[vj_v3]

Originally Posted by DIY410

Yes.

But one thing that makes On grid/grid tie solar less attractive in bescom is, you can only export the sanctioned load.

BESCOM seems pretty aggressive for a govt owned company with all these charges etc. Eventually all state owned companies will start doing the same i guess. As of now TS discom seems pretty liberal and reasonably priced compared to some other states. I get frustrated paying 260 Rs min charges for my 3 phase connection, was Rs. 180 few months ago before the price hike.

Hope, used EV LFP batteries start making it into the open market in a couple of years. With some diy battery packs, these will be ideal to cycle everyday for solar applications.

[GKR9900]

In Kerala, KSEB seems to be gearing up to change into gross metering for on grid systems. If so, this beats any savings that we can hope for using a solar at home right? KSEB is appealing for the second time in the last year for this proposal. Is going off grid the only solution to this?
https://www.onmanorama.com/news/kera...wer-units.html

[di1in]

Originally Posted by GKR9900

In Kerala, KSEB seems to be gearing up to change into gross metering for on grid systems. If so, this beats any savings that we can hope for using a solar at home right? KSEB is appealing for the second time in the last year for this proposal. Is going off grid the only solution to this?
https://www.onmanorama.com/news/kera...wer-units.html

This could be very bad if they implement it.

Another news item from earlier this year says this applies only to larger systems of over 500kW in capacity: mercomindia.com:8080/kerala-discoms-plea-gross-metering-solar-systems-rejected/

[cgnkar]

Originally Posted by kutts

Very happy with the performance of the plant I installed 4 months back. Now paying 110/- per month as electricity bill, to cover the meter rent and basic charges. Earlier it used to be above 4000/- bimonthly. Statistics included for past 3 months. Plant capacity is 5kw. The <10kw generation per day on couple of days is due to KSEB power shutdown and wifi outage.

Hi,


From the image of the dashboard it looks like you are using Growatt inverter. I've recently (3 months) got solar roofing done but the performance has been a bit disappointing. The power generation is all over the place and dropping to zero often especially when there is good sunlight. The solar contractor is puzzled and the inverter team is coming up with many excuses all of it was fixed but still the issue continues. I don't think I can trust their solutions anymore. So, I was wondering if you will be willing to share some experience with the inverter if you had similar issues and also some generation data for comparison?


I'm attaching generation vs time for comparison.

[kutts]

Originally Posted by cgnkar

So, I was wondering if you will be willing to share some experience with the inverter if you had similar issues and also some generation data for comparison?.

I haven't seen exact behaviour but I did have some hiccups which caused erratic output, hope these help.

Check the electricity board input voltage. The inverter goes into safe mode if either the electricity board voltage or the PV voltage exceeds a limit. I vaguely remember the cut off is at 265v. The solution I used was to switch the input phase to a lower voltage phase. This worked, but you need to have 3 phase connection in order to do this. If all your phases have high voltage then you would need to contact the electricity provider since your household equipment could get fried.

Check for loose neutral and also if all your connections are tight. This is difficult to diagnose and I did a physical check myself since the electrician was too lazy and kept saying it's all tight. In the end, a loose neutral was the culprit.

Are you sure there is no shadow falling on the panels?

Attached are my generation reports for the month of September which had good sunshine, this month which was mostly overcast, two days one with full sunshine and another with rain.









If you are using Growatt it should be okay to contact their support directly. I found the installers/dealers to be less technically sound.

[cgnkar]

Originally Posted by kutts

I haven't seen exact behaviour but I did have some hiccups which caused erratic output, hope these help.

Check the electricity board input voltage. The inverter goes into safe mode if either the electricity board voltage or the PV voltage exceeds a limit. I vaguely remember the cut off is at 265v. The solution I used was to switch the input phase to a lower voltage phase. This worked, but you need to have 3 phase connection in order to do this. If all your phases have high voltage then you would need to contact the electricity provider since your household equipment could get fried.

Check for loose neutral and also if all your connections are tight. This is difficult to diagnose and I did a physical check myself since the electrician was too lazy and kept saying it's all tight. In the end, a loose neutral was the culprit.

Are you sure there is no shadow falling on the panels?

Attached are my generation reports for the month of September which had good sunshine, this month which was mostly overcast, two days one with full sunshine and another with rain.

Attachment 2394458

Attachment 2394459

Attachment 2394460

Attachment 2394461

If you are using Growatt it should be okay to contact their support directly. I found the installers/dealers to be less technically sound.

There is no shading on the panels but when it was commissioned in September there was shading and after 2 months of observation we moved it to zero shade area. I'm puzzled because before moving the inverter never dropped to zero but at the same time peak power didn't exceed 3500 W. The issue started after we moved the panels and mostly I observe inverter going to Zero on good sunny days.

Before moving the panels the peak power was less due to shade and inverter never went to zero but after moving peak power crosses 4000W and often that's when I see the drop. The inverter team claimed it was earthing issue so we got one more earthing done (totally 3 now) after which problem didn't occur for 2 days but it started again.

My doubt is, if the supply fluctuation from the grid is causing the problem then why only on the sunny days I see the issue? The inverter should goto zero regardless of generation power if the supply voltage is the issue isn't it?

Is there anyway to continuously monitor the input grid voltage before it goes into the inverter?

[vj_v3]

Originally Posted by cgnkar

There is no shading on the panels but when it was commissioned in September there was shading and after 2 months of observation we moved it to zero shade area. I'm puzzled because before moving the inverter never dropped to zero but at the same time peak power didn't exceed 3500 W. The issue started after we moved the panels and mostly I observe inverter going to Zero on good sunny days.

Before moving the panels the peak power was less due to shade and inverter never went to zero but after moving peak power crosses 4000W and often that's when I see the drop. The inverter team claimed it was earthing issue so we got one more earthing done (totally 3 now) after which problem didn't occur for 2 days but it started again.

My doubt is, if the supply fluctuation from the grid is causing the problem then why only on the sunny days I see the issue? The inverter should goto zero regardless of generation power if the supply voltage is the issue isn't it?

Is there anyway to continuously monitor the input grid voltage before it goes into the inverter?

The inverter usually displays an error code when shutting down due to any faults. The code can be googled and it will exactly tell you what the problem is.



I don't own a growatt but the app might have details about error codes logged.

To monitor voltage:

1. simple solution is to use a multimeter or voltage meter with display when the issue is happening. but you need to know when issue is happening.

2. For continuous monitoring and visualization there are a bit advanced solutions that you can go diy if you want to monitor all parameters at your mains. I use a Selec EM4M meter and pull data via RS485 to monitor all parameters of power including import, export, voltages and currents and have graphs to visualize whenever i need.

3. Off the shelf products that do similar stuff as the above and come with app eg: Emporia

PS: Apart from the app that the inverter vendor provides. there are ways to pull data from the wifi dongle that is attached to the inverter directly to your pc or more advanced users can also do rs485 communication. For the wifi dongle stuff, you can easily find libraries/integrations that other people have written and you can readily use them.

The advantages of pulling data like this is, you can see more parameters than the app typically shows and if you have the knowledge you can also store these parameters in a db and visualize locally. Voltage will be one of the parameters that you can pull using this apart from error codes.

[cgnkar]

Originally Posted by vj_v3

The inverter usually displays an error code when shutting down due to any faults.

Hi,

The problem to use multimeter is there's delay in data transmission when the issue happens and it is quite random. Monitoring continuously from the grid would be ideal solution. We have LandisGyr net-meter and if I remember correctly it has RS485 port.

Right now, I am not getting much assistance from the inverter side so I'll monitor from the grid.

When the issue happens there is no error code displayed at the inverter. The display from the inverter stays off but the light will be green.

I want to pull the data from our Net-meter, it is of LandisGyr. before raising the issue further I want to make sure with all the data.

Can you please share your DIY solution to pull the data from the meter, I remember there is RS485 port in the meter. I also have Raspberry pi 3b+ and 4 if they are useful.

[Remsoft]

Hello, BHP's,

My house is being built in Chennai, and I have a quote for installing solar panels.

The cost is Rs 2,25,000 for a 3KVA plant, but they will receive TNEB clearance for 5 KVA depending on the usage they indicated, and extra panels can be added.

Please let me know if you recently installed solar panels and how much it cost.

[di1in]

Originally Posted by Remsoft

Hello, BHP's,

My house is being built in Chennai, and I have a quote for installing solar panels.

The cost is Rs 2,25,000 for a 3KVA plant, but they will receive TNEB clearance for 5 KVA depending on the usage they indicated, and extra panels can be added.

Please let me know if you recently installed solar panels and how much it cost.

Attached is a table of cost and subsidy that was available in Kerala in 2022.

Here are some other points that might be of interest based on what I learnt from implementing roof top solar at my home:
1. 250 units/month is the max consumption for value for money from KSEB. If you go one unit above to 251 units, your bill increases by ~₹350. Your states board might have a similar sweet spot.
You can use this to plan for your solar plant capacity, if you can’t cover your whole consumption, at least plan for it to be below 250 units/month or it’s equivalent in your state.

2. If there is partial shade where your panels are to be installed, then connecting them in series will decimate your plant production and also cause hot spots. So plan for this when picking a spot.

3. Partial shade situations can also be caused by over enthusiastic birds pooping all over. Plan for this with Some brands (like Tata solar in my case) offer free cleaning of all panels every 2-3 months for 5 years.

4. Most of our vendors don’t provide this, but they agree it’s a life saver over the long term. solar water drainage clamps can be installed to properly drain rain water from panels, thus preventing stains and dirt collection at lower edges — if unchecked these are the most common cause of under performing panels in rainy areas. These just cost around ₹300 for 10 pieces.

5. Cooler panels are more efficient. Don’t place panels near chimneys or multiple high capacity AC compressors.

6. Monoperc is better (can google this out for your use case)

7. Take pictures of your new net meters readings in the initial months when KSEB comes in for meter reading, and see if values and dates match.

8. Let maids know to not help out by cleaning the panels with a dirty floor mop 😅

[vj_v3]

Originally Posted by cgnkar

Hi,

The problem to use multimeter is there's delay in data transmission when the issue happens and it is quite random. Monitoring continuously from the grid would be ideal solution. We have LandisGyr net-meter and if I remember correctly it has RS485 port.

Right now, I am not getting much assistance from the inverter side so I'll monitor from the grid.

When the issue happens there is no error code displayed at the inverter. The display from the inverter stays off but the light will be green.

I want to pull the data from our Net-meter, it is of LandisGyr. before raising the issue further I want to make sure with all the data.

Can you please share your DIY solution to pull the data from the meter, I remember there is RS485 port in the meter. I also have Raspberry pi 3b+ and 4 if they are useful.

Hi, Firstly let me set some expectations. I am not a pro in all this stuff but just spend time making a few things work based on my needs.

So, similar to your LandisGyr meter, my discom has provided a schneider Er300P meter for netmetering and even this meter has a RS485 port. However, What is important is, the protocol used behind RS485 and having a manual with all the register values.

There are several protocols and my meter apparently uses DLMS. I spend a good couple of months trying you open source tooling like GuruX and also pretented to be a vendor to get the manual from L&T/Schneider. However, no luck. I came in contact with the Schneider Dev team and they denied sharing the manual saying its not for end users and they will provide it only to the purchasing company based on serial number.

i gave them the serial number and they identified that it is owned by discom and straight pointed me to the Discom.

I scoured the internet and found a image of the same model sold privately via dealers. Contacted the dealer to get me the manual etc etc..., they tried their contacts but nothing worked. So, i got fed up and spend Rs 4000 and purchased my own meter for which i can get all the manuals/protocol/register values and installed it just after the discom meter so that it sees everything that the discom meter sees and i can read them and store in a PI/database and visualize.

I looked for a Chint DTSU666 meter but could not find in india. So i bought selec EM4M and was confident that i could read data from it. Both of these use RTU modbus protocol which is well known. you just need to know register addresses which is specific to each brand and comes with their manuals.

Spent some time and was easily able to read via Nodered and then write it to Influx DB. All of this can be done with a PI and raspberry OS. Once you get to this stage, i can share by nodered flows and what i do.

if you have the knowledge or can use the knowledge of the internet effectively to read your landisgyr meter, then thats the cheapest solution. Just try searching your meter model number and if other people have done it you will find it easily. if you don't find anythign obvious, you should search on github directly. I don't have that meter, so it will be difficult for me to research about it or get the interest.

If you don't want to mess with all these diy stuff you can spend a bit more and get Emporia energy meters on Amazon india. they have an app and you can visualize without any efforts. Lets me know if you have any questions.

[satnan]

We are considering a solar off grid plant for our new house which is in final stages of construction:


I assume the total consumption by all equipment's on inverter line to be about 3.5 kWh per day

- All lights (approx 0.8 to 1 kWh per day)
- All Fans (approx 1- 1.2 kWh per day)
- Refrigerator (I am not sure of the daily consumption, but will assume 1-1.5 kWh per day)
- Washing Machine (approx 0.5kWh per day)
- Wet Grinder (negligible)


Following will be on main supply and not on inverter line (In good sun light, we may consider using the Iron box / Mixer etc on the inverter line though).
- Geysers
- ACs
- OTG, Microwave
- Iron box, Mixer etc



I am planning to get a Solar PCU of 3.75kVA and 4x150Ah batteries. Most of the standard, off grid systems have solar panels rated 3kW (say 9x330W) to go with this, but my plan is to get only 2kW panels (say 6x330 or 5x440).

My calculation is as follows:

4x150Ah batteries can hold 150x 4 x 12 = 7.2kWh

of which about ~50% will be usable = 3.6kWh. I would like to configure the inverter to switch to grid once battery power is about 60-65% of the full capacity so that remaining 10-15% is available if there is a power failure. Battery charging to be configured only on Solar.

On sunny days, I expect approx 8 kWh power generated from the 2kW panels and unless I have good day time usage, I guess I would still be wasting lot of generated power as battery cannot take all that power (I can also consider 200Ah batteries to increase the storage capacity further). Hence the idea not to go with 3kW panels and limit to 2kW only (may be I should go down further to 1.5kW?)

Did I make any obvious mistakes? Anything overlooked? Is this looking like an efficient system? Would be very happy to hear feedback and suggestions from experts here. Thanks much in advance

[deep_bang]

Originally Posted by satnan

We are considering a solar off grid plant for our new house which is in final stages of construction:

Your calculations are reasonable but only question is on why off-grid. Grid tied systems have one big advantage of not having to worry about storage.

Charging/discharging the 150ah hour batteries everyday may make the batteries last only for 2 years (assuming 720 charge/discharge cycles). So every 2 years (or say 3 years) there will be a recurring cost of some 40k (assuming each 150ah battery Costs about 10k). Assuming you generate and use 5kwh every day (some part may be directly used without storage and say 3.6kwh is what you use out of the battery), that means in 3 years you generate and use 5475 units. This saving more or less negates the cost of battery every 3 years. Have you considered it this way and still want to go with an off-grid system?

Also, I am not aware of whether inverters can be programmed to switch over from battery to grid at a certain percentage of charge - I assume you have ensured the availability of such inverters.

[ColAjayDrives]

Originally Posted by vj_v3

Don't see a PM option. I had a vendor contact for Tata from a friend who got it done recently but still decided to go to https://www.tatapowersolar.com/contact-us/enquiries/ and send an enquiry.



The vendor working on mine is Kehan sri solar (I verified that they are a empanelled vendor from the list on TSSPDCL website). However, i am still not at the stage of recommending them since mine is still in approvals and i haven't seen their work on the ground yet. May be i will have full feedback in 2 months from now.

.

Hi VJ,
Did you get to finish your installation?
If yes, can you kindly share vendor feedback and contact details pls.
TIA

[vj_v3]

Originally Posted by ColAjayDrives

Hi VJ,
Did you get to finish your installation?
If yes, can you kindly share vendor feedback and contact details pls.
TIA

Isha Solar - Naveen - 73863 79910 - not sure about subsidy but smart guy and will suggest best system

Sri laxmi energy systems -Vikram - 6309 861 344 - sales guy from kehansri, moved out now.

Kehansri solar - Desk - +916309296760 - lost all their people, did a average install at my friends place recently, while mine is ok,

Cherish solar - +919845878643 - Was looking for hybrid inverter and got this contact, they deal in adani high w 540W i think subsidy approved panels.

Try to talk to all to get an idea.

I don't seem to have PM rights on tbhp yet, so unable to share my contact. happy to talk through.

Condition for subsidy: (frankly, can ignore subsidy if you want the latest system, wont cost too much more in reality)

- DCR approved panels. search for ALMM list 2022 on google
- purely grid tied system only, hybrid and offgrid does not get subsidy.