Solar power, can it be done DIY?

[BritManToo]

7 minutes ago, Sophon said:

I realize that this may work differently between different models, but can the "inverter" be set up so that it only charges from the mains if the battery falls below a certain level of charge?

 

With regards to the essential load, can I connect the whole house to both the normal load port and to the essential load port. I assume (I know, dangerous) that the essential port is  limited to the maximum power of the inverter, so I won't be able to just connect the whole house to the essential port?

I don't want to split my circuits into two groups.

 

Thank you for your explanation.

Why would you want to charge the battery from the mains?

Inverter switches to mains when there's no battery or PV.

 

Why wouldn't you want to split the circuits?

I have most of my house wired through the inverter.

But my air-con, showers and a kitchen double socket wired to the mains.

[Crossy]

1 minute ago, BritManToo said:

Why would you want to charge the battery from the mains?

 

To keep a minimum charge level for your essentials, possibly to charge at night on cheap ToU energy to use during the day and supplement your solar. Most of us don't, but it's there as part of the inverter anyway.

[BritManToo]

4 minutes ago, Crossy said:

To keep a minimum charge level for your essentials, possibly to charge at night on cheap ToU energy to use during the day and supplement your solar. Most of us don't, but it's there as part of the inverter anyway.

More like the OP has a basic lack of understanding, lots of woolly thinking displayed on this thread. Installing a solar system isn't for everyone, and in some cases could be extremely dangerous.

[lom]

12 minutes ago, Crossy said:

Note:- There are off-grid hybrids that can export, but they do seem to be generally weak in this area.

 

To where do they export if the are off-grid?

[Crossy]

4 minutes ago, lom said:

To where do they export if the are off-grid?

 

It's a hybrid, so it has a grid connection, you need to read the pinned thread on inverter types ???? 

 

Calling it an "off-grid hybrid" is counter intuitive I know, it's really an off-grid with a battery charger (most are a little smarter than that but generally).

[lom]

29 minutes ago, Crossy said:

 

It's a hybrid, so it has a grid connection, you need to read the pinned thread on inverter types ???? 

 

Calling it an "off-grid hybrid" is counter intuitive I know, it's really an off-grid with a battery charger (most are a little smarter than that but generally).

I have read the pinned thread by you and as far as I can see by your definition it is only the on-grid inverter and the on-grid hybrid inverter that are able to export to the grid ????

[Crossy]

6 minutes ago, lom said:

I have read the pinned thread by you and as far as I can see by your definition it is only the on-grid inverter and the on-grid hybrid inverter that are able to export to the grid ????

 

Yeah, just to confuse there are off-grid hybrids (with separate mains in and out connections) which can actually export via the mains in connection. They are sometimes referred to as on/off-grid hybrids, but that term is also used for what are really plain off-grid hybrids. It's a nightmare of terms and marketing I'm afraid. You have to read the specs very carefully to see what you are really buying.

 

 

[KhunLA]

3 hours ago, KhunLA said:

On that, the solar guys arrived and being installed as I type. 

Installed in less than 4 hrs ... 18 panels ... ????

[MJCM]

8 minutes ago, KhunLA said:

Installed in less than 4 hrs ... 18 panels ... ????

WOW!!!

 

????

[Sophon]

1 hour ago, Crossy said:

 

Yes.

 

Yes, but it does depend upon your inverter.

 

If you don't want to split your circuits you can either, not bother using the essential output (and have the lights out when the mains is off) or get an off-grid hybrid with sufficient oomph to supply your whole house and forgo exporting.

 

Note:- There are off-grid hybrids that can export, but they do seem to be generally weak in this area.

 

I obviously don't want to have the power go out, an important part of the project is to avoid that.

 

A 5 kW inverter would easily supply my whole house, the only thing I would have to avoid is charging the EV, especially if I in the future install a 7 kW home wall box..

 

What I would like to achieve is:

• When PEA power is on, I want to supply the whole house and also have the ability to go above the 5 kW inverter limit (when charging the EV).
• When PEA power is off, I still want to supply the whole house, but will manually take care not to use the most power hungry utilities (i.e. EV charging) to avoid exceeding the inverter limit.

But how would I connect the house load to the inverter. I assume that there must always be power going to the essential output port, but that it is limited to 5 kW. The non essential output port can go above the inverter limit, but will have no power when the grid is out, is that correct?

 

So would I need to connect both ports to a changeover switch like this one (and would that work)?:

 

default would be keeping the switch to take input from the essential load port limiting me to 5 kW power, and switching it over to take input from the general power load port when I need more than 5 kW and know that the grid is active.

 

Would that work, and is there a more elegant solution?

 

What would happen if both output ports were connected to the house load at the same time, without a changeover switch, would something go poof?

[Sophon]

1 hour ago, BritManToo said:

Why would you want to charge the battery from the mains?

Inverter switches to mains when there's no battery or PV.

 

Why wouldn't you want to split the circuits?

I have most of my house wired through the inverter.

But my air-con, showers and a kitchen double socket wired to the mains.

Because the inverter will be located 50 m from the house, so it would require a second buried cable as well as a major rewiring of the house.

 

As I mentioned before, I wouldn't generally charge from the mains as that would be counterproductive, but maintaining a small charge to give UPS functionality could possibly be helpful.

 

I am just in information gathering mode at the moment, trying to ascertain what is possible and what is not. Then a few months down the line when i am ready to go, I will be better equipped to decide how to design the system.

[KhunLA]

Components of:

DEYE SUN-8K-SG01LP1-EU 8kw Single Phase Hybrid Solar inverter

Priced (big range): Alibaba ฿55k (non manufacturer), not inc. shipping/duty

฿100k+ on AliExpress (not inc shipping/duty)

฿77k on LAZ, though photo close but not same

No buyers

 

SunTech Solar Panels:  18 @ 540w

Price ?  ... seen for ฿6500, installer charged ฿15k (฿7500 ea. 2X installed) over original contract, from 16 panels to 18 panels.

 

10kWh ESS / Battery back up, asked how much for a 2nd, if wanting to parallel in.

Quoted: ฿95k

 

DIY:

Inverter: ฿77 +/+ ?

Panels: 18 @ ฿6500 = ฿117k

ESS: ฿95k

TTL: ฿289k +/- for components

 

Installed price: ฿345k - 4 man crew + mounts, tracks, cables, tools, knowledge

AND ... warranty w/installer having 20 yrs installation experience (per website)

 

 

 

[007 RED]

Hi @Sophon, me again.

 

I see from your original, and a subsequent, post that you mention that you are thinking that 10 or 12 x 330W solar panels will be sufficient for your needs.   Are you sure?

 

Potentially 12 x 330W panels should in theory give you almost 4,000W (4kW) output.  Assuming 6 hours of good strong sunlight per day.   The key word in this statement is theory.

 

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 70⁰C or 80⁰C.   Unfortunately, the hotter the panels become the greater the loss of the panel’s potential efficiency.  Below is a reading which I took with a basic handheld electronic thermometer of my panels at mid-day on a good sunny day.  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.

 

Also when calculating how many units (kWh) the system will produce a day, it is advisable to work on 6 hours of good strong sunlight a day as the panels are only likely to produce minimal output between sun rise and mid-morning, and between mid-afternoon and sun set, as will be seen from the graph below taken from my small scale system in February this year.

 

I appreciate that you may well be aware of the points I've made above and taken them into account in your calculations.  In which case I apologise for pointing out something that you were aware of.

 

Again, good luck with your proposed project.

[MJCM]

32 minutes ago, KhunLA said:

Components of:

DEYE SUN-8K-SG01LP1-EU 8kw Single Phase Hybrid Solar inverter

Priced (big range): Alibaba ฿55k (non manufacturer), not inc. shipping/duty

฿100k+ on AliExpress (not inc shipping/duty)

฿77k on LAZ, though photo close but not same

No buyers

 

SunTech Solar Panels:  18 @ 540w

Price ?  ... seen for ฿6500, installer charged ฿15k (฿7500 ea. 2X installed) over original contract, from 16 panels to 18 panels.

 

10kWh ESS / Battery back up, asked how much for a 2nd, if wanting to parallel in.

Quoted: ฿95k

 

DIY:

Inverter: ฿77 +/+ ?

Panels: 18 @ ฿6500 = ฿117k

ESS: ฿95k

TTL: ฿289k +/- for components

 

Installed price: ฿345k - 4 man crew + mounts, tracks, cables, tools, knowledge

AND ... warranty w/installer having 20 yrs installation experience (per website)

 

 

 

Wow.

 

Who was your installer?

[Sophon]

26 minutes ago, 007 RED said:

Hi @Sophon, me again.

 

I see from your original, and a subsequent, post that you mention that you are thinking that 10 or 12 x 330W solar panels will be sufficient for your needs.   Are you sure?

 

Potentially 12 x 330W panels should in theory give you almost 4,000W (4kW) output.  Assuming 6 hours of good strong sunlight per day.   The key word in this statement is theory.

 

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 70⁰C or 80⁰C.   Unfortunately, the hotter the panels become the greater the loss of the panel’s potential efficiency.  Below is a reading which I took with a basic handheld electronic thermometer of my panels at mid-day on a good sunny day.  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.

 

Also when calculating how many units (kWh) the system will produce a day, it is advisable to work on 6 hours of good strong sunlight a day as the panels are only likely to produce minimal output between sun rise and mid-morning, and between mid-afternoon and sun set, as will be seen from the graph below taken from my small scale system in February this year.

 

I appreciate that you may well be aware of the points I've made above and taken them into account in your calculations.  In which case I apologise for pointing out something that you were aware of.

 

Again, good luck with your proposed project.

No, I am not sure that 12 panels is enough but I believe they probably will be. If it turns out it's not enough I can always add more later.

 

With your own estimates of 75% efficiency and 6 hours of sunlight per day and 12 pcs 340 W panels, I make it a production of 340*12*.75*6 = 18 kWh on an average day. Our consumption over the last several years have been between 11-12 kWh per day, so well below the average expected 18 kWh output from the panels. When we get our new EV, our consumption will probably increase by about 3 kWh per day, so still below the 18 kWh/day.

 

I appreciate that averages are just that - averages. There will be days when we use more than our normal 11-12 kWh, and there will be days when the panels produce less than the average 18 kWh. Most days the panels should be able to cover our consumption, and on days where they are not, well that's what PEA is there for.

 

Please don't apologize for giving information I may already be aware of. As I am a new to this there is a good chance the information you give is something I don't already know. And even if I did know something already, it's always good to have information reinforced and it could also be of benefit to other people.

[007 RED]

Hi @Sophon, again

 

FYI…. At present the price of solar panels is quite high compared to this time last year.  This has been in no small part due to the worldwide shortage of silicon chips which may have something to do with various sanctions being placed on China who are the biggest manufacture of chips and in our case solar panels.

 

Last year when I purchased my 415W, monocrystalline half cut panels they were approximately 3,800 THB each at a discount price including delivery.  Today they appear on the web to be around 5,200 THB each (delivery fee not known).

 

I see from your initial, and a subsequent post, that you are considering 330W solar panels, and I note that you once asked for a clarification between the different types of solar panels.  So here's some basic information for you.

 

The most common types of solar panels used for both home and commercial installations are monocrystalline and polycrystalline panels, often referred to as mono and poly panels respectively.

 

FYI…. There are other types of panels, for example; Passive Emitter and Rear Cell (PERC) panels and Thin-Film panels, but these are very expensive and tend to be used in specialist applications.

 

All solar panels have the same purpose namely, to convert sunlight into electricity. However, the crystalline structure of the individual cells, which make up the solar panel, determines the overall performance of the panel.

 

Monocrystalline panel cells are produced from a single silicon crystal, whereas polycrystalline panel cells are manufactured from multiple silicon fragments which have been fused together.

 

By virtue of their manufacturing process, monocrystalline solar panels have a higher conversion efficiency than their polycrystalline counterparts, which means that they (mono panels) can potentially produce more kilowatt-hours of electricity for a given area of panel than their poly counterparts.  However, because monocrystalline panels more complex to produce they are more expensive.

 

FYI….  Monocrystalline panels are black in colour, whereas polycrystalline panels are blue.  A very important factor if you are colour conscious about your installation.

 

Although the physical size (height/width/thickness) are fundamentally the same, panels can be described as being full or half-cut.  This describes the configuration of the individual cells which make up the panel.  Half-cut panels are less prone to efficiency loss due to shading, dirt, miss match of cell etc than their poly counterparts.

 

Looking at the Globalhouse website for example, you will see they have various solar panels advertised. 

https://www.globalhouse.co.th/catalog/catagory/125/1

 

So based on your desired panel output of approximately 18kWh, you could be looking at:

 

12 x 330W poly panels @ 4,000THB each = 48,000THB, or

 

10 x 410W mono half-cut panels @ 5,190 each = 51,900THB, or

 

9 x 450W mono half-cut panels @ 5,600 each = 50,400THB.

 

Given that mono half cut panels are more efficient, you may wish to consider them and going for the higher W as there is only a couple of thousand THB in it and it will mean you need less mountings and cable etc

[Sophon]

1 hour ago, 007 RED said:

Hi @Sophon, again

 

FYI…. At present the price of solar panels is quite high compared to this time last year.  This has been in no small part due to the worldwide shortage of silicon chips which may have something to do with various sanctions being placed on China who are the biggest manufacture of chips and in our case solar panels.

 

Last year when I purchased my 415W, monocrystalline half cut panels they were approximately 3,800 THB each at a discount price including delivery.  Today they appear on the web to be around 5,200 THB each (delivery fee not known).

 

I see from your initial, and a subsequent post, that you are considering 330W solar panels, and I note that you once asked for a clarification between the different types of solar panels.  So here's some basic information for you.

 

The most common types of solar panels used for both home and commercial installations are monocrystalline and polycrystalline panels, often referred to as mono and poly panels respectively.

 

FYI…. There are other types of panels, for example; Passive Emitter and Rear Cell (PERC) panels and Thin-Film panels, but these are very expensive and tend to be used in specialist applications.

 

All solar panels have the same purpose namely, to convert sunlight into electricity. However, the crystalline structure of the individual cells, which make up the solar panel, determines the overall performance of the panel.

 

Monocrystalline panel cells are produced from a single silicon crystal, whereas polycrystalline panel cells are manufactured from multiple silicon fragments which have been fused together.

 

By virtue of their manufacturing process, monocrystalline solar panels have a higher conversion efficiency than their polycrystalline counterparts, which means that they (mono panels) can potentially produce more kilowatt-hours of electricity for a given area of panel than their poly counterparts.  However, because monocrystalline panels more complex to produce they are more expensive.

 

FYI….  Monocrystalline panels are black in colour, whereas polycrystalline panels are blue.  A very important factor if you are colour conscious about your installation.

 

Although the physical size (height/width/thickness) are fundamentally the same, panels can be described as being full or half-cut.  This describes the configuration of the individual cells which make up the panel.  Half-cut panels are less prone to efficiency loss due to shading, dirt, miss match of cell etc than their poly counterparts.

 

Looking at the Globalhouse website for example, you will see they have various solar panels advertised. 

https://www.globalhouse.co.th/catalog/catagory/125/1

 

So based on your desired panel output of approximately 18kWh, you could be looking at:

 

12 x 330W poly panels @ 4,000THB each = 48,000THB, or

 

10 x 410W mono half-cut panels @ 5,190 each = 51,900THB, or

 

9 x 450W mono half-cut panels @ 5,600 each = 50,400THB.

 

Given that mono half cut panels are more efficient, you may wish to consider them and going for the higher W as there is only a couple of thousand THB in it and it will mean you need less mountings and cable etc

I don't really care whether  the panels are blue or black, to be honest the lack of symmetry if having 9 panels mounted in two rows would bother me more.

 

Following your link, I can not find all your panels at your quoted prices. However, I did find this additional 340 w panel on sale:

 

link.

 

I think Crossy have previously bought that panel.

 

I assume your 410 w panel is this one.

 

link

 

The only 450 w panel I could find is this one, but the price is lower than you quoted

 

link

 

The slight problem with the higher rated panels is, that they are slightly bigger and heavier. The metal for my structure comes in lengths of 6 m, so with the 340 w panels being 99 cm x 196 cm they fit neatly with two rows of 6 panels. The 450 w panels are 104 cm x 210 cm, so would not fit as neatly. But that's just a slight niggle, it will not be the deciding factor.

 

I have seen Crossy say several times that if there is no limitations on mounting space, he would go for the most watt per Baht. With the 340 w JinYuan panels on sale, that would at this time make them the best value for money at THB 41,880 for 12.

 

I really appreciate you taking the time to dig up and post information for me.

[patman30]

On 8/3/2022 at 5:23 PM, MJCM said:

May I ask some questions?

 

1- what was the import duty on these?

2- How long it take from ordering till delivery?

3- And which Battery? Link?

 

1. Apperently none (LOL was my response too, but will see, shipping agent said included in the $300 shipping)

2. dont expect it to be quick, you are realisticly looking at upto 3 months atm, will update when they arrive

3. i purchased Felicity. i seen the older model on lazada from 2 sellers, only 1 seller had stock but was expensive at 100k each

Felicity sell everything, so you could get inverters etc from them too
https://www.felicitysolar.com/lithium-battery-system_c1

[BritManToo]

31 minutes ago, patman30 said:

2. dont expect it to be quick, you are realisticly looking at upto 3 months atm, will update when they arrive

My inverter from China arrived in less than 3 weeks. 

[KhunLA]

Those considering solar, you really need to install it.  Even on a really bad day it's still produces enough electric to run the house. 

 

Here's a video of now, as this week's been terrible and following week is going to be terrible, overcast and rain and it's still producing enough electric.

 

 

[patman30]

1 hour ago, BritManToo said:

My inverter from China arrived in less than 3 weeks. 

Lucky you, was that very recently?

take note of the word "upto"

from initial order to delivery, i will quote total time when they arrive
for the 3 batts
it was nearly 3 weeks after i paid deposit, i paid remaining balance
then a week delay, so 1 month already before they were even shipped

single inverter may be ready in stock to ship.
it can also be sent by AIR or SAL

these batts are 159KG EACH
lots of delays on sea freight atm
some will get lucky, others wont

my reply was not an optimistic one but a realistic timeframe a buyer should expect due to current conditions
i did not state it would take at least 3 months
but upto 3 months is possible at present
 

[patman30]

1 hour ago, KhunLA said:

Those considering solar, you really need to install it.  Even on a really bad day it's still produces enough electric to run the house. 

i have seen a lot of people recently installing small on grid systems without power storage/battery
(huawei pushing a lot of these inverters/systems atm)
just to cover running aircons etc in daytime
the savings are likely more substantial this way when not looking to fully replace grid power
especially if you use the most power during sunlight hours

[Crossy]

1 hour ago, patman30 said:

i have seen a lot of people recently installing small on grid systems without power storage/battery
(huawei pushing a lot of these inverters/systems atm)
just to cover running aircons etc in daytime
the savings are likely more substantial this way when not looking to fully replace grid power
especially if you use the most power during sunlight hours

 

Yeah, I've got a couple of mates looking at doing just this coz they're at home during the heat of the day.

 

[KhunLA]

2 hours ago, patman30 said:

i have seen a lot of people recently installing small on grid systems without power storage/battery
(huawei pushing a lot of these inverters/systems atm)
just to cover running aircons etc in daytime
the savings are likely more substantial this way when not looking to fully replace grid power
especially if you use the most power during sunlight hours

Yes, and the cost of 5kW system w/no ESS is simply too inexpensive not to do.   When first shopping, over a year ago, our installer was doing them for 135k.  

 

Having now, that would more than suffice our needs, and feed back to the meter to make up for what's used over night.

 

We used about 4.3kW last night, w/AC running + 2 frigs (12 hrs), laptop & 65" TV (6 hrs).

 

Shortly after I posted the vid, the sun popped through, still not good angle on S panels, and the battery topped up in couple hrs.

 

Having solar now, really does expose the farce of MMGW, and how easy, if believing, it would be to solve.  At one point, the panels were generated 5.67kW, and we were using 0.4kW, meaning at the moment, we were generating enough for 10 houses, all things being equal.

 

But PEA won't buy the excess.  Do the math, times the house that can generate, more than needed, to share to the grid, for those, complexes that don't have the m² to generate enough.

 

There is no reason why all residential energy isn't from solar.  We all know, or should know why it's not.  And we only have an 8kW system, with 2X more roof available if wanting to utilize.  Didn't use 'E' veranda roof (pee'd about that), didn't use storage room roof, or the huge carport.

[KhunLA]

Two 9 panel strings, though actually wanted three 6 panel strings, using E veranda roof, but builder F'd me.  Installer didn't think it would support the extra weight properly ... ????

 

 

 

[Crossy]

That 3rd picture is either a huge panel or a little guy ???? 

[MJCM]

^ 55555555555555

 

Nice Pics! @KhunLA

 

 

[MJCM]

We have approx the same roof structure (except it's ONE long Roof and approx 14 meters width) but my wife is totally afraid that after the installers leave the roof leaks.

So she is totally against (from the beginning) to have the panels sit on our roof.

 

I can show you pictures, but need to borrow your drone 55555555555555

 

Ps: Will try throwing my camera up in the air hope it has the same result

[MJCM]

24 minutes ago, Crossy said:

That 3rd picture is either a huge panel or a little guy ???? 

Dimensions (for the Panel not of the little guy ???? )
2279 × 1134 × 35 mm
(89.7 × 44.6 × 1.4 inches)

[Crossy]

2 minutes ago, MJCM said:

Dimensions (for the Panel not of the little guy ???? )
2279 × 1134 × 35 mm
(89.7 × 44.6 × 1.4 inches)

 

I know not these "inches" of which you speak!