007 RED

A very crafty move, appointing herself as Culture Minister.  Why ?

Because if the Constitutional Court decides that there is a case to answer regarding her phone call to Hun Sen, and they decide to temporarily remove her as PM, she can still cling onto her post in the cabinet.

17 hours ago, motdaeng said:

 

based on your data, a 2.32 kw peak system generates an average of 11.94 kw per day, which seems too high and not very realistic to me ... (i would say is more about 8-9 kw/day)

 

your calculation assumes that every watt produced is fully used, which is quite unlikely – unless you're running a few air conditioners 24/7 ... (but in that case, the system would probably be undersized anyway).

 

maybe some other forum members with DIY setups can share their real-world ROI numbers ... i think if someone can do it an ROI in about  5 yeas, that would be nice ... (but not 15 months or less) ...

Yep, its possible but dependent upon how much solar you install, and if using an ESS, or not.

I installed a small scale grid tied system during the Covid era, and it paid for itself in 2.25 years.  I subsequently added a couple more panels so that I could run the system without feeding back to the grid and on average the system provides us with 75% of our electrical needs.  Our PEA bills are about 200 THB/month. which accounts for our night time use.

Not me this time, but a warning about ensuring that your carport (or roof) can take the weight of your solar system.

https://youtu.be/Ck7c4w9slXU

OUCH !!!!!!

46 minutes ago, Crossy said:

Yes, you need a second CT.

 

Yes, they can sit next to one another without interference. We were running like this (with the CTs less than an inch apart on the cable) for some months and everything worked just fine.

 

Based upon Crossy's Theorem™ which states "You can never have too much solar", and assuming space and budget allow, I'd go for 6 panels and a 3kW inverter. You will start generating earlier and keep generating later.

Thanks... I thought that would be the answer.  Not a problem.

As much as l would like to have more panels, the space on the washroom roof will only allow 4 panels.  I might up the size though.

Current System:

Sofar 3kW grid tied inverter connected in series to 6 x 415W panels which are facing South on the carport roof. 

Historical daily use is approximately 10 units per day, comprising 7 units during the day and 3 units at night. 

System provides 85% (plus) of our electricity needs during the day when in export mode, and approximately 40% during the day when in no export mode.

The system logs clearly indicate that we tend to use most units during the early part of the morning particularly when my better half does the washing (or at least the machine does).

Proposal:

Add a second system comprising a 2kW grid tied inverter connected in series to 4 x 415W solar panels which will be mounted on top of the washing room roof which faces East and gets good sunlight during the early part of the morning.  Both inverters will be located quite some distance apart from each other.

My hope is to have the two GTI systems, both constantly in no export mode (so that the meter never runs backwards), and provides sufficient power to meet our daytime needs, particularly during the early part of the morning when the washing machine is working.

Questions:

The existing GTI is connected to a CT which is located on the incoming Live supply from the pole to the house.  A simple on/off light switch connected in series between the CT and the inverter allows me to switch between export and no export modes, as required.

Q1.  Do I need a separate CT for the second GTI, or can I connect the existing CT to both inverters?

Q2.  If the answer to the above is that I need a separate CT for each GTI, can they be located next to one another, or do they have to be physical separated from each other in order to avoid any undue influence from each other?

02 Aug 25 @ 17:00 Just topped up my Elder card at Lak Song. Cashier took my THB and loaded my card. No mention that card is only for Thais or any other restrictions.

I would suggest that for the opening ceremony parade, the women all wear Tuk Tuk costumes (as per the Miss Universe Contest a few years back photo below).

The men could wear motorcycle suits.  When the march out, and around the stadium, the TTs and m/c should weave in and around each other, just like they do in BBK traffic.

Now that would be a real display of Thai culture 😊

I know it’s been a long time since this topic was discussed.

Did anyone manage to resolve the issue of CT ‘ghosting’ in the No Export mode on their Sofar inverter(s)?

The reason for asking is that it appears that the software in my Sofar 2.2kW inverter has somehow been recently updated – not by me I might add.

I noticed this recently when looking at the LC Display.  The initial reading used to indicate “NORMAL” and ‘XXX’ Watts.  It now shows “DERATING” and ‘XXX’ Watts.

When in the No Export mode, with the inverter’s Reflux setting (#17) set to zero, the online monitoring facility is showing the CT is now sending power going back towards the grid.  It has never done this before to the best of my knowledge.

Most of the time this back feed (in the No Export mode) is 10W which has the effect of almost stopping the disc meter spinning backwards, but not totally.  The disc appears index backwards very, very slowly.

However, at times the back feed to the grid is substantial e.g. 60W, as shown in the screen shot from the monitoring graph below (taken today).  The disc movement (backwards) is very noticeable, albeit slow.  Not something that I want the meter reader, or any other PEA employee, to see.

Any advice/assistance would be most welcome.

Regards

007 Retired Extremely Dangerous

2 hours ago, CharlesHolzhauer said:

Many thanks for this very useful information. I had no idea that the panels are sensitive to heat - thanks again.

It should be borne in mind that the panel’s rating (e.g. 330W) has been determined under ideal laboratory controlled conditions with a specific light source being directly perpendicular to the panel photocells, and the temperature of the panel being maintained at 25^oC. 

Unfortunately, ideal conditions rarely exist in the big bad world and the rating figures provided by the panel’s manufacturer may well be much higher than is achievable in a ‘real world’.  The losses in the panel's efficiency are attributed to the following factors.

Firstly as you will appreciate the sun is constantly moving throughout the day from East to West, and depending upon the time of the year it may be closer to, or further away from, the Southern horizon at any given time of the day.  As a result, it highly unlikely that the sun’s rays will be hitting the photocells within the panel(s) perpendicularly for much time during the day unless your panels are mounted on a very expensive tracking system.  As a consequence, the panels will lose some of their potential output efficiency.

Secondly, solar panels can get quite hot from the heat which is radiated from the sun which can make the temperature of the panels raise to as much as 70^oC or 80^oC.   Unfortunately, the hotter the panels become the greater the loss of the panel’s potential efficiency.  The panel's manufacturers specification should indicate % loss for each 1^oC above the the standard test temperature of 25^oC.

FYI..... Below is a reading which I took with a basic handheld electronic thermometer of my panels at mid-day on a good sunny day.  Ambient temperature was 32^oC  Admittedly not totally scientifically accurate, but it makes the point.  The panels were certainly far too hot to touch.

Thirdly, reductions in the panel’s efficiency will occur due to shading caused by buildings, trees, clouds/haze or dirt/dust accumulating on the panel and blocking the sun’s rays from reaching the panel’s photocells.

Apparently, it may be reasonably assumed that a system might lose as much as 25% of its efficiency due to a combination of the above mentioned problems.

Hence, assuming that 12 x 330W panels should in theory produce almost 4,000W, in practice (assuming a 25% loss) they are more likely to produce just 3,000W on a sunny day, at mid-day.

Once again, good luck with your proposed project.

@CharlesHolzhauer Welcome to the wonderful world of Solar.

When I did my sizing research (approximately 4 years ago) I was not aware of the monitoring devices as suggested by @Bandersnatch above.   I used two methods to give a reasonable estimate of much power we were using, namely:-

1. Log into our PEA online account, insert some basic account details found on our bill, and it returns basic information on number of units used per month for the past 12 months.  By simply dividing the number of days in each month you will have a reasonable indication on your daily use.  As @KunLA has indicated above, your monthly PEA bill also provides basic consumption details for the past 6 months.
    
2. Take a meter reading at approximately 6am, and then another at 6pm.  Do this over a month, or longer, if possible.  This will give you a reasonable indication of usage during daylight hours and at night.  This is particularly useful (night time usage) if you are considering installing a hybrid system with an Electrical Storage System (ESS).

The above methods will give you a reasonable ‘ballpark’ figure of the number of units used which can then be used for sizing your proposed system.

Regarding the number and size of solar panels you will need, please be mindful that the panels can can get very hot as a result of radiated heat from the sun, this can result in the panels loosing as much as 25% of their rated output.  For example:  6 x 415W panels in theory should produce approximately 2.4kWh when the sun is directly above the panels, but because of the heat they are more likely to only produce around 1.8kWh.  So you may need to factor in more panels to cater for heat loss.

Best of luck with your proposed project.

1 hour ago, Crossy said:

@007 RED how are you doing on the recovery front?

 

I went to the hospital last week for a follow up check up.  Must have had about 20 x-rays on my ankle and chest.  God, its a wonder that I'm not glowing in the dark.  Saying that, maybe a new topic - Alternative Energy = Nuclear Power 

Thankfully the ankle is on the mend.  They've taken the cast off and given me a 'Beckham Boot' as shown below.  The joy is that I can take it off to have a shower, and also at night to sleep, but I must wear it whenever I need to put weight on that leg.   

The consultant said that I need to keep wearing the boot for at least another month until the ankle bones have fully knitted.  He advised that if they become displaced, I will likely need surgery to have metal plates and screws inserted to hold the bones in place.  More expense that I will definitely try and avoid. 

The collapsed lung appears to be functioning OK now and my blood oxygen saturation levels are almost back to normal levels.

The fractured ribs are still giving me a lot of grief.  The Doc said that given my age (77) they may well take several months to heal because they are continuously flexing every time I breath in/out.  In the mean time its a case of popping the meds to keep the 'discomfort' under control.

I'm still uncertain as to exactly what happened.  All I can recall was that having made sure all the cables were tucked well under the solar panels, I was making my way back to the ladder to come down when my foot slipped.  The next thing that I remember was laying on the carport floor, unable to move, feeling totally numb and having difficulty breathing.  My better half, who was in the house, heard the crash and ran out to the carport to see what had happened and phoned for the ambulance.  The next thing I remember was being strapped onto a backboard and transported to hospital.  The rest is history.

I just thank my lucky stars that I didn't land head first.  From that height the outcome would most likely have been fatal.  A sobering safety lesson learned and I'm extremely grateful to my wonderful wife for taking so much care of me. 

On 3/7/2024 at 5:22 PM, Lacessit said:

IMO the ladies like an ATM which is open all hours.

I like to think that my better half doesn't think of me as being a 24 x 7 ATM 

On 3/7/2024 at 11:16 AM, Crossy said:

@007 RED didn't realise you'd managed to damage your roof!

 

Is the new ventilation hole now fixed?

 

On 3/7/2024 at 11:54 AM, 007 RED said:

Yes... Local handyman did the repair for a couple of beers.  No way could l do it with a cast on my leg.  Apart from that, my better half has banned me from going up there until l get a walkway put up there.

I've just discovered that the local handyman who repaired the 'ventilation hole' in the carport roof appears to have spilt some silicon sealant onto the glass of 2 of the solar panels.

I assume that he had to remove the mounting screws which hold the panel bridge mounts in order to fit the replacement cement tiles and was using the silicon under the 'feet' of the solar panel mounting bridges to prevent water ingress under the feet.

I've not been up onto the carport roof to take a closer look, as I'm currently banned from undertaking such exploits by my better half, but from what I can see from the 2nd floor balcony which overlooks the carport roof, there are an number of largish globules and smears on the panel's glass.

According to the system's monitoring facility the panels appear to be working OK with no noticeable degradation in power production. 

My question:  Once I'm allowed to get up onto the carport roof, is it safe to remove the silicon from the glass using a non-metallic scraper? 

3 hours ago, ThaiFig said:

 With Tier 1 panels, I figure there is at least a 50-50 chance the company will be around to honor their warranty if I need them.  

 When I designed the system, I contacted the panel manufacturer (also a Tier 1 company) about drilling holes in the aluminium frame and whether that would affect their warranty.  They responded very quickly and confirmed that provided that the screws, or bolts, which I was proposing to secure the panel to my 'mounting bridges' did not touch, or damage, the under side surface of the white board on which the photo cells are mounted there would not be any problem with them honouring the warranty should a problem be cause by other matters.  Obviously, I have kept that email just in case.

3 hours ago, ThaiFig said:

 Were your tiles new?  Do you know the thickness you used?

The tiles were new when we had the carport constructed in 2018, so 6 years old.  Not sure about thickness.  Sorry but I'm not able to get up there to measure them at the moment.  At a rough guess I would say about 1/4 inch thick.

3 hours ago, Crossy said:

It could have been worse, you could have landed on the car and damaged it as well as the roof!

 

Although that might have reduced the damage to you.

 

@ThaiFig... Sorry I didn't mean to side track your topic with my stupidity.

Looking at the photos taken by my neighbours after the accident, and before the ambulance arrived, I landed just behind the rear of the car.  However, something did hit the car.  I suspect part of the roof tile which shattered the rear n/s window, as seen below.  It cost 5,000 THB to have replaced.  Luckily no damage to the paint work.

32 minutes ago, Crossy said:

@007 RED 

Is the new ventilation hole now fixed?

 

Yes... Local handyman did the repair for a couple of beers.  No way could l do it with a cast on my leg.  Apart from that, my better half has banned me from going up there until l get a walkway put up there.

7 hours ago, SAFETY FIRST said:

Gawd, dead from a leg injury. 🤔

7 hours ago, bkk6060 said:

Sure.  It's called the Femoral artery bleed out in 3 to 5 minutes.

6 hours ago, simon43 said:

Agreed, but if so, why isn't the photo awash with blood?

For your information:

The femur (the large bone in the upper leg (between the pelvis and knee) if fractured (broken) can damage major blood vessels within the upper leg, such as the femoral artery which carried blood from the heart to the lower limb, or the femoral vein which carried blood from the lower limb back towards the heart.

If either of these major blood vessels are damaged, they can bleed profusely inside the upper leg, often with little or no outward signs of blood.  If the bleeding is not controlled very quickly, the amount of blood within the circulatory system rapidly decreases.  This in turn causes the heart to try and pump faster to ensure that there is a sufficient blood supply to the vital organs (brain, liver, kidneys etc).  As more blood is lost, it quickly becomes a ‘vicious circle’, the heart will try to beat faster and faster to compensate for the increasing blood loss.

Unfortunately, the heart can only beat so fast for a relatively short period of time before it goes into cardiac arrest (stops working).  If the bleeding is not controlled, and CPR administered quickly, brain cells will be irreversible damaged, and death will occur.

In the case of a bullet wound (depending upon the size of the bullet), the entry wound is often relatively small, with minimal external bleeding.  The real damage is done when the bullet hits the bone and the bullet and often the bone fragment.  It is these fragments that then damage the major blood vessels (femoral artery and vein) and rapid bleeding then occurs inside the leg and is only noticeable by the rapid swelling of the thigh. 

Regrettably, Thai rescue personnel are, in the main, only trained in very basic first aid procedure (scope and run) and not equipped to undertake advanced life support procedures which would be needed in this case.

Upgrade Update

Up at the crack of dawn yesterday morning to turn off the inverter and the system’s  AC and DC breakers before starting work to connect the two new panels to the existing panels on the carport roof.

I managed to complete the connection and securing the panels onto their mounts before the sun became to strong to continue working on the carport roof.

Back on terra firma, I did a quick check to ensure that the input polarity to the DC breaker was correct before switching everything back on.  Thankfully the needle on the AVO meter swung in the correct direction and showed a reading of 240V (DC), which with the 6 panels, and moderate sunlight, was about what I was expecting.

With fingers crossed, I turned on both of the system breakers and then switched the inverter on.  The inverter went into its start up check sequence and a few moments later the system showed “Normal operation”.  Fortunately no ‘flash bang’ or ‘magic smoke’ thank goodness.

A quick look at meter on the pole outside the house showed that it was merrily spinning backwards at a ‘rapid rate of knots’.  Upon checking the system’s monitoring facility (on my PC), the system showed a marked increase in power produced (e.g. about 40% plus) when compared against the same time the day before.

After a full day of operation the system monitoring facility shows about 45% increase in production, as can be seen from the graphs blow.  Given that there were a few intermittent clouds shading the sun during the day, the increase power production was as I was expecting.

So now having spent an additional 8,000 THB on the 2 extra panel, I hope that they quickly repay my moderate investment.

The only problem that I envisage is that with the added potential production there is a risk that my small scale system may well start pushing the spinning meter into negative territory, so this is something that I will need to monitor in the coming weeks as I certainly don't want the  when the meter reader comes next month.

All good fun.