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I have installed solar in my rooftop (this is in Coimbatore). TNEB officials informed that hybrid inverters are not allowed as it is riskier for linemen. Didn't argue any further, went with on-grid inverter.

On-Grid doesn't produce any electricity if the Electricity Board Transformer is down. So Off-Grid setup will be good for you if load-shedding is frequent. But it will be more costly.

Regarding the bill, unfortunately, the bills will be separate even after being in 1 person's name. Also, do remember, the excess generated and set-off against the consumption from the grid happens with Net-meter, but you cannot carry forward the negative balance or even get credit for the negative balance. Speaking from experience of our own unit in Baramati. Hence, the higher the KV generated, it will not give any benefit unless you consume all of the negative balance till 31st March.

Hence, on-grid is not suitable for you for these 2 reasons.

That's all I need to read to know that it is a gamble. Whatever the service or commodity.

I originally got an ongrid system installed 3 years ago and an year later swapped out just the inverter with a hybrid and did separate input and output wiring for the hybrid inverter.


The ongrid inverter sits in its place wrapped in plastic. If someone has to check on it ever, I have the option to just switch solar panel wires back and show it to them and the hybrid inverter will look like an independent setup hooked to a battery pack. It's significant wastage of money for new installations but I did what I needed.

To prevent leakages etc due to improper wiring/ common neutral that electricians do, I have a selec VPR hooked to a contactor installed at the edge of my grid connection after my meter. Whenever there is a power cut, the vpr will turnoff the contactor and isolate my home completely from the grid automatically.

Offcourse the vpr is originally designed to protect the home from voltage surges etc as well.

If anyone needs more details and know some basics, I can share pics and more details. I do a lot of diy in this space. regular electricians do not understand any of this, so they cant help much.

Can you pls explain what a "VPR" is and how it helps and how to install, and costing too. Photos will be educative too pls. TIA

I wanted to do similar but was discouraged by Installer fearing his license. The reputation of this dept precedes itself.

This is very interesting set up. Please do share. Tech savvy folks will benefit.
Checking is a concern though.

VPR is Voltage protection relay. specfications here. It basically has a bunch of features, voltage under over protection, frequency, phase assymetry, phase failure and phase sequence monitoring. Many of these features can be disabled based on your requirement. For example, phase assymetry, sequence etc matters only for 3 phase appliances like elevator motors and 3 phase water pumps etc. The point is the VPR does not correct any of these defects, it just turns ON or OFF the relay if the parameters do not match. The relay is used to drive a contactor.

Neither my installer, nor my discom knows that i have a hybrid installed. Frankly, most installer don't even care and will mostly be waiting for their 5 yr support contract to end. The local discom folks don't bother to come and check unless they see somethign weird happening. MNRE folks probably don't have the bandwidth to come and check back ever. My hybrid setup has been this way for almost 2 yrs now. my solar setup is fully on the terrace under the over head water tank and only the input/output wires come down to the ground floor at the meter.

I called the solar installer once to fix a failed SPD. i just switched my solar panel cables to the ON grid inverter they supplied before he arrived and switched back after he did his stuff. He asked about the hybrid inverter, i said only 1 line - "its my UPS and is a separate setup."




Follow the green arrow in the picture above.

The first part is just a bidirection modbus meter from Selec. its in series with the DISCOM meter and essentially sees the same inflow and outflow as the DISCOM meter. Since i cannot digitally read data from the discom meter, i installed this meter in series and pull data from it for monitoring.

The 2nd part is the selec VPR900. If i remember correctly, i have disabled al the phase and frequency monitoring features and just have over-under voltage configured. the VPR is powered by 1 of the phases of my grid connection, so if the grid is down the VPR is down and my home is completely isolated from the Grid. More about that in the next paragraph. The VPR costed 1000 RS i think.

The 3rd part is a schneider 4 pole contactor. The contactor coil is driven by the VPR relay. If the VPR relay is ON, the contactor coil is energized and the contactor input poles are connected to the output and the home is connected to the grid. When the VPR relay is OFF, the contactor coil is deenerguzed and the home is isolated from the grid. This contactor is a 40 Amp one and probably costed 1500 but this is a old pic. I am using a EU controls 63 amps 4Pole contactor now which also cost 1500 i think.

The red, yellow, blue, black blocks next are just industrial terminal blocks for distribution. In most solar installations, the solar Input/ouput is directly connected to the discom meter. that is because most homes don't have a distribution block like this after the discom meter to terminate the solar wires.

I have a 6kw deye hybrid inverter and 5kwh LFP battery pack. 6 kw solar panels. The inverter has 2 outputs, 1 called SMART loads and the other called critical loads.

I use the Critical loads for all UPS points at home like lights, fans, cctv, computer points etc. These are all about 600 watts of load.

I rarely use the SMART loads output but i currently sometimes manually switchover (using a change over switch shown in the image) my whole house onto the Deye inverter when there is a long power cut during the day. I have automations to keep super heavy loads like my central geysers from turning on when grid power is down.

Below is the full picture of my distribution panel. I will not explain the whole thing right now unless someone want more details. There is an additional meter to measure what is going into the home and one more meter to see what is going into my EV. It's still work in progress, i need to organize better and change a few things to be able to remotely/automatically switch my whole home onto the hybrid inverter when the grid is down and its day time when solar is able to generate energy.



Below is an image of my Home assistant energy dashboard which gives me full visibility into how much energy solar is generating, import, export, how much the home has consumed vs the battery pack. The first image is kwh details for the day, the 2nd image is realtime instantaneous usage dashboard.

I sincerely wish I had a neighbor like you to guide on this. This is industrial level wiring and planning. Loved the neat labels and tagging.

Since I don't have support from installer, I was just wondering :

1. Can I have a manual DC switch that will route between an hybrid inverter and on-grid on demand (e.g. natural calamity) after switching the mains off from grid ?
2. If yes, will it need messing around with the existing DC wiring which is plugged straight from panels ? Can I extend DC input from the DC tripper from DC-DB box ?
3. Nowadays, battery-less hybrid inverters are being sold, is that an easy way out for non-savvies ?

1. You can switchover the panels from one inverter to another using a change over like this. Ensure voltage/current of your solar panel string is below the specifications of the changeover. It was hard to find, i needed 2 but bought 1 first to test and never tested. Looked everywhere and finally found it here




For how rarely i need to change the cables, i felt it was easier to just swap cables than to install the changeover, so i left that as is. And also if you install the changeover they will know that you are switching between the inverters etc. still feel its easy to convince and they wont care but unnecessary complication.

Note: never changeover on the fly when Solar is generating energy. these high DC voltages are extremely dangerous and can kill you instantly. Abrupt changeover causes DC arcs which can belt terminals and cause fire. Everything should be safely shutdown and then changedover before turning back devices ON. If YOU DO NOT KNOW WHAT YOU ARE DOING, DON'T DO IT.

2. If you install a changeover like this, you would can unplug the DC cables coming out of the DC db, plug it into the Input of the changeover and get 2 outputs out from the changeover that will connect to the 2 inverters.

If you have 2 strings, you will need 2 changeovers.

You will need a few sets of mc4 connectors, some dc wires, mc4 crimper etc to make the extensions. All these are easily available.

3. I guess you are talking about hybrid inverter that can start using just solar energy (no grid and no battery). I feel this is a bit of a gimmick since you will not be able to use the energy consistently. For example, the inverter will trip when there is cloud cover, or when you turn on a load that is trying to draw more current than solar is generating etc. So, IMO - its a good feature to advertise but will not practically help much in real world scenarios.

Basically, this is the same switch we find in the shops which switches between the electric supply from the EB and the generator. Correct?
I'm also planning for a 3.3 KW On Grid System but wanted to tap in the generated power when there is load shedding or power failure during calamities.

I don't have experience with generators but you can get ATS for Automatic generator/grid switching.

If you do not want automatic, you can get a manual change over like the 1st like right most component above.

Any feedback Deye inverters / batteries in terms of service and warranty support and reliability? I am coming across Deye in many places but I am unclear how good they are.

No service experience on the hardware side yet since it has been working fine. However, for now i have contact details of Deye India sales head and hope they will provide reasonable service. I also bought the inverter directly from the distributor.

On the software support side, i was able to write a mail to deye cn directly and they did a software update remote. The funny part was they did it without coordinating a maintenance window and the software update triggered a reboot of the inverter. I suddenly lost power and had no idea what happened. they conveniently replied back to my email that update is done 10 mins later.

That said, Deye inverter are very popular worldwide and are extremely robust. dozens of brand inside and outside india sell rebranded deye inverters. Some that i know - sunsynk, ksolare, cellcronic, loom solar, Invergy.

I have seen another brand called luxpower being sold in india in the last 1 year.

Youtube channel called Khalsa Electricals is a good reference to see hybrid inverter brands. he mostly does hybrid installations, so you can get a good understanding of how things work.

Hi Guys,

Just got our 7kw unit installed. I saw that for example today it generated 31kwh but the net meter said that feed to rid was only 17kwh.

Is it that we consumed 14kwh and only the excess was sent to the grid? I thought all generated power goes to grid, and what we consume comes from the grid and then the net usage/excess is calculated? I presume this is wrong and only surplus after consumption gets sent to the grid?

Yes correct. Only the excess goes to the grid after covering for household consumption. Also, remember you will still be using power after the sun goes down, so your total grid export will cover your usage beyond the solar production hours.