007 RED

19 hours ago, BritManToo said:

Shame they didn't have a level. Inverter looks sloping to me.

There it's straight now.... just for you ????

 

53 minutes ago, Pink7 said:

There is 2 single serial strings who have its own pw port on inverter. So i will use a dc breaker and dc surge/lightning protector between panels and inverter. AC anti surge/lightning protector i should use for grip power before inverter?

 

Pink

As has pointed out by @Muhendis and @Crossy, it is wise to have an appropriate breakers and surge suppressors located either side and as close to your inverter as practically possible.  As has been mentioned, it is extremely important to only use a DC breaker on the DC side of the inverter and an AC breaker on the AC side of the inverter.  Big flashes and magic smoke are likely to occur if you use an AC breaker on the DC side of the inverter.

 

The breakers enable you to isolate the inverter from DC and AC supplies, so that you can carry out any maintenance on the panels or remove the inverter if necessary.  The surge suppressors are there to protect your investment (inverter) in the event of a surge arising from a nearby lightening strike or problems with you local PEA supply.

 

The photo below which I provided in an earlier post shows my small scale set up with the Sofar GTI inverter in the centre. 

 

The cables coming down from the top left of the picture are the DC +/- feeds from the 4 x 415W (connected in series) solar panels mounted directly above on the roof of the car port.  These cables are connected to the DC breaker and and surge suppressor which are housed in my home made 'safety box' (small empty consumer unit box).  From the DC breaker the +/- cables are then connected to the respective input DC sockets on the inverter. 

 

With your proposed setup you would have two feeds coming from your solar panel array, e.g. PV1 and PV2, each of which should be connected to their own DC breakers and surge suppressors before being connected to the inlet connections on the inverter.

 

The large black plug and cable coming out the bottom right of my inverter is the AC cable which is feeding power generated by the inverter to my house consumer unit.  This cable is initially connected to the AC breaker and suppressor, again in a home made 'safety box' before being connected to the consumer unit in the house.

 

FYI.... Both 'safety boxes' and the inverter have separate earth cables which are connected to the metalwork of the car port.  The metalwork inside the main supports of the car port are buried quite deep " meters plus) into the ground, but I have also connected a 2 meter earth rod buried in the soil to the car port metalwork.  'Belt and braces' approach.

 

I hope this helps with your proposed project.

1 hour ago, Sophon said:

Thank you.

 

One thing I am a little hazy about, are the actual connections on the DC side. From your picture it looks like there are special plugs for plugging into the inverter, rather than the "shove the cable into a hole and tighten a screw" that I am used to on the AC side. The same is probably true for the battery connections, and I have already seen that it's the case when connecting the solar panels.  

 

I am also not clear on what cable sizes I need for a 5 kW system, one of the sellers of inverters on Lazada quoted 4 sq.mm. but is that enough for a sustained energy flow of up to 5 kW? FWIW the finished cables that Global sell does seem to be mostly 4 sq.mm.

 

And, as I have not presently any surge suppressors, what kind of cable sizes do they require? They need to be able to divert large amounts of energy, but obviously only for a very short time.

 

Hopefully, these are things that will become clear with further research. 

You will find that MC4 plugs and sockets are commonly used for connecting the solar panels and as shown in my case the cables from the panels to the DC 'safety box', and the outlet from the DC 'safety box' to the inverter.  The inverter came fitted with the DC input socket and a plug (both MC4).

 

All the panels came with 4mm cables with MC4 plug or socket attached.  I could have used 4mm cable to run from the panels to the DC 'safety box'.  Because of the length between the furthest panel and the DC 'safety box' I decided to use 6mm instead of the normal 4mm in order to reduce any voltage drop. 

 

The MC4 connectors will take a 6mm cable.  You will also find a lot of "how too" videos on Youtube showing how to make an MC4 connection.

 

I would certainly endorse @Crossy comment regarding investing in a good quality crimping tool to ensure that you have a good strong/tight connection.  It will also save you a lot of time fiddling around with pliers if you have a few connections to make.  A good investment so far as I was concerned.

 

FYI.... When I was installing my system, I checked the continuity of all connections with an AVO meter.  During the commissioning of the system I discovered that one of the MC4 connectors at the inverter was getting quite warm.  Close examination showed that I had not crimped the cable in the correct place.  I'm not sure, but if I had not double checked everything I suspect that this could have caused a real problem.

1 hour ago, Encid said:

My questions are related to the power rating (340W or 450W respectively).

 

I understand that this nameplate output wattage is under ideal (laboratory) circumstances, and does not take into account real life diminishing circumstances like dust, bird droppings, cloudy conditions, rain etc... so in sizing a system I would need to apply an efficiency rating... say an average of 2/3 output per day (say an 8 hour period).

 

Does this sound realistic?

 

What is the timeframe for the nameplate output wattage? 1 hour? 8 hours? 24 hours?

@Encid  You are 100% correct when you state that the output rating a solar panel (e.g. 340W or 450W) is determined under ideal (laboratory) conditions.  Basically this is a specific light source shining directly perpendicular onto a given area of photo cells within the panel.  Also, the temperature of the photo cells within the panel is maintained at a constant 25⁰C during the tests.

 

The biggest efficiency loss of solar panels is created by heat generated by the radiated light from the sun.  At mid-day, with the sun overhead, and no haze or clouds it is possible for the temperature of the panels get up to 70 or 80⁰C,.  For every 1⁰C above the laboratory test figure of 25⁰C, the efficiency of the panel will reduce by x%, where x% is the temperature co-efficient of the panel which can be between -0.2% to -0.5% depending upon type of panel and manufacturer.  Obviously the lower the the figure the better.

 

Other solar panel efficiency losses as you indicate can be caused by cloud, haze, dirt etc. which added to the loss cause by heat can be as much as 25%.  It is therefore, generally recommended to build in a potential loss of 25% when calculating the size of a system. 

 

For example, when I designed my small scale system I wanted it to produce a maximum of 7 units per day.   Based upon a 6 hour day, that means the panels need to produce 1.2 kWh.  The panels I choose were rated at 415W, so 4 x 415W should potentially give 1.660 kWh.  But because of a potential loss of 25% in reality they are more likely to produce my desired 1.2 kWh.

 

My small scale system has been running for almost a year now and the monitoring system shows an average daily production of between 6.5 and 7 kWh per day.

 

FYI.... 6 hours is normally used for sun calculations as there is very little power being generated by the panels between sun rise and mid-morning, and mid-afternoon and sun set.

 

I'm not sure what you mean by the timeframe for the nameplate output Wattage.  All I can assume is that if the panel is rated at say 450W, in theory (lab conditions) it should be capable of producing 450W with a given light source.  The 450W will only be produced so long as that specific light source is available to the photo cells of the panel. 

 

The graph below from my monitoring facility shows the output of my system during the day a few weeks ago and it clearly shows dips when the sun was obscured by heavy clouds and rain, hence loss of power.  On this particular day the system only managed to produce about 3.75 kWh.

I hope this helps.

 

@Sophon, As @Crossy has pointed out above, it is wise to have an appropriate breakers and surge suppressors located either side and as close to your inverter as practically possible.  As has been mentioned, it is extremely important to only use a DC breaker on the DC side of the inverter and an AC breaker on the AC side of the inverter.  Big flashes and magic smoke are likely to occur if you use an AC breaker on the DC side of the inverter.

 

The breakers enable you to isolate the inverter from DC and AC supplies, so that you can carry out any maintenance on the panels or remove the inverter if necessary.  The surge suppressors are there to protect your investment (inverter) in the event of a surge arising from a nearby lightening strike or problems with you local PEA supply.

 

The photo below which I provided in an earlier post shows my small scale set up with the Sofar inverter in the centre. 

 

The cables coming down from the top left of the picture are the DC +/- feeds from solar panels which are mounted directly above on the roof of the car port.  These cables are connected to the DC breaker and and surge suppressor which are housed in my home made 'safety box' (small empty consumer unit box).  From the DC breaker the +/- cables are then connected to the respective input DC sockets on the inverter. 

 

The large black plug and cable coming out the bottom right of the inverter is the AC cable which is feeding power generated by the inverter to my house consumer unit.  This cable is initially connected to the AC breaker and suppressor, again in a home made 'safety box' before being connected to the consumer unit in the house.

 

FYI.... Both 'safety boxes' and the inverter have separate earth cables which are connected to the metalwork of the car port.  The metalwork inside the main supports of the car port are buried quite deep " meters plus) into the ground, but I have also connected a 2 meter earth rod buried in the soil to the car port metalwork.  'Belt and braces' approach.

 

Hi @Sophon.  To answer your initial question, yes it is possible for someone with little or no previous experience of solar systems to undertake a DIY installation.

 

A couple of years ago at the beginning of the pandemic ‘lockdown’ I was reading @Crossy post “How about a solar car port on a budget” and this inspired me to consider doing something similar.

 

I openly confess to having no previous experience of solar systems and a fairly basic knowledge of electrical/electronic systems dating back to my days at Coventry Polytechnic some 50 plus years ago.  In fact, I would happily describe myself as a total nerd when it comes to solar systems.  That said, DIY seems to be in my DNA.

 

I have to admit, learning and researching about solar systems was a great experience which helped alleviate the boredom created by ‘self-hibernation’ under the Covid19 restrictions in force at the time.

 

We (my wife and I) had a car port constructed in 2018 on land that we purchased adjacent to our house and this was ideally positioned in so far that one side of the roof was South facing and inclined at about 15^o.  Most importantly it was not shaded during the day, therefore, any solar panels mounted on the roof should (in theory) capture maximum sunlight during the day and would not be seen from the road.

 

From the information obtained from our local PEA, I discovered that our average usage was 275 units per month (approximately 9 units per day).  This info can be obtained by entering a couple of basic details into the PEA ‘s web page https://www.pea.co.th/en/e-Service/Meter-Reading-History .   So based upon this info, I decided to go for a simple grid tied solar system with the intention of reducing our monthly subscription to the local PEA by about 75%, (e.g. from 9 to approximately 7 units/day).

 

As a result, I've put together a small scale solar system comprising 4 x 415W half cut mono solar panels plus a 2kW GTI inverter.  Total cost was 28K THB including stainless steel mounting brackets, cables/connectors and isolator switches.

 

 

 

Note:  4 x415W panels should be capable of producing approximately 1660W under ideal (laboratory) conditions, but in reality such a configuration is more likely to only produce 75% of that due to heat and shading etc.  Therefore, with a 6 hour ‘window’ of decent sunlight a day the panels are more likely to produce about 1245W .  Hence the panels should produce around 7 units per day which meets my original intention of reducing my monthly bill by 75%.

 

It was a real DIY job from beginning to end. 

 

The only physical assistance I had was lifting the panels onto the car port roof. (Don't ask).

 

The system has now been running for 10 months and I’m well on target to recover my initial investment in about 2.5 years.  One forum member suggested that saving just a few Baht a month was ‘penny pinching’.  Well, if you consider the pathetic interest rate that you get from most bank savings accounts, compared to the potential cost saving per year generated by a solar system, solar way out performs the interest rate by far, so I think it’s fair to say solar is in fact a shrewd long term investment.

 

I think that the real motivation for me was that at the age of 74, designing, installing and commissioning a grid tied solar system, albeit a small one, was a great challenge.  Throughout my life, I have always enjoyed the challenges which have been ‘thrown’ at me.  Any long term financial payback, or contribution towards assisting the world to become carbon neutral would just be an incidental bonus so far as I was concerned.

 

A few words of caution

 

Firstly, it should be noted that the electric authorities (MEA or PEA) will not approve a DIY grid tied installation.  According to their policies, all solar system installations which are connected to the grid must be undertaken by one of their approved installers and it must have an electronic meter fitted.  The system must be subsequently certified by one of their engineers.

 

The cost of having a system installed and approved is very overpriced expensive, and the payback for any power which the system might feedback into the grid is very low (approximately half that of the normal purchasing price).

 

Secondly, if you DIY install a grid tied solar system and have a spinning disc type meter any excess power produced by the system can potentially be fed back into the grid and make the disc spin backwards thus reducing the number of units used.  This practice is frowned upon by the electric authorities and if discovered (usually by the meter reader) they (MEA/PEA) will at best replace the meter with an electronic one which prevents ‘spin back’ or at worse they may disconnect the supply and demand that the solar system’ be removed and/or impose a fine.

 

FYI... We know from past records that our meter reader visits on, or about the 15th of each month.  So I've installed a Crossy 'patented'  NO Export Device which is activated prior to the meter reader's visit.  This stops the system exporting any surplus power back into the grid and the meter spinning backwards.  Once the meter reader has been its switched back into Export mode again.

 

The physical switch shown above has now be complemented with an electronic controlled relay device which can be activated by an application on my phone via the internet as seen below.

 

Best of luck with your proposed venture.

11 hours ago, Neeranam said:

I thought the pink card had no electronic thingy. 

4 hours ago, FriendlyFarang said:

The pink ID card has no magnetic strip and no chip, so nothing a card reader could read.

If you are referring to an electronic chip, then your 100% correct.  However, if you have a pink card and look at the reverse (back) side you will see a black strip running horizontally across the top of the card.  This is a magnetic strip which is embedded within the plastic of the card and can be, and in the case of the pink card is, programmed with binary data which can be read by drawing the magnetic strip through card reader.

 

FYI... I have a simple card reader (purchased from Shoppe 1,000 THB) which is connected to my computer. 

A simple programme confirms that the information held on the magnetic strip of my pink card comprises my 13 digit ID number plus the character and 8 numbers engraved in the white block in the bottom left of the reverse of the card.

 

If you look at the reverse side of your bank cards (credit and debit) and even the new Thai QR driving licence they also have the same magnetic strip embedded in them.  Because it it very easy to read and subsequently clone the data held on theses magnetic strips their use by many organisations (banks etc) have been made redundant and replaced by the electronic chip which offers far better security feature.

 

FYI... the card reader used by the cashier at the hospital looks like the one below.  It appears to be a multi function device that can read cards with chip or magnetic strip.  The device also produces a printed receipt slip similar to the one you will get when you use your credit/debit card in store.  The receipt slip has my pink ID number on it.

What I’m about to share with follow forum members is based upon my practical experience and not some hearsay from a friend of a friend.

 

As a couple of members have muted in earlier posts, expats who have a pink card and are legally married to a Thai who is a, or a retired, civil servant can obtain a discount on treatment and medication at their nominated government hospitals.

 

In my case I’ve been married for the past 15 years to a wonderful Thai woman who was (now retired) a civil servant.

 

Shortly after our marriage my good lady was informed by her finance department when she informed them about her change of status (single to married) that she could apparently have me registered against her Social Security number.  It appears that as I was on an extension of permission to stay based upon retirement not working in Thailand, I was eligible to ‘piggyback’ onto benefit which were provided by her SS provisions.

 

At the time she was informed that it was possible to have me register with the Ministry of Finance using my passport number.  However, she was strongly advised that it would be far better for me to obtain a pink card as the 13 digit ID number on the card can more easily be linked into the various ministries computer systems.

 

Based upon that advise we initially obtained the yellow book from our local district office (which was obtained with minimal difficulties).  Once the yellow book had been issued I was able to obtain the infamous pink card which my wife subsequently took to her finance office together with a copy of my passport.  A few weeks latter she was informed that I had been registered against her SS ID and with the Ministry of Finance and that I should contact the admin department of the government hospital that I was registered with and give them my pink card so that they can enter my pink card ID number onto their system which will then link into the Ministry of Finance.

 

Some 3 years ago during a routine eye check-up for glasses it was discovered that I had intraocular hypertension in both eyes and I was advised by the optician to see an ophthalmic consultant.  As a result, my good lady made an appointment for me to see an ophthalmic consultant at Ramathibodi Hospital in Bangkok (government hospital) where I was registered.  The consultant confirmed that the fluid pressure in both eyes was high and if not controlled would lead to glaucoma and potential blindness.  The treatment was simple, eye drops in both eyes’ morning and evening plus check ups every 4 months to make sure that the pressure in both eyes was within acceptable limits.

 

The actual cost of each check up is 750 THB plus 3,500 THB for 4 months’ supply of 2 types of eye drops.  Total cost = 4,250 THB.  However, when I present the invoice to the cashier and hand over my pink card the amount I actually have to pay is reduced to approximately 700 THB.  There appears to be a small discount against the medical service part of the bill and the medication appears to be ‘free’.

 

I note that the cashier swipes my card in a card reader on her desk and always gives me a receipt showing the actual amount and the discounted payment amount.  I note that my pink card ID number is always shown on the receipt.

 

More recently I found it necessary to have cataract operation on both eyes.  The same ophthalmic consultant I have been using at Ramathibodi Hospital advised that the cost would be between 35,000 and 40,000 THB per eye for single vision lens, which I was perfectly happy to self-fund. 

 

The ops were done under local anaesthetic, so I was able to go home shortly after the ops.  To my great surprise, I was only required to pay 10,000 THB for each eye op on presenting my pink card to the cashier.  It appears that that I qualified for a very substantial discount.

 

So, in my case (being married to a Thai civil servant, now retired) and having the pink card has proved a tremendous benefit in more ways than one. 

 

As mentioned at the beginning it may well have been possible for my wife to initially register me using my passport number but having, and using the pink card expedites a discount payment and negates the need to carry my passport with me whenever I go to the hospital.

I renewed my passport late last year through VFS in Bangkok.  When I collected my new passport, they (VFS) handed me a template letter from the British Embassy which I apparently needed to fill in and present to my local immigration office together with both my old and new passports in order to facilitate the transfer of certain stamps from my old passport to the new one.

 

FYI…. The Embassy letter, including the signature of the Vice Consul, was (in my opinion) a very poor quality photocopy produced on cheap (thin) paper.  The embossed Embassy seal was virtually non-existent.

 

I scanned the Embassy letter which VFS had provided and produced a PDF copy of it.  I was then able to fill in the required details using PDF form filler.  I printed the completed PDF copy of the Embassy letter and submitted it to my local immigration office with the original and new passports, plus copies of the relevant pages/stamps from the old passport.

 

The IO never ‘batted an eyelid’, in fact I am fairly sure that she never really took any notice of the Embassy letter whatsoever.  She appeared to be more interested in comparing copies of the stamps/pages that I had provided with those in the old passport.  That said, within a few minutes she had stamped my new passport with 4 stamps and handed both the old and new passports back to me.

 

I have attached a PDF copy of the Embassy letter below should anyone wish to make use of it.

 

Please note the disclaimer at the bottom of the Embassy letter which basically indicates that the letter does not certify anything.

Embassy Letter for Immigration.pdf

Solar is certainly the way forward.  I have a small scale DIY installation on my car port roof comprising 4 x 415W half cut mono panels which feed into a 2kW grid tied inverter.  Total cost 28K BHT.

 

On average my little system is producing 7 units per day which at the current cost of electricity will have paid for its self in approximately 2.5 years.  Obviously any increase in the cost of electricity will mean that payback is quicker.

 

For more info on alternative renewable energy take a look at https://aseannow.com/forum/319-alternativerenewable-energy-forum/

22 hours ago, Will B Good said:

Would it be feasible to run a decent sized fan from a solar cell or even a small aircon unit, just for daytime use?

Re:  Solar Cell run fan.... you might like to take a look at the link below to Roove Solar who have such a beastie.

 

 https://www.facebook.com/commerce/products/พัดลมโซล่าเซลล์-แบบตั้งพื้น-16นิ้ว-25w-5ใบพัด-ช่องเสียบ-usb-แบตเตอรี่ในตัว/5222693214407344/?ref=mini_shop_storefront&referral_code=mini_shop_page_header_cta

 

FYI... The shop is based on the Western outskirts of BKK and they have a presence on Shopee.   I've used them to purchase my solar panels - good service.

 

Hope this helps.

When I was initially considering a small scale DIY grid tied system a couple of years ago one of the first problems I encountered was establishing how many units we (my better half and I) had been using as this was an essential figure needed in order to size our potential system. 

 

We paid the monthly bill automatically from a specific bank account and never really took much notice of the bill which the meter reader pushed into our letter box.  The bills tended to be put in the WPB whenever we opened the box to retrieve letters.

 

So, in order to establish our electrical usage for the past 12 months, my wife and I popped into our local PEA office and asked them if they would be kind enough to provide us with details of our past 12 months usage.  At first we were met with blank looks, but after lots of nice smiles and pleas we were referred to a supervisor who asked lots of questions as to why we would want such information.  We told her a ‘little porky’ in so far that we thought that the bank may have been over charging us and we wanted the information to enable us to check.  She (fell for it) accepted our explanation and a few minutes later produced a nice printout itemising our monthly usage in terms of: - meter reading date and time; current & previous meter readings; number units used; cost.

 

The printout showed that during the previous 12 months we had been using an average of 275 Units per month.  As I said I was looking at a small scale system as our average monthly usage was relatively small.  This figure (275 Units per month) would form the basis for the sizing of my proposed solar panel project. 

 

FYI…. I was subsequently informed by a fellow forum members that I could have obtained the same information by entering a couple of basic details from your bill (CA/Ref. No.1  & PEA No.) into the PEA ‘s web page https://www.pea.co.th/en/e-Service/Meter-Reading-History    This will provide you with data of your monthly usage for the past 2 years ‘You live and learn’.

 

Good luck with your project.