Solar power, can it be done DIY?

[Crossy]

@SophonFound blanking plates, two sources. Similar prices.

 

https://www.lazada.co.th/products/6-wnj-abb-tz-bp6-i4063253602-s15839843066.html

 

https://shopee.co.th/product/696648702/16254635396?smtt=0.186278822-1663763191.4

 

[Sophon]

On 9/22/2022 at 6:35 AM, Crossy said:

@SophonFound blanking plates, two sources. Similar prices.

 

https://www.lazada.co.th/products/6-wnj-abb-tz-bp6-i4063253602-s15839843066.html

 

https://shopee.co.th/product/696648702/16254635396?smtt=0.186278822-1663763191.4

 

Thanks a lot. What did you use as search terms?

[Crossy]

6 minutes ago, Sophon said:

Thanks a lot. What did you use as search terms?

 

I cheated and got the Thai chap who got me the last ones to search for them

[Sophon]

So a month and a half on, and things are starting to get real.

 

We just picked up 14 of these JinYuan 340W panels from Global:

 

Our local Global here in Lamphun didn't have any in stock, and neither did any other branches here in the North, so Global had to transfer panels from their Buriram branch.

 

Then there is the question about what to do about batteries. You basically have three choices:

• The cheapest option is DIY with cells and BMS bought from China. 
• Buy one of the battery packs assembled by "some guy" here in Thailand. Not much more expensive that doing it yourself, but the option comes with question marks about what quality of cells they are using. They may claim to use new, top quality cells but there is not way to really know. Also, what is the build quality of these battery packs? Finally, most of the packs come with NMC cells, which I personally don't think are very well suited for solar battery storage. Compared to LFP cells, NMC cells have their strong points (high energy density, fast charge/discharge rates neither if which are really needed for solar). But they are not as safe as LFP and have a much shorter life span.
• Buy a factory built battery pack. A good, safe option that more or less guarantee you a quality, well built and nice looking product, but also costs close to twice what it would cost to DIY.

In my opening post I said that I would not be building the battery myself, but after doing the research I have changed my mind. Building your own battery pack really isn't that complicated, and you will know exactly what components goes into the battery.

 

So two weeks ago I ordered 16 pcs. EVE LF280K cells on AliBaba, which will give me a little over 14kWh of storage (10-12 kWh if I leave a 10% bottom and top buffer).

 

The cells were shipped Monday this week, and Friday morning we received a call from Nim See Seng that the cells had arrived in Lamphun, and as we were in the city anyway we picked up the packages at the depot. Just four days for shipping from China, that's pretty rapid.

 

Both the 14 PV panels and the 14kWh of battery storage is a little more than originally planned, but once I start looking at buying something I always end up wanting a little bit extra. When it comes to need vs. want, want often comes out on top (at least for me).

 

Next step is to have the ground mount for the panels built, which will hopefully happen over the next couple of weeks. Similarly to often ending up deciding to upgrade a bit from the original plan when buying stuff, the ground mount will no doubt end up being somewhat overengineered. But better that than have the whole thing fly away during the next thunder storm.

 

.

[Crossy]

Whilst you are waiting for your ground mount to grow I would top-balance your cells.

 

To do this connect them all in parallel, set your bench or other power supply to 3.6V (without the cells connected), connect the power supply to the cells and monitor the current.

DO NOT ADJUST THE POWER SUPPLY!!

Read this ^^^ again!!

Once the current approaches zero (it will take a long, long time, dependent on the current available from your power supply) your cells will be ready to make into your pack.

 

Which BMS are you going to use?

[Sophon]

24 minutes ago, Crossy said:

Whilst you are waiting for your ground mount to grow I would top-balance your cells.

 

To do this connect them all in parallel, set your bench or other power supply to 3.6V (without the cells connected), connect the power supply to the cells and monitor the current.

DO NOT ADJUST THE POWER SUPPLY!!

Read this ^^^ again!!

Once the current approaches zero (it will take a long, long time, dependent on the current available from your power supply) your cells will be ready to make into your pack.

 

Which BMS are you going to use?

Yes, I know about top-balancing the cells, I will start doing that as soon as the adjustable power supply I have ordered arrive.

 

I have bought this BMS:

[BritManToo]

13 hours ago, Sophon said:

Next step is to have the ground mount for the panels built, which will hopefully happen over the next couple of weeks. Similarly to often ending up deciding to upgrade a bit from the original plan when buying stuff, the ground mount will no doubt end up being somewhat overengineered. But better that than have the whole thing fly away during the next thunder storm.

Make it double as a car port/shaded sitting area.

[Sophon]

29 minutes ago, BritManToo said:

Make it double as a car port/shaded sitting area.

It's down in the corner of our land and in the wettest part, the location is not suitable as car port or sitting area.

[Crossy]

22 minutes ago, Sophon said:

It's down in the corner of our land and in the wettest part, the location is not suitable as car port or sitting area.

 

Swimming or mud-bathing then ???? 

[Sophon]

Unfortunately, our project got delayed a couple of months. First it was delayed by unseasonal thunder showers in December, and when that cleared up a village water pipe running along our land right next to the solar panel location broke. For a month and a half no-one could be bothered to fix the pipe resulting in, what at this time of year should be bone dry dirt being absolutely soaked:

This is the trench I had to (have some-one) dig, to gain access to the electrical cable leading to our house.

 

On top of that, one of our dogs got paralyzed by Ehrlichiosis Canis brought on by ticks, and completely lost all control and feeling in his back legs and lower back as well as his bodily functions. So we have had to carry him around and empty his bladder by inserting a catheter every day. We also had to arrange for someone to sit with him, if we had to go somewhere, so all that took up quite a bit of our time. Fortunately, he is now doing better and can walk around on his own, although he is still dragging one of his back legs behind him.

 

Toto during his first acupuncture session:

 

But in the end we managed to have the ground structure for the solar panels build:

 

And the panels mounted:

 

The battery, inverter and other equipment will be mounted in the corner where I will build a small raised semi-enclosed area:

Next step is to put up cementboard for walls on the back and right side to keep the area dry when raining. Front and left will probably just be covered by some kind of tarp to help keeping the area well ventilated and relatively cool.

 

The ground structure is located at the North-Eastern corner of our land close to where the PEA supply lines enter:

 

[Encid]

1 hour ago, Sophon said:

The ground structure is located at the North-Eastern corner of our land close to where the PEA supply lines enter:

That is a nice, neat installation... well done! 

[d4dang]

20 hours ago, Sophon said:

Unfortunately, our project got delayed a couple of months. First it was delayed by unseasonal thunder showers in December, and when that cleared up a village water pipe running along our land right next to the solar panel location broke. For a month and a half no-one could be bothered to fix the pipe resulting in, what at this time of year should be bone dry dirt being absolutely soaked:

This is the trench I had to (have some-one) dig, to gain access to the electrical cable leading to our house.

 

On top of that, one of our dogs got paralyzed by Ehrlichiosis Canis brought on by ticks, and completely lost all control and feeling in his back legs and lower back as well as his bodily functions. So we have had to carry him around and empty his bladder by inserting a catheter every day. We also had to arrange for someone to sit with him, if we had to go somewhere, so all that took up quite a bit of our time. Fortunately, he is now doing better and can walk around on his own, although he is still dragging one of his back legs behind him.

 

Toto during his first acupuncture session:

 

But in the end we managed to have the ground structure for the solar panels build:

 

And the panels mounted:

 

The battery, inverter and other equipment will be mounted in the corner where I will build a small raised semi-enclosed area:

Next step is to put up cementboard for walls on the back and right side to keep the area dry when raining. Front and left will probably just be covered by some kind of tarp to help keeping the area well ventilated and relatively cool.

 

The ground structure is located at the North-Eastern corner of our land close to where the PEA supply lines enter:

 

Hope you dog recovers. My Rottie had ticks near his rectum....he used to spin on his butt to get relief. He was treated for ticks but the vet assistants missed them. Second treatment go rid of them. The vet said he had never seen a case like it

[BritManToo]

1 hour ago, d4dang said:

Hope you dog recovers. My Rottie had ticks near his rectum....he used to spin on his butt to get relief. He was treated for ticks but the vet assistants missed them. Second treatment go rid of them. The vet said he had never seen a case like it

Vet was incompetent,

Ivermectin injections work 100%, but are too cheap (100bht) for most vets to use.

I'd suggest using a different vet, one that puts animal health before profits.

Ivermectin stays in the blood and poisons all insects that suck blood (seen or unseen).

2-3 injections protects the animal from recurrence for up to a year.

 

[d4dang]

1 hour ago, BritManToo said:

Vet was incompetent,

Ivermectin injections work 100%, but are too cheap (100bht) for most vets to use.

I'd suggest using a different vet, one that puts animal health before profits.

Ivermectin stays in the blood and poisons all insects that suck blood (seen or unseen).

2-3 injections protects the animal from recurrence for up to a year.

 

Sadly he was very old and died shortly after the new vet treated him. The old vet apparently did not give him enough Ivermectin. It was 20 years ago. 

[Muhendis]

On 11/13/2022 at 9:45 AM, Sophon said:

It's down in the corner of our land and in the wettest part, the location is not suitable as car port or sitting area.

That's a very sturdy looking fabrication you have there.

Like it.

What number on the Richter scale is it good for?

[Sophon]

1 hour ago, Muhendis said:

That's a very sturdy looking fabrication you have there.

Like it.

What number on the Richter scale is it good for?

Yeah, I tend to overengineer things but it gives me peace of mind. Otherwise I would be worrying every time a strong thunderstorm blew by.

[Sophon]

Equipment is starting to get mounted under the panels, but nothing is wired up yet:

 

With the CU lids on:

 

Next task is to start getting the cables in place, but life is keeping us busy at the moment so progress will be slow over the next few weeks. 

[Sophon]

The C.U.s and inverter are wired up internally, so now I "just" have to connect the peripherals (solar panels, battery, PEA supply and house load). I know the wiring could be neater, but 16 sq.mm seven strand cable is a pain to work with in small spaces:

[Muhendis]

48 minutes ago, Sophon said:

16 sq.mm seven strand cable is a pain to work with in small spaces:

Yeah.

That's why we like to create as much enclosure space as possible.

Getting wires and fingers into a tight space is really quite a needless struggle but what you have achieved looks good and professional.

[Crossy]

Yup ^^^. VSF with its many fine strands is much less of a wrestle, but it really needs ferrules on the ends.

[h90]

On 2/20/2023 at 12:42 PM, BritManToo said:

Vet was incompetent,

Ivermectin injections work 100%, but are too cheap (100bht) for most vets to use.

I'd suggest using a different vet, one that puts animal health before profits.

Ivermectin stays in the blood and poisons all insects that suck blood (seen or unseen).

2-3 injections protects the animal from recurrence for up to a year.

 

Can also buy pill....cost almost nothing....these pills for animals were popular during covid

[Sophon]

So, we got the panels connected on Sunday, which coincidentally was the same day the meter reader came by. Not much production though, since I still hadn't assembled and connected the battery. Got that done on Monday, so now fully up and running.

 

This is from around 11 this morning while charging the EV and producing 3.47 kW:

 

Some friendly advice, don't put your hammer on top of a ladder. I did, and when I accidentally brushed against the ladder, the hammer fell about a meter and hit me dead square center on the top of my head. And not just any normal hammer, no one of these big guys I had been using to hammer in the ground rod:

 

 I had a baseball cap on, which softened the blow slightly, but still not a pleasant experience.

 

Since the system basically started on meter reading day, I expect the next bill to be drastically lower. Hopefully by at least 80%.

[Crossy]

Looking good ???? 

 

Now you know why it's called a "lump hammer"

 

At least it didn't fall on anything important ???? 

[Sophon]

So, Sunday morning I read the meter exactly one week after the official meter reader person came by. For that week we had used 21-22 kWh from PEA, while our consumption for the previous month without solar (and the first month with our new EV) was 450 kWh. 450 kWh for the month comes out to about 100-110 kWh per week, so the 21-22 kWh equates to savings of about 80%.

 

I'm pretty happy with that, especially considering that:

We only turned on the solar panels on the afternoon of the day the meter was read,

The battery was not connected until the afternoon of the day after the meter date,

The BMS is still trying to calibrate to the battery, initially it was showing battery at 25%, when it was really 90% full. To teach the BMS when the battery is full/empty, I intentionally let the battery run way down by dumping the energy into the EV. So we ended up using PEA more than necessary because of the empty battery. 

[Danderman123]

I live in a North facing condo, so have very límited opportunities for solar.

 

I plan to install about 600 watts of panels to feed into a grid tie inverter. Another 200 or 300 watts to Charge up a small battery bank that will power an emergency puré sine wave Inverter.

 

These panels will only receive full Sun a few months of the year.

[Sophon]

Another week has passed, this time with the system fully operational for the whole time, so time for another trip to the PEA meter. Over the last week we have imported 5.5 kWh, so down 95% compared to what we used per week in the month before our solar system was installed.

 

The weather has been sunny lately with very few clouds, but we live in the North so there has also been a thick haze due to the pollution. So good, but by no means perfect conditions for solar production.

[Sophon]

Today was the first day for PEA to read our meter since our system went online.

 

Last months bill:

 

This months bill:

 

So import from PEA down 93% since last month.

 

Even better, of the 33 units we imported, 21-22 was in the first week where the system was not fully operational for the first two days (no battery). Meaning that import was only down 80% the first week.

Then the following two weeks, where i was still learning when and how much I can charge the EV and still have enough in the house battery, we imported 5-6 units per week. So import down 95% for those two weeks.

For the last nine days we have imported exactly zero from PEA.

 

And that is while our area has been (and still is) blanketed by smog limiting the production of the PV panels. For the last three weeks the most I have seen is around 2.7 kW, which is 56% of the panels rated capacity. In the first week, when the haze was not quite as bad but still not good, we produced 3.5 - 3.8 kW at midday.

 

So far very happy with the results given that the initial goal was to save at least 80% and avoid the fairly frequent power outages.

[Sophon]

Interesting development.

 

A couple of weeks ago, the power in our house suddenly went out around 10 in the morning. The solar equipment is in the corner of our land, so when I went to investigate it probably took me a couple of minutes to get down there. As I was about 10 meters away I heard a pop from the inverter, and smoke started pouring out of the vent opening. Sure enough, the inverter was fried and refused to turn on again. I took the cover of the inverter off to see if a jingjok had gotten itself fried, but nothing was immediately obvious and I didn't want to mess around in there and accidentally touch a capacitor.

 

As it turned out, it wasn't only the inverter that was fried:

I have a DIN rail power meter with over- and under voltage protection on the incoming line from PEA so I can monitor my usage. That power meter refused to stay on and kept restarting.

The surge arrestors on my solar panels are blown (or at least I assume they are, they look like this):

 

As you can see, the surge arrestors on the incoming PEA supply looks OK.

The BMS for my battery works, but is acting strange. The Bluetooth keeps turning off on it's own, and some of the functionality doesn't seem to work. When I turn off charging/discharging in the app nothing happens.

 

So I ordered a new inverter, and this time went for a larger 8.2kW model even though the old 5.5kW was big enough for our needs, hoping the components would be a little sturdier in a larger model. It also gives me flexibility to add more PV panels in the future, should I so wish.

 

Of course, while waiting for the new inverter to be delivered we have had to rely on power from PEA, so imagine my surprise when the bill was delivered this morning and it showed a usage of zero kWh. As it turns out the PEA meter is also blown, even though there is nothing visibly wrong with it. As a test I turned off my battery and started charging my EV with PEA power (supplemented by a little solar, it's mostly overcast this morning), and the disc in the PEA meter is frozen in place. Even when charging both the EV and the house battery with PEA power, nothing moves in the meter.

 

A quick visit to the PEA meters of our two closest PEA up-stream neighbors show one meter spinning and one frozen in place. I don't (yet) know for sure if that neighbor meter should be spinning, but one would imagine that there would at least be a fridge running or something on stand-by in the house. SWMBO saw the neighbor collect his bill this morning, and he spent a long time examining the bill seemingly confused by something. So maybe he was surprised by the bill amount, which would be approximately half of normal if his meter is also broken. We will talk to him later, when he comes back.

 

There was no lightning at the time, so I don't know what kind of event could knock out a PEA meter (possibly multiple meters), an hybrid off-grid solar inverter, a power meter with over voltage protection on the incoming supply and mess with the electronics in my BMS. Nothing in our house was effected. I have a hard time seeing how a fault originating in my off-grid hybrid inverter could knock out our PEA meter, so I am leaning towards the most likely reason being some kind of voltage/power spike event coming from PEA.

 

So now I have a moral dilemma. If the cause of my blown equipment came from PEA, then they kind of owe me a new inverter. We all know that the PEA is not going to compensate me for equipment in an unofficial solar installation, so should I compensate myself on their behalf by not reporting the defective meter and let them find out on their own? As they know we have solar (the panels are five meters from the PEA meter and in plain sight), it might take a while for them to connect the dots. That is, unless our PEA meter isn't the only one that broke.

As we are almost completely self-sufficient when it comes the electricity because of our solar installation, the savings won't be all that significant. The only reason we used the PEA in the last month was because our inverter burned out and we had to wait for a new one. 

 

So, what say ye? What kind of event do you think happened to cause this kind of damage, and would you report the broken meter to PEA or wait for them to find out on their own?

[Muhendis]

Do you have surge arrestors on you incomer from PEA?

If you do. 

Are they located immediately after the incoming power breaker/isolator?

[JBChiangRai]

On 8/1/2022 at 4:35 PM, Tubulat said:

To give you a hint, with that consumption per month I would think twice before making a big investment.

Yes I have solar cells including batteries and meets my needs for 95%, my month average was about 2500 thb.

It is working now for about 15 months.

But I've got problems with one of the 2 inverters I use and in this country, they like to sell to you but if you have problems, they can't help you.

It's a lot of investment and, I think about 350-400 thousand bath did it cost me, (12 solar cell panels aver. 500W, 2 inverters, and 2 lithium battery packs, each 260Ah) so when everything is correct working it will takes 12.5 years before you even broke.

Anyway, that's my experience.

Oh, yes I forgot to mention, I did everything by myself.

I don't see a data cable between your inverters, required to make them synchronise.

 

Also, is the cable run from each inverter to battery, the same length and size?