How many solar panels?

[gejohesch]

I hope I'm not abusing the patience of the experts on the subject. But having read a number of articles on the subject online, I'm still very confused. The (numerous) ones relating to situations in the USA, for example, I find rather unhelpful, as I guess the average domestic energy consumption in the USA would be rather more than what we (my wife + myself + occasional friends or relatives staying with us) would use. Which brings me to the point : I don't really know how much we are using! I know, I should check our bills but my wife tells me she has not kept a single one!

 

So, I would consider that we are rather average when it comes to electricity consumption. We are usually 2 persons in the house, running the usual combo of lights, fans, pumps (for the water), AC's not that much (about 50 BTU's maximum at a given time) and only during day time (we never sleep with AC's on), TV a little bit, an electric oven occasionally, a washing machine (rather often) - and I think that's about it! If people stay with us, I would say add another 50 BTU of AC's.

 

That's all day time consumption. At night, it would only be 2 or 3 fans, 1 TV and a few lights.

 

Considering all that, I would see the installation of solar panels aimed at covering our daytime needs only, and we would fall back on the public electricity supply (mains) at night time. I'm saying that because as I understand it : 1) solar panels don't generate anything at night; and 2) some people use a more complex solar system setup including expensive batteries to get power during the night.

 

I would possibly consider installing mono-crystalline panels of 450 W, which I think are about 1m x 2.1m, and cost somewhere around 5-6,000 baht a piece. I can build a platform above our garage where I could line up 6 of them (if we need that many!).

 

I will keep chasing my wife to start keeping her bills, but in the meantime, I would imagine that our situation is rather average and that a number of people already have relevant experience with solar panels in Thailand, and could give me a bit of advice. Thanks in advance!

[BritManToo]

1x 330w panel generates just over 1 unit/day.

1x 450w panel generates 1.3-1.5 units/day.

[Crossy]

You can use the PEA App, to check your billing history for > 6 months ???? 

[McTavish]

Our 12 x 550w panels have produced an average of 20kwh per day which covers 2 pax house and pool, leaving approx 4kwh charged by PEA for overnight use.

 

Had we been *cough* returning output to the grid our best day may have been 41.2kwh 

[eisfeld]

3 minutes ago, Crossy said:

You can use the PEA App, to check your billing history for > 6 months ???? 

You need some info from a bill to get that set up though if I remember correctly. The OP could go to his local PEA office and get the relevant information. Or wait for the next bill ????

[Crossy]

1 minute ago, eisfeld said:

Or wait for the next bill

 

Yeah, the bill has a history of 5-6 months too.

[gejohesch]

On 9/15/2023 at 12:11 PM, McTavish said:

Our 12 x 550w panels have produced an average of 20kwh per day which covers 2 pax house and pool, leaving approx 4kwh charged by PEA for overnight use.

 

Had we been *cough* returning output to the grid our best day may have been 41.2kwh 

I can now come back to this discussion, having checked our consumption over the last 6 months (on last PEA bill). We reached a maximum of 370 units (Kwh?) from end march to end April, which corresponds to the hottest month we had this year, my wife and myself being in our house in Isan. That's 12.3 units per day. Someone said above "1x 450w panel generates 1.3-1.5 units/day", if I take that as 1.4 units /day average, we would need 9 panels of 450 Kwh to cover that consumption.

 

The reason I'm coming back is that I now wonder how much more our total consumption would be if another couple had stayed that whole period in our second house, using AC's etc. It’s easy to just double up, i.e. to table on 25 units a day (2*12.3). And then to count up to 18 panels of 450 Kwh. The problem is:

1)      the costs : all in all with the wiring and connections etc reaching the 100,000 bahts about.

2)     where to install 18 panels. I would need sthg like a 50 sq m surface available somewhere. The best surface we have would be one of the roofs at about 30 sq m. That would only accommodate 30/50 * 18 = 11 panels… let’s say 12 at best which would be 2/3 what I reckoned above to cover peak consumption with full occupation of our 2 houses.

 

So, my question is, what if we install just those 12 panels? At times our consumption would exceed what those 12 panels could deliver, could we get a boost from the PEA public supply to make up for the excess consumption?

 

I know, I will be told to go and ask in HomePro, Global House etc. However, I have very rarely (if at all) met a vendor with a good command of English around where we are. My Thai is OK for day to day usage, but not for a sustained technical discussion ….. and I like to understand what the vendor is telling us (my wife is not technically minded at all). That’s why I’m asking again on the Aseannow site. Thanks for your patience!

[Crossy]

If you go grid-tie or grid-sync hybrid then even one panel and inverter will offset your bill by whatever it generates.

 

If consumption exceeds the solar production your grid will top-up to the actual demand automagically.

 

Are you intending to go "official" or DIY on this installation??

[McTavish]

1 hour ago, gejohesch said:

So, my question is, what if we install just those 12 panels? At times our consumption would exceed what those 12 panels could deliver, could we get a boost from the PEA public supply to make up for the excess consumption?

Whether you install 9 or 12 panels you can always 'buy' excess from PEA for night use, when guests come to stay or if cloud cover reduces solar production.  A 9 panel system and 5kw inverter could suffice.  My system can produce double your consumption and our best solar day in this past month was 41.2kwh.  Adverse weather saw a total of just over 640kwh for the month.

 

The big name stores are very poor at selling anything but the ticketed items staff have been trained to promote so I would not go to them for advice.  BM/Mod, Crossy, is the best person to advise further. 

 

My installer also supplies Isaan, mainly Khon Kaen thru to Ubon Ratchathani.

[gejohesch]

2 hours ago, Crossy said:

If you go grid-tie or grid-sync hybrid then even one panel and inverter will offset your bill by whatever it generates.

 

If consumption exceeds the solar production your grid will top-up to the actual demand automagically.

 

Are you intending to go "official" or DIY on this installation??

Thanks, that's very clear .... and somewhat of a relief (I will not need to go for a full-blown installation then).

 

I will definitely not go DIY for this, I have strictly no know-how in the matter, and I certainly would not trust "local" workers. So "official" I guess, via a well-established supplier in the ampheu or in Khon Kaen.

[gejohesch]

31 minutes ago, McTavish said:

Whether you install 9 or 12 panels you can always 'buy' excess from PEA for night use, when guests come to stay or if cloud cover reduces solar production.  A 9 panel system and 5kw inverter could suffice.  My system can produce double your consumption and our best solar day in this past month was 41.2kwh.  Adverse weather saw a total of just over 640kwh for the month.

 

The big name stores are very poor at selling anything but the ticketed items staff have been trained to promote so I would not go to them for advice.  BM/Mod, Crossy, is the best person to advise further. 

 

My installer also supplies Isaan, mainly Khon Kaen thru to Ubon Ratchathani.

Thanks a lot!

 

"A 9 panel system and 5kw inverter could suffice.  My system can produce double your consumption and our best solar day in this past month was 41.2kwh." I understand that your system is the "9 panel system", right?

 

"The big name stores are very poor at selling anything but the ticketed items staff have been trained to promote so I would not go to them for advice."

That's what I think of them too! Btw, I have that general feeling in Thailand, whether it's asking about cosmetic surgery, insurance policy, electric pump or whatever, I have the odd feeling that "they nearly always try to push sthg to you". Also, I worked a few years in a large Thai company (as an expat advisor) and I often thought that supposed-to-be experts in this country rather often talk big and quickly about maters they have only a basic knowledge of. You get it, my trust level in Thailand is very low.... ????

 

"BM/Mod, Crossy, is the best person to advise further. " Any more advice where to go shopping for the solar panels would be most welcome. I hope I'm not abusing, I'm very thankful for the good comments so far! ????

[eisfeld]

24 minutes ago, gejohesch said:

I will definitely not go DIY for this, I have strictly no know-how in the matter, and I certainly would not trust "local" workers. So "official" I guess, via a well-established supplier in the ampheu or in Khon Kaen.

There is another dimension to private residential solar in Thailand which can be seen as "official" vs "DIY". If you were to follow all the rules you'd have to talk to PEA and apply for the feed-in tariff. That means that when your current energy production is higher than your current consumption you will feed back into the grid and the meter will count that. You will then be paid for this electricity but the catch is that the rate which they pay you is much lower than what you have to pay for their electricity. Opting for this will make them install a new meter that will count count consumption and production seperately. I didn't check recently but a year or two ago it was a bit less than 2THB per kWh vs. the more than 4THB that most people are paying.

 

Now on the other hand if you go rogue and don't tell them then you will keep your old meter and it will just spin backwards, offsetting any prior or future consumption you might have at another time.

 

Maybe easiest to understand via some example: Assume your net consumption on some Monday is 10kWh. On Tuesday you had much higher production than consumption because you were not home so have a net production of 10kWh.

 

Rogue: the net production of 10kWh will spin the meter backwards to offset the 10kWh you consumed on Monday so you end up with no bill averaged over these two days.

 

Official: on Monday you will be billed for 10kWh and on Tuesday you will be paid for 10kWh. Since the payment you get for the 10kWh of production is about half of what you are charged for the consumption, you'll have to pay the equivalent of something like 5kWh. Very rough calculation.

 

And so going rogue will save people a lot more money but there is always the chance that PEA catches you and then either tells you to turn off your solar as it's not approved or in the worst case imposes some charges/fines. The chance of that happening will depend on the area and property. It's very easy to see if the person from PEA comes to read the meter and sees it spinning backwards. Some care, some don't. I've seen property owners turn off their solar on days where the meter is being read to avoid that. But you have to also make sure you don't run all the way to negative e.g. when leaving the house for extended periods.

 

Edited September 21, 2023 by eisfeld

[McTavish]

7 minutes ago, gejohesch said:

Thanks a lot!

 

"A 9 panel system and 5kw inverter could suffice.  My system can produce double your consumption and our best solar day in this past month was 41.2kwh." I understand that your system is the "9 panel system", right?

 

"The big name stores are very poor at selling anything but the ticketed items staff have been trained to promote so I would not go to them for advice."

That's what I think of them too! Btw, I have that general feeling in Thailand, whether it's asking about cosmetic surgery, insurance policy, electric pump or whatever, I have the odd feeling that "they nearly always try to push sthg to you". Also, I worked a few years in a large Thai company (as an expat advisor) and I often thought that supposed-to-be experts in this country rather often talk big and quickly about maters they have only a basic knowledge of. You get it, my trust level in Thailand is very low.... ????

 

"BM/Mod, Crossy, is the best person to advise further. " Any more advice where to go shopping for the solar panels would be most welcome. I hope I'm not abusing, I'm very thankful for the good comments so far! ????

I have 12 x 550w Lingi tier 1 panels - supposedly the best available at the moment from many suppliers.

[motdaeng]

3 hours ago, gejohesch said:

That's 12.3 units per day

perhaps i am overlooking something.

If you wish to "cover" your 24-hour energy needs, you would need to have a hybrid (battery) system.

 

without a hybrid system, you must know your energy consumption from approximately 08:00 to 18:00 in

order to calculate the necessary solar panel capacity ... in the night you have to use PEA.

 

Edited September 21, 2023 by motdaeng

[eisfeld]

6 minutes ago, motdaeng said:

perhaps i am overlooking something.

If you wish to "cover" your 24-hour energy needs, you would need to have a hybrid (battery) system.

 

without a hybrid system, you must know your energy consumption from approximately 08:00 to 18:00 in

order to calculate the necessary solar panel capacity ... in the night you have to use PEA.

 

Only if going for the official PEA feed-in tariff which counts those seperately. If going rogue as I explained in my last post your production during the day will offset consumption in the night because the meter can spin backwards. Assuming that sometimes there is more production than consumption of course. If that's never the case then there'd be no difference.

Edited September 21, 2023 by eisfeld

[Hummin]

Also interested 

 

We use 400 units a month, sometimes more, and mostly air-condition for gym in day time, and two air-condition a night, sometimes 3 for a few hours. Our 13500 bpu running from 7 in the evening to 5 in the morning.

 

How many panels and how big battery pack

[gejohesch]

55 minutes ago, eisfeld said:

There is another dimension to private residential solar in Thailand which can be seen as "official" vs "DIY". If you were to follow all the rules you'd have to talk to PEA and apply for the feed-in tariff. That means that when your current energy production is higher than your current consumption you will feed back into the grid and the meter will count that. You will then be paid for this electricity but the catch is that the rate which they pay you is much lower than what you have to pay for their electricity. Opting for this will make them install a new meter that will count count consumption and production seperately. I didn't check recently but a year or two ago it was a bit less than 2THB per kWh vs. the more than 4THB that most people are paying.

 

Now on the other hand if you go rogue and don't tell them then you will keep your old meter and it will just spin backwards, offsetting any prior or future consumption you might have at another time.

 

Maybe easiest to understand via some example: Assume your net consumption on some Monday is 10kWh. On Tuesday you had much higher production than consumption because you were not home so have a net production of 10kWh.

 

Rogue: the net production of 10kWh will spin the meter backwards to offset the 10kWh you consumed on Monday so you end up with no bill averaged over these two days.

 

Official: on Monday you will be billed for 10kWh and on Tuesday you will be paid for 10kWh. Since the payment you get for the 10kWh of production is about half of what you are charged for the consumption, you'll have to pay the equivalent of something like 5kWh. Very rough calculation.

 

And so going rogue will save people a lot more money but there is always the chance that PEA catches you and then either tells you to turn off your solar as it's not approved or in the worst case imposes some charges/fines. The chance of that happening will depend on the area and property. It's very easy to see if the person from PEA comes to read the meter and sees it spinning backwards. Some care, some don't. I've seen property owners turn off their solar on days where the meter is being read to avoid that. But you have to also make sure you don't run all the way to negative e.g. when leaving the house for extended periods.

 

Very interesting, thanks! Need to think a bit on that one, but a priori, knowing that we have long absence periods (traveling abroad sometimes for 2-3 months), it sounds like we would better go "official".

[gejohesch]

35 minutes ago, motdaeng said:

perhaps i am overlooking something.

If you wish to "cover" your 24-hour energy needs, you would need to have a hybrid (battery) system.

 

without a hybrid system, you must know your energy consumption from approximately 08:00 to 18:00 in

order to calculate the necessary solar panel capacity ... in the night you have to use PEA.

 

Yes, absolutely right, and thanks for bringing this up. I was already thinking a bit about it..... So, our daytime consumption has indeed to be less than the 12.3 units quoted earlier, and I would have to revise the estimated number of panels down. But how really are we going to know what we consume during daytime???

[motdaeng]

14 hours ago, gejohesch said:

But how really are we going to know what we consume during daytime???

try to do meter readings at 08:00 and 18:00 on a few hot days. that will give you the approximate daily usage.

 

an other point to consider:

some forum members have already mentioned, with PEA bills over approximate 48k thb per year,

a correct sized solar system starts to be an economical good investment (if not a DIY / hobby project).

 

Edited September 22, 2023 by motdaeng
text DIY

[gejohesch]

8 hours ago, motdaeng said:

try to do meter readings at 08:00 and 18:00 on a few hot days. that will give you the approximate daily usage.

 

an other point to consider:

some forum members have already mentioned, with PEA bills over approximate 48k thb per year,

a correct sized solar system starts to be an economical good investment (if not a DIY / hobby project).

 

Thanks, good idea (reading the meter at different times etc)!

 

Now, that statement about the "sweet spot" being 4-5k thb per month and a 6 kw installation" : I wonder. I cannot see ourselves going over 2-2.5 k thb/month (we don't use AC the whole day through). I would imagine an installation of 3kw would then be economical just as well - meaning 6 or 7 panels.

[eisfeld]

14 minutes ago, gejohesch said:

Thanks, good idea (reading the meter at different times etc)!

 

Now, that statement about the "sweet spot" being 4-5k thb per month and a 6 kw installation" : I wonder. I cannot see ourselves going over 2-2.5 k thb/month (we don't use AC the whole day through). I would imagine an installation of 3kw would then be economical just as well - meaning 6 or 7 panels.

It depends on the prices for install and inverter. Price per Watt in terms of panels is the same if you buy 6 or 10. But the price per W can be quite different for 3kW or 6kW. Sometimes it makes sense to buy the bigger one just in case you want to add more panels later. There are also efficiency curves. A 6kW inverter operating at 5kW will be more efficient than a 3kW inverter operating at 3kW. So better make two or three potential scenarios and compare them. If you were to register with PEA for the feed-in tariff it might even makes sense to put as much as reasonably possible. It'll take longer to brake even but it will eventually and once you cross that you might get paid every month instead of reducing the bill to close to zero.

[motdaeng]

@eisfeld, you've made some excellent points, thank you.

 

the overall cost of a registered "grid feed" solar project is significantly higher 

due to the necessary parameters and requirements and it will take it's time. 

 

if i remember correctly, one member chose this route and has been waiting 

for around 2 years for a digital meter just for to start exporting into the grid ...!

 

do we have a member who can officially export to the grid?

 

[gejohesch]

On 9/23/2023 at 1:42 AM, motdaeng said:

@eisfeld, you've made some excellent points, thank you.

 

the overall cost of a registered "grid feed" solar project is significantly higher 

due to the necessary parameters and requirements and it will take it's time. 

 

if i remember correctly, one member chose this route and has been waiting 

for around 2 years for a digital meter just for to start exporting into the grid ...!

 

do we have a member who can officially export to the grid?

 

Coming back to this. No one replied to your question yet (last line).... ???? Meanwhile, I went with my wife  to the local PEA office and discussed the solar options with an advisor. As it turns out, there are indeed a number of options:

a) 3, 5, 10, 15 and 20 KW;

b) 1P or 3P 51 or 3 phase): 3KW is only a 1P option. I'm pretty certain what we have is a 1P (1 phase) installation at home as we are (so far) small domestic users. 10, 15 and 20 KW are only 3P - these probably target large scale users (industrial, shops).

c) Standard or Premium: Standard comes with a String Inverter whereas Premium also has a "Optimiser" and a Micro-Inverter.

 

Now, it's clear that we would either go for 1 or 3 KW, and 1P (still need to plan for additional AC's etc). I'm not clear however about the prices quoted by PEA. OK, they include an entire package (installation, maintenance) but they vary between 131,000 and 269,000 THB (3KW Standard to 5KW Premium). This raises 2 questions:

- is the additional 20,000 to 40,000 THB to go from Standard to Premium worth it? I'm asking because I have no idea what benefits we would get with Premium (not an expert!).

- are the PEA package prices, as mentioned, not a bit over the top ? Without going to boring details here, it seems that the panels on sale in HomePro or Global House plus the inverter would roughly sum up to less than 100,000 THB for a 5 KW installation. OK, there would be extras to pay for wiring etc + installation.... I will eventually get deeper into the matter, but I wonder if anyone on this forum has relevant experience and comments.....

[KhunLA]

50 minutes ago, gejohesch said:

Coming back to this. No one replied to your question yet (last line).... ???? Meanwhile, I went with my wife  to the local PEA office and discussed the solar options with an advisor. As it turns out, there are indeed a number of options:

a) 3, 5, 10, 15 and 20 KW;

b) 1P or 3P 51 or 3 phase): 3KW is only a 1P option. I'm pretty certain what we have is a 1P (1 phase) installation at home as we are (so far) small domestic users. 10, 15 and 20 KW are only 3P - these probably target large scale users (industrial, shops).

c) Standard or Premium: Standard comes with a String Inverter whereas Premium also has a "Optimiser" and a Micro-Inverter.

 

Now, it's clear that we would either go for 1 or 3 KW, and 1P (still need to plan for additional AC's etc). I'm not clear however about the prices quoted by PEA. OK, they include an entire package (installation, maintenance) but they vary between 131,000 and 269,000 THB (3KW Standard to 5KW Premium). This raises 2 questions:

- is the additional 20,000 to 40,000 THB to go from Standard to Premium worth it? I'm asking because I have no idea what benefits we would get with Premium (not an expert!).

- are the PEA package prices, as mentioned, not a bit over the top ? Without going to boring details here, it seems that the panels on sale in HomePro or Global House plus the inverter would roughly sum up to less than 100,000 THB for a 5 KW installation. OK, there would be extras to pay for wiring etc + installation.... I will eventually get deeper into the matter, but I wonder if anyone on this forum has relevant experience and comments.....

Curious, does that include them setting up buy back plan for your excess to them.  If so, did they state how much they pay you per kWh?

 

Guessing they are not hybrid inverters & no batteries involved.  When you state maintenance (virtual none needed), does that mean a life long warranty ?

[eisfeld]

1 hour ago, gejohesch said:

a) 3, 5, 10, 15 and 20 KW;

b) 1P or 3P 51 or 3 phase): 3KW is only a 1P option. I'm pretty certain what we have is a 1P (1 phase) installation at home as we are (so far) small domestic users. 10, 15 and 20 KW are only 3P - these probably target large scale users (industrial, shops).

c) Standard or Premium: Standard comes with a String Inverter whereas Premium also has a "Optimiser" and a Micro-Inverter.

Those are just recommended packages by installers that partner with PEA to get sales through them. You can have 5kW, 10kW etc. on single phase no problem. You do not have to use the PEA sponsoring installers afaik. 1kW is a joke and probably would take a super long time to recover the costs unless you go ghetto style super cheap components from the lazada special items bin installed by somchai the village "electrician" ????

 

A typical residential house should be able to get 10-20kW on the roof. Wouldn't bother installing anything under 5kW if you go feed-in as the cost per watt will be much higher with the smaller packages. Do you have the prices for each package at hand? Would be good if you posted those then.

 

1 hour ago, gejohesch said:

- is the additional 20,000 to 40,000 THB to go from Standard to Premium worth it? I'm asking because I have no idea what benefits we would get with Premium (not an expert!).

If it's just micro-inverter and optimizer as the difference then that's a clear no. Just go for one central string inverter. Less hassle and the efficiency wont be that different for you to warrant that price increase.

 

 

1 hour ago, gejohesch said:

- are the PEA package prices, as mentioned, not a bit over the top ? Without going to boring details here, it seems that the panels on sale in HomePro or Global House plus the inverter would roughly sum up to less than 100,000 THB for a 5 KW installation. OK, there would be extras to pay for wiring etc + installation....

Most likely. As I mentioned those PEA suggested ones are from companies that have a deal with PEA to get sales leads. 270k for 5kW is ridicolous. As you said for 5kW you should arrive at much less than 100k. A 550W panel goes for less than 5k, a 5kW inverter probably something like 25k so with 10 panels you're at less than 75k. Add a bit for cabling, mounting and this and that. Add installation and profit margin etc. Make it a bit more than 100k THB. Wouldn't pay more than 120k. Depends on the components and installer quality.

[TimeMachine]

On 9/15/2023 at 8:57 PM, gejohesch said:

I hope I'm not abusing the patience of the experts on the subject. But having read a number of articles on the subject online, I'm still very confused. The (numerous) ones relating to situations in the USA, for example, I find rather unhelpful, as I guess the average domestic energy consumption in the USA would be rather more than what we (my wife + myself + occasional friends or relatives staying with us) would use. Which brings me to the point : I don't really know how much we are using! I know, I should check our bills but my wife tells me she has not kept a single one!

 

So, I would consider that we are rather average when it comes to electricity consumption. We are usually 2 persons in the house, running the usual combo of lights, fans, pumps (for the water), AC's not that much (about 50 BTU's maximum at a given time) and only during day time (we never sleep with AC's on), TV a little bit, an electric oven occasionally, a washing machine (rather often) - and I think that's about it! If people stay with us, I would say add another 50 BTU of AC's.

 

That's all day time consumption. At night, it would only be 2 or 3 fans, 1 TV and a few lights.

 

Considering all that, I would see the installation of solar panels aimed at covering our daytime needs only, and we would fall back on the public electricity supply (mains) at night time. I'm saying that because as I understand it : 1) solar panels don't generate anything at night; and 2) some people use a more complex solar system setup including expensive batteries to get power during the night.

 

I would possibly consider installing mono-crystalline panels of 450 W, which I think are about 1m x 2.1m, and cost somewhere around 5-6,000 baht a piece. I can build a platform above our garage where I could line up 6 of them (if we need that many!).

 

I will keep chasing my wife to start keeping her bills, but in the meantime, I would imagine that our situation is rather average and that a number of people already have relevant experience with solar panels in Thailand, and could give me a bit of advice. Thanks in advance!

One of the main factors to know first are you going grid tied . If so you need to know how much you get for feeding in. This will tell you if it's worthwhile going overboard on panels or just matching consumption. 

[Danderman123]

On 9/15/2023 at 3:57 AM, gejohesch said:

I hope I'm not abusing the patience of the experts on the subject. But having read a number of articles on the subject online, I'm still very confused. The (numerous) ones relating to situations in the USA, for example, I find rather unhelpful, as I guess the average domestic energy consumption in the USA would be rather more than what we (my wife + myself + occasional friends or relatives staying with us) would use. Which brings me to the point : I don't really know how much we are using! I know, I should check our bills but my wife tells me she has not kept a single one!

 

So, I would consider that we are rather average when it comes to electricity consumption. We are usually 2 persons in the house, running the usual combo of lights, fans, pumps (for the water), AC's not that much (about 50 BTU's maximum at a given time) and only during day time (we never sleep with AC's on), TV a little bit, an electric oven occasionally, a washing machine (rather often) - and I think that's about it! If people stay with us, I would say add another 50 BTU of AC's.

 

That's all day time consumption. At night, it would only be 2 or 3 fans, 1 TV and a few lights.

 

Considering all that, I would see the installation of solar panels aimed at covering our daytime needs only, and we would fall back on the public electricity supply (mains) at night time. I'm saying that because as I understand it : 1) solar panels don't generate anything at night; and 2) some people use a more complex solar system setup including expensive batteries to get power during the night.

 

I would possibly consider installing mono-crystalline panels of 450 W, which I think are about 1m x 2.1m, and cost somewhere around 5-6,000 baht a piece. I can build a platform above our garage where I could line up 6 of them (if we need that many!).

 

I will keep chasing my wife to start keeping her bills, but in the meantime, I would imagine that our situation is rather average and that a number of people already have relevant experience with solar panels in Thailand, and could give me a bit of advice. Thanks in advance!

Without knowing all the environmental factors, it's hard to know:

 

Shade from nearby trees

Angle & orientation of your roof

Working voltage of your system

Cable size

 

My advice is to design your system so that more panels could be added later. Then install the number you think is adequate.

 

[moogradod]

We might in the future think about Solar and since we live in the country of good customer service I would like to have everything out of one hand.

 

I suspect that the planning has an optimum where the ROI is greatest. Now this depends of course on many parameters, but the only thing I would like to tell any prospective Solar provider is how long and when we use which device. I wont even tell him the power consumption. He can find out by himself.

 

He should then plan the optimum system with the said optimum in mind (for him to find out where that is).

 

We live in Chonburi. Any idea where I could find a specialist company (A Solar ?, Solar Power ?, Residential Home (nearest to us) ?) that is professional enough to be able to fulfill this task ?

 

I am aware that this would cost a bit more than a DIY.

 

We then have to talk to PEA as well since we are told that our power consumption is not sufficient with only one phase - we would need 3 phase. I would like that PEA explains me why - we did not even move everything into the new house. So currently we have a brown out if we operate some devices together. The only "big" thing is our 36000 BTU aircon for the living room and we have 2 water pumps with 1.5hp each which run very occasionally. But my name is not Watson so I need a professional Sherlock (maybe with the help of PEA).

[gejohesch]

12 hours ago, KhunLA said:

Curious, does that include them setting up buy back plan for your excess to them.  If so, did they state how much they pay you per kWh?

 

Guessing they are not hybrid inverters & no batteries involved.  When you state maintenance (virtual none needed), does that mean a life long warranty ?

Indeed, I forgot to say, that includes a contract (for 10 years if I remember right) to buy back excess electricity at 2.2 THB / Kwh. I guess that's what is meant by "grid feed" contract.

 

Whenever we need extra power (when solar generated not sufficient), we would buy at the standard rate. I checked, the average we paid over the last 17 months was around 4 THB/Kwh, but that would possibly increase a bit depending on how much we have to "import" (re. PEA price scale).

 

The packages I mentioned do not include batteries. We are not big users at night. 

 

I cannot remember the length of the guarantee , I'm not sure that was for that long as 10 years. Reason I'm a bit vague is that I considered that visit to the PEA office as a "first contact". We are not going to decide for any installation until some time next year. We plan to get a few extra AC's installed first and then watch for what our consumption becomes, then review the calculations.

[gejohesch]

12 hours ago, eisfeld said:

Those are just recommended packages by installers that partner with PEA to get sales through them. You can have 5kW, 10kW etc. on single phase no problem. You do not have to use the PEA sponsoring installers afaik. 1kW is a joke and probably would take a super long time to recover the costs unless you go ghetto style super cheap components from the lazada special items bin installed by somchai the village "electrician" ????

 

A typical residential house should be able to get 10-20kW on the roof. Wouldn't bother installing anything under 5kW if you go feed-in as the cost per watt will be much higher with the smaller packages. Do you have the prices for each package at hand? Would be good if you posted those then.

 

If it's just micro-inverter and optimizer as the difference then that's a clear no. Just go for one central string inverter. Less hassle and the efficiency wont be that different for you to warrant that price increase.

 

 

Most likely. As I mentioned those PEA suggested ones are from companies that have a deal with PEA to get sales leads. 270k for 5kW is ridicolous. As you said for 5kW you should arrive at much less than 100k. A 550W panel goes for less than 5k, a 5kW inverter probably something like 25k so with 10 panels you're at less than 75k. Add a bit for cabling, mounting and this and that. Add installation and profit margin etc. Make it a bit more than 100k THB. Wouldn't pay more than 120k. Depends on the components and installer quality.

I'll come back to all these comments, takes me a bit of time to get my thoughts together! ????