times (LR during the day, MB at night) so our daily consumption is somewhere around 75 kWh, and that leaves us enough headroom for charging our EV cars for local trips.

Could you give some numbers on your config, as I have a consumption that's about the same as yours.

13 hours ago, Peter Crow said:

Could you give some numbers on your config, as I have a consumption that's about the same as yours.

I have 36 panels, for a total of 18.2 kWp, a Deye hybrid low Voltage grid-tied inverter, 31kWh of ESS.

2 x EV are our wild card. I carefully manage to afford PEA billing us for around THB 500 per months, presumably keeps them from raising red flags.

On a really good day, I can get a close to 95 kWh of energy - expect 1/3 less when we get partly cloudy days. Panels are arranged east, west, south and north facing, which is critical to maximize your solar harvesting. Unlike every installers mantra to have mostly south facing panels, logic dictates north facing or flat panels are more beneficial - to wit, during the winter month when south facing panels rock, most of us don't need as much power due to lower AC loads. Conversely, during this time of the year and into the summer, AC loads are at a max, the sun is moving north of us (by April 23, see this excellent source: https://www.timeanddate.com/sun/thailand/hua-hin?month=4&year=2026)

@Bandersnatch has what I consider the ideal panel arrangement for Thailand.

11 minutes ago, mistral53 said:

I carefully manage to afford PEA billing us for around THB 500 per months, presumably keeps them from raising red

Our local PEA doesn't seem to care, as our bill went from 2000+ to near zero, and they haven't questioned it. They do know, meter installer at least, we have solar, as asked and answered. Don't know if he passed the info further up the chain.

Unless we charge the car with wall charger, rare, then our bills are silly low, <27 baht for conx fee, and what ever extreme minimal use their. Used a few kWh overnight when waiting for ESS to be replaced under warranty, and took about 6 months.

We used to run the meter backwards, turning off the solar system a day or so before meter reading day.

We have never told PEA we have solar but when on holiday, I forgot to turn it off meaning meter reading was lower than the previous month.

They came and told me I’m a naughty boy and don’t do it again (that’s all).

We don’t export any more, though if we have rolling blackouts caused by Trump, it might suit them better if we all export.

4 hours ago, mistral53 said:

I have 36 panels, for a total of 18.2 kWp, a Deye hybrid low Voltage grid-tied inverter, 31kWh of ESS.

2 x EV are our wild card. I carefully manage to afford PEA billing us for around THB 500 per months, presumably keeps them from raising red flags.

On a really good day, I can get a close to 95 kWh of energy - expect 1/3 less when we get partly cloudy days. Panels are arranged east, west, south and north facing, which is critical to maximize your solar harvesting. Unlike every installers mantra to have mostly south facing panels, logic dictates north facing or flat panels are more beneficial - to wit, during the winter month when south facing panels rock, most of us don't need as much power due to lower AC loads. Conversely, during this time of the year and into the summer, AC loads are at a max, the sun is moving north of us (by April 23, see this excellent source: https://www.timeanddate.com/sun/thailand/hua-hin?month=4&year=2026)

@Bandersnatch has what I consider the ideal panel arrangement for Thailand.

Thanks very much for your answer, appreciated very much. Was thinking of and array of 40 panels, so you confirm my numbers. The cells will be ground mounted, with a 2 to 2.5 meter elevation. Right now I'd go for Deye Hybrid + BYD storage. I am not intending to hide anything from PEA, but neither do I plan to sell them much of my production for the ridiculous price they offer. I'll size the battery to store whatever is left with 3 or 4 AC units running (about 80000 BTU) during the day. When I came back from a 12 days holiday this Monday it took about 24 hours to evacuate the heat stored in the building, I'll take that into account as well..

One question for those who know: I have seen diagrams of 3phase installations where the battery array is configured as one subset per phase, this would lead to believe that there is the constraint to add batteries 3 by 3 when upgrading capacity and that thorough load balancing is needed to optimize battery usage. Honestly I'd much prefer if the inverter was able to generated tri-phase current from a single set of batteries.