Skip to content
View in the app

A better way to browse. Learn more.

Thailand News and Discussion Forum | ASEANNOW

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

I would like to see the effect of sun in south on panels with different inclanations in Hua

Featured Replies

Is there a table for this or can anybody help me?

I have 8 panels on 2 places towards south and they give very different current, about 20% difference.

I don't know the inclanation of them, will check today.

Either the differnce in inclanation gives the difference or a problem have ocurred

PVwatts is a pretty good resource.

 

https://pvwatts.nrel.gov/

 

Any potential shading from trees, house etc?

Are you actually maxing out your inverter so it can't make use of all the power you are generating?

Are your batteries full (and you're not exporting)? Try turning on some load (kettle, microwave etc etc.)

 

If you are getting roughly the same amount of energy (Watt Hours) in a day from each array I wouldn't be overly worried. 

 

EDIT Right now two of our inverters (#2 & #3) are throttled right back, batteries are full and minimal house load (no exporting).

 

image.png.509acca5d0219af7c7534048dbac5d17.png

"I don't want to know why you can't. I want to know how you can!"

  • Author
5 minutes ago, Crossy said:

PVwatts is a pretty good resource.

 

https://pvwatts.nrel.gov/

 

Any potential shading from trees, house etc?

Are you actually maxing out your inverter so it can't make use of all the power you are generating?

 

If you are getting roughly the same amount of energy (Watt Hours) in a day from each array I wouldn't be overly worried. 

Thanks for the link, I hope I will understand!

Nothing shading!

1 group on roof of carport (slave inverter), 1 group on house roof (Master inverter). Inverters connected in parallell to get 64 A load on each phase

Both absolute south orientation

I never heard of maxing out inverter (Sofar HYD20KTL-3PH), is it possible and how to do? Info in manual?

I don't know how to see the dayly effect on Solarman Business. Is it possible to see on each connection?

On Slave I have PV1: Carport 8 panels in serie, PV2: east 7 panels in serie

On Master I have PV1: Roof house south 8 panels in serie, PV2: west 7 panels in serie

 

From your other thread I gather you have:-

  • 30 x panels of about 530W each
  • 2 x 20kW 3-phase inverters
  • 35kWh of storage

I admit to being intrigued as to why you have 40kW of inverter with only 16kW of panels. Future expansion maybe?

 

Anyway, with so few panels you are nowhere near maxing out your inverters and so limiting the available power. In fact you could even be under-paneled for the MPPTs to make it into their ideal working zone.

 

What is the state of charge of your batteries? If there's nowhere for the energy to go it won't get made.

 

"I don't want to know why you can't. I want to know how you can!"

  • Author
32 minutes ago, Crossy said:

From your other thread I gather you have:-

  • 30 x panels of about 530W each
  • 2 x 20kW 3-phase inverters
  • 35kWh of storage

I admit to being intrigued as to why you have 40kW of inverter with only 16kW of panels. Future expansion maybe?

 

Anyway, with so few panels you are nowhere near maxing out your inverters and so limiting the available power. In fact you could even be under-paneled for the MPPTs to make it into their ideal working zone.

 

What is the state of charge of your batteries? If there's nowhere for the energy to go it won't get made.

 

The reason for 2 inverters is the electric car ;-). The big charger is for 32A in 1 phase and that is maximum for the inverter. And as we have a 3 phase house there are many things on every phase

Expansion of panels? the problem are the batteries 35 kW, too little and they are expensive and the say I can add more because the problem to align them to the old. After 6 months I was successfull to add 4 to the 10 I had. So that is the reason why I try connect to PEA, sell power and buy power when batteries are low.

"If there's nowhere for the energy to go it won't get made." Please explain

  • Author
2 hours ago, Crossy said:

PVwatts is a pretty good resource.

 

https://pvwatts.nrel.gov/

 

Any potential shading from trees, house etc?

Are you actually maxing out your inverter so it can't make use of all the power you are generating?

Are your batteries full (and you're not exporting)? Try turning on some load (kettle, microwave etc etc.)

 

If you are getting roughly the same amount of energy (Watt Hours) in a day from each array I wouldn't be overly worried. 

 

EDIT Right now two of our inverters (#2 & #3) are " batteries are full and minimal house load (no exporting).

 

image.png.509acca5d0219af7c7534048dbac5d17.png

Interesting! So this is 4 inverters. And this information you can see in picture in your program?

I wounder if I can see that too in my Solarman business? I think I will see if I can find a manual

"throttled right back," Which means?

Attach a picture of my electric central. Made by a former colleague of me that let build this house. Little unusual in Thailand I think

elabb.JPG

47 minutes ago, Anders Eriksson said:

"If there's nowhere for the energy to go it won't get made." Please explain

 

 

If you are using less than the panels could potentially supply and your batteries are full you are effectively "wasting" energy, this could of course be mitigated by exporting to PEA as you would like to do.

 

24 minutes ago, Anders Eriksson said:

"throttled right back," Which means?

 

We do not export, I gave up trying to get approval for our DIY system so the grid really only gets used to top up the batteries if we've had a run of dull days. Once the packs are full the inverters cut production to match what we are using in the house. This is a good time for Madam to run the dryer or to plug in the car which we don't yet have. 🙂 

 

Batteries are getting cheaper very quickly (we have 90kWh) it may prove more cost effective to add storage rather than use PEA as your "battery" particularly with the significant difference between their "buy" and "sell" rates.

 

My numbers come from Solar Assistant, sadly, it doesn't currently work with Sofar inverters, you should be able to find similar data in the Solarman app.

  

 

"I don't want to know why you can't. I want to know how you can!"

Some graphs for today.

 

You can clealy see the solar production drop off after mid-day as the batteries approach full charge.

 

image.png.9fea14399a44c7b4694a49df5d5885b3.png

"I don't want to know why you can't. I want to know how you can!"

On 6/23/2025 at 2:24 PM, Crossy said:

From your other thread I gather you have:-

  • 30 x panels of about 530W each
  • 2 x 20kW 3-phase inverters
  • 35kWh of storage

I admit to being intrigued as to why you have 40kW of inverter with only 16kW of panels. Future expansion maybe?

 

Anyway, with so few panels you are nowhere near maxing out your inverters and so limiting the available power. In fact you could even be under-paneled for the MPPTs to make it into their ideal working zone.

 

What is the state of charge of your batteries? If there's nowhere for the energy to go it won't get made.

 

And using inverters well under their rated power means much lower efficiency, wasted panel power in conversion.

Hello Anders, l believe we are both  located in Hua Hin and like Crossey l have also installed a DIY Solar installation 2.9Kw (Deye Grid Tied Micro Inverter) at the moment but plan to expand to about 5Kw, l could put 20 panels on my south facing roof but l don't want to break my neck climbing at 65yrs old or pay someone 250,000Baht for the privilege and my free Battery Storage is called the PEA.

 

So, l have installed all the panels myself on a lower more accessible 25 degree roof sloping North and East/West and like Anders l have been scratching my head and doing my sums to workout the best inclination angles and now decided to remove and adjust the fixing brackets of every panel adjusting the slope inclination to 15 degrees or more increasing the output of each panel by about 12%.

 

Also Anders at this time of year just to remind you the Asimov and Altitude of the Sun is towards the North 78 degrees but gradually it will travel towards the South for the rest of the year.

 

Its been an interesting little project, my East and West Panels now share the same individual MPPT input saving the expense of buying an additional invertors and generating from dawn till dusk.

 

There is a free PV Calculator in the Google App Store, also Angle Inclination Apps and Sun Locator, 

 

The App is called                PV Calculator by susenergy

 

 

The basic rule for best year round performance is panels facing due south (in northern hemisphere) at an angle of the latitude of where panels are being installed. For example Chiang Mai is 18.8 N so inclination should be 18.8 degrees in Chiang Mai.

Create an account or sign in to comment

Recently Browsing 0

  • No registered users viewing this page.

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.