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So, my vendor told me that as I have opted for the subsidy, BESCOM will pay 2.90 or so a unit. He also said that it wont directly offset my fixed charges but will be paid into my bank account every 3-6 months.

Are you sure you are getting the fixed charges directly offset? And, if you are getting 4/- per unit, did you not avail the subsidy?

Also, have been quoted 7.75 lakhs for a 10KW unit. Does that sound reasonable? It's with microinverters.

Let me look at the bill and get back to whether they are offset directly in the bill or whether they are.offset as they get paid into my account. One of the reasons I am wary of the accounting is that it's all manual and it's very hard to understand and more over I don't even get a bill every month. That's why I was cautioning you (since you seem to be from Bangalore) not to over invest in capacity but just invest enough to offset your usage.

I did not avail of the subsidy as I was not sure how long and how hard it will be to get the same. If you are able to get the subsidy, go for it and plan to just offset your usage. I doubt that fixed charges can go so high as being discussed above - so my take would be to plan for a little more than your usage and if ift offsets your fixed charges, that's good, else don't worry too much about it. Don't over invest is what I am saying.

Thanks makes sense. I went with 10 as a friend told me thats what he had ordered but now will check what his bills are as compared to ours. Would be grateful if you could check your bills and let me know.

A manual bill, and not even getting a monthly bill sounds like a recipe for disaster and arguments with BESCOM.

I installed mine through Tata Solar, and my cost was around ₹45,000 per kW. I took 3.5kW and got a bill of around 1.58L. Subsidy reduced it to 1.28L for 3.5kW. (Structure costs were an additional ₹38k). These are not microinverters. I had a Reddit discussion then, and most were of the opinion that the benefits of microinverters are real, but the RoI isn’t good enough so far. Perhaps when they get less expensive.

My Tata solar system produces around 14 units a day on average throughout the year. Peak production in March was 533 units. And lowest production was in July (monsoons in Kerala) 331 units. This year, it’s generated 3.35Mw so far, so averaging 446 units per month.

I believe that to get better RoI, a better goal is to aim for just enough to cover your projected highest monthly consumption rather than over producing too much. We have the telescopic slab system for power, so the cost per unit goes up the more you consume.

Your projected highest monthly consumption should account for any electric car or bike you intend to buy.

State Electricity Board is supposed to pay excess units exported at the agreed tariff at the end of each settlement year. Are they not following it in Punjab?

The state electricity board resets the clock to zero at the end of the settlement cycle. The concept of "banking" exists only for months within the settlement cycle.

In bangalore they pay for the excess generated with money to account monthly. Not carried forward.

I had a chat with the solar guy today. Got to know a new thing.
Interestingly, in Punjab, if the excess units injected to the grid (in the settlement cycle) exceed 100% of the household consumption, then not only are the excess units not carried forward in the next cycle, but 10% of consumed units are charged back to the house :Frustrati which is absolute bonkers!
The household loses on excess electricity units generated and is also penalized if it produces too much clap:

PS: No money is ever credited to anyone. Only units are "banked" for next month forward till the end of the settlement cycle when even the carry forward is reset to zero.

All the more reason to get an electric car to eliminate the fossil fuel expenses!
Plus, I understand Punjab Govt is also not levying road tax on EVs.

1. There are many Indian brands - Tata, Adani, Vikram, waaree to name a few. You can view this link to get an idea of manufacturers and panel models that are eligible for subsidy. However, there are several other international panels that are not covered in subsidy scheme but many vendors offer pricing close to subsidy pricing for non subsidy solar plants as well. Subsidy vendors will push for 335w polycrystalline panels since its cost effective for them but for best space efficiency it is best to go for the highest available Wattage panels which are usually Moro perc or bifacial. While most of these companies manufacture panels, Inverters are mostly chinese. Many indian brands also sell rebranded chinese inverters.

Also, Please note that grid tied systems are always without battery backup and shutdown completely when there is a power cut. And subsidy is applicable only for grid tied systems.
For battery backup, one needs to go for Offgrid or hybrid systems which are much more expensive than pure grid tied systems. With hybrid you will have solar generation when there is a powercut as well and can also export to grid when generating excess.

2. To know how much solar plant capacity you need, you need to gather your bills for the last 12 months. Sum up the units and divide by 1440 to get approx plant capacity. On an average a 1kw solar plant generates about 4 units a day (atleast in hyderabad). Please note that this is just the yearly average and not guaranteed 4 units a day. Summer months will be higher, rainy months will be lower.

3. On an average, each panel measures slightly above 2m x 1m. As an example, if you get a 5kw plan with 400w panels. you will need about 12 - 13 panels. So, the roof top space required will be about 350 sq meters. The panels are installed at an angle facing the south direction. East, west and south of your house should be shade free at all times of the day for best generation. if you have high rise buildings around your house, it might not make much economic sense. Microinverter based systems make best sense in partial shading scenarios
where you can install different sets of panels in different directions to make best use of the sun when there is no shade.

4. mostly answered question 4 in point 1.

Related to some other discussions above about settlement etc. Just posting some details for Telangana and more details about my solar plant.


- The year is split into two 6 month periods. Jan to June and July to Dec. Excess units generated in each of these periods are carried forward to the next months and adjusted against your unit consumption in those months.

End of June and Dec, all excess units still left are 0'd out and settled to billing account as per PPA for the year. about 4.30 Rs this year.

Minimum bill is adjusted against the Settlement amount available in your billing account. For example. I have about 6000 Rs in my billing account through settlements in the last couple of years and i pay 0 bill and my minimum is adjust from the excess balance i have each month.

i bought an EV in Feb, so for the first time in 2 years, this july (mostly due to rainy, cloudy weather), my units consumed exceeded units generated by about 200 units. Since previous units were also settled end of june, there was no excess units balance to offset against in july. Still i paid 0, because i have 6000 Rs balance in my billing account.

Thankfully, there is no per kw min charge per month in telangana as of now. its just a flat fee of about 280 per month for a 3 phase supply.

i am using a 7.2 kw charger for charging my ev and this usage is over my contracted load of 6 kw. TSSPDCL is still kind enough to not penalize... I am staying away from increasing contracted load (although its just a flat one time online fee of 1600 Rs per KW increase and no other additional chai pani required) to avoid a situation where they suddenly introduce a per kw fee and i am in soup paying monthly charges for all the KW i have contracted.

I though about all this and got a smart OPENEVSE EV fast AC charger instead of the locally availanle ones. The openevse has excellent opensource software and if fed with energy data from your meter, has the capability to adjust charging rate according the rest of the consumption of your house. With this feature, i can configure it to always keep my overall instantaneous consumption below my contracted load if the DISCOM gets nasty.

The OPENEVSE can also follow my solar generation if it is fed with solar data in which case you can do crazy things like charging you car with purely green energy if that matters to you. I am a bit into IOT as a hobby, so have all this energy data collected already on my home automation server.

OFFTOPIC, i initially got my solar plant under the subsidy scheme from TATA power and it came with a Goodwe grid tied inverter.

Since i am crazy, Although Not very cost effective, i went ahead and purchased a Hybbrid inverter and LFP battery pack separately and now have my solar panels connected to the hybrid inverter and my original Goodwe inverter is now shutdown and wrapped in polythene. I have installed the hybrid inverter just beside the original inverter and have done separate wiring for it so that i can just swap the solar panels to the original inverter and show the hybrid inverter as a isolated backup inverter only if someone does show up for inspection in the future. (Although, i dont think anyone would)

If i ever have to add more panels to cover for increased consumption, i can happily add those panels to the inverter that is sitting idle as of now. So i just need to procure some panels and get them installed on a new structure and do the wiring myself since its simple enough. Until then the inverter sits as backup.

I also considered selling off the old grid tied inverter but its not much money and i'd also like to watch out for any inspections for a year or 2.

The advantage with the hybrid inverter is offcourse that i have power all the time and can technically go fully offgrid if i have enough battery backup. have 5 kw right now (and might work on building a 5kw pack additionally if i get hold of proper LFP cells) and for my critical loads like fans, lights etc this can last over 12-15 hrs happily. My inverter has an additional output apart from critical load output and i have wired it in such a way that if i flip a 2 way mcb, i can power the whole house including AC's when solar generation is high during the day.

Did you consult with Tata Power before switching to a hybrid inverter? It might cause warranty issues later.
My contractor told me there might be an inspection after installation but no one came in the last 2 years. I had asked them about changing to a hybrid inverter but they were hesitant, saying hybrid inverters don't perform well. (Didn't explain on this though). Since they had 1 free yearly maintenance service, didn't want to mess up with the installation.

This sounds like the discom never wants you to export?

If they don't want you to export, there is a concept of zero export on most inverters. check manufacturer documentation... it usually involves installing a ct coil that is placed just after your meter and connecting it to the inverter. The inverter will then know if power is being exported out and will reduce generation to keep export 0

Why will i consult them when i know that they wont agree? I have done completely separate wiring for my Hybrid inverter. The original grid tied inverter is still in its original place wrapped in a cover and turned off. If someone really wants to ever inspect they will have to wait until i am able to swap the panel strings from the hybrid inverter to the grid tied inverter which is a 2 min task for me. if i am not at home, no one gets access to my terrace.

Hybrid inverters not performing well has no logic to it. In fact, i am a very data driven person, so for 2-3 months i connected half the panels to the hybrid inverter and left the remaining half on the grid tied inverter to compare performance. Almost everyday the hybrid inverter would generate about .5 to 1 unit higher than the grid tied inverter.

When the need arises, i will add more panels and connect it to the idle inverter but for now its at rest.

My TSREDCO inspection was done within 6 months of installation. if no one visited you for installation, it means the official has a setting or trusts too much in your vendor and signed the documents directly.

The vendor is paid the subsidy money only if inspection is complete, so i am sure the vendor won't let go so easily and already got it signed. There are portal to check status of all those things if you have the order number details etc.

Embarking on the solar power journey was initially met with skepticism, especially for our new house construction project. However, my father-in-law's interest led us to connect with someone who had successfully implemented solar power in their home. After meeting with him and gaining insights into the system's functionality, he shared the contact details of the company responsible for their solar panel installation.

Promptly, the company owner visited our site, providing a detailed explanation of the solar power installation process. Simultaneously, I delved into online resources, particularly YouTube videos, to enhance my understanding of this eco-friendly technology.

Upon receiving a quote from the company, we were pleasantly surprised to find them accommodating our construction timeline, agreeing to commence the installation four months later. The installation aligned with our specific requirements, and the subsequent wait of 3 to 4 weeks for the EB inspection felt like a worthwhile anticipation.

The turning point came with the installation of the bi-directional meter on June 1st, 2023,:Cheering: marking the initiation of power generation. Now, let's explore the cost savings achieved through this sustainable venture.