[Thilak29]

Prelude

2020 was dramatic, to say the least. I had an episode (Miscreants assault me & damage my car (EDIT: accused now in police custody))with a rogue element on the street and fellow BHPians were more than willing to offer all possible support.

Then Covid happened, Bangalore was no longer a base and I moved my work and family to my native home. Life changed in various dimensions and quality of living improved significantly thanks to good food, active routine, clean air/water.

The Internet and Power situation was manageable to meet work demands.

The Internet situation got stabilised with 4G modems and eventually a herculean effort to bring broadband from a place four km away by collaborating with a few who too had moved out of Bangalore and chose to work from home.

UPS at home gave just enough backup to manage 8 hour-long weekly power cuts and anything beyond was difficult. I added one more inverter battery and that brought good relief. I even bought a Belkin laptop charger that can be hooked to a 12V port within the car, just in case power cuts are too long.

Naturally, the electricity bill took a sharp upswing with more electric items in use by more people (two to seven increase) at home.


Power Generation thoughts :

Power generation at home was the next conceived thought. Many suggested using generators and I enquired with a local Honda dealer who promptly gave a cost estimate for the product (https://www.hondaindiapower.com/product-detail/ep-1000) and installation. Somehow, I was not convinced that this was a sustainable long term solution.

Let’s go Solar :

I continued my reading and Solar seemed a viable option but the upfront cost seemed high when compared to compact generators.

Solar options :

Based on my research I found the following PV electricity generation options.

• On-Grid Solar
• Off-Grid Solar
• Hybrid System

On-Grid: On-grid means solar PV system is tied to the local utility's grid. The power generated is offered to the home first and any excess is sent to the grid. At the end of the billing cycle, net power is calculated as power drawn from the grid/sent to the grid. Also, this means that the utility system acts as battery space without extra cost when generation is higher than utilisation to be used when solar is not/less generating. This is the least expensive option as fewer components are involved in this setup.

Off-Grid: Off-grid solar systems have no connection to the utility grid, and this must be designed to produce all the electricity necessary to power your needs. Off-grid solar systems operate from the stored energy in a battery bank. Solar panels generate power to charge the battery bank. The overall cost is proportional to one’s power needs and battery banks usually require periodic maintenance.

Hybrid: This yields the best of both worlds and is expensive among the lot. In this setup, systems generate power in the same way as a common grid-tie solar system but it uses batteries to store energy for later use. This ability to store energy makes most hybrid systems operate as a backup power supply while also sending excess power generated to the grid.

How did I assess?

Cost :
I set my budget and I was not keen to spend on batteries which eat space and require periodic maintenance for a long life. I then did some break-even calculation factoring time value changes and it further reassured my decision to opt for Solar.

Power consumption :
I took billing figures for the last 12 months and arrived at the max power consumption number and then did a bit of future-proofing calculation to arrive at 4kW capacity.


Potential for power generation :
At the budget set, I felt the OnGrid system can yield the best outcome, however, the OnGrid system works only when the grid offers a power supply (this prevents return supply to the grid when the line is under maintenance and further any unwarranted fatality). While there are power cuts on a regular basis, it is not that bad and I was fine letting go of some generation due to the same since the benefits outweigh.

Solar panels are placed south facing for best results and I observed that there are no shadows causing trees in that direction. A couple of years ago we erected a mud tiled roof to cover our entire terrace and I felt placing panels on this tiled roof can be somewhat challenging.

Choosing installer :
I Googled to list some of the local installers around. I spoke to most of the listed ones and tried to understand their expertise, offerings, attention to details paid. Some showed interest and provided quotes on short notice, many did not bother to follow up or provide quotes. I shortlisted three installers, two small-timers (multi-brand offering) and one reputed engineering company tied with Tata Solar.

This engineering company was responsive initially but when I mentioned the tiled roof they developed cold feet and began giving procedural responses like, they are consulting Tata Solar on the structural design. I waited for a few days before my patience ran out.

Then I liaised with one of the two small-timers based on the response received and I invited him to visit the site to make an assessment and offer a quote.

Choosing a panel :
Essentially, there are two types of crystalline silicon panels mainly. Monocrystalline silicon offers high efficiency and good heat tolerance characteristics with a small footprint. Polycrystalline (or multi-crystalline) silicon cell based solar panels are the most popular choice in residential installs though. I chose Mono and it is more expensive than poly and I felt premium paid is justified considering the benefits offered in terms of panel quality, energy efficiency, temperature tolerance and overall durability. I went for Vikram branded one, 10 panels with each 400Wh capacity.


Choosing inverter :
This is a key component of the system. There are a couple of types of inverters one can choose from :

• String inverters
• Power optimizers
• Microinverters

String inverter technology has been used for decades. It is a very reliable, tried-and-tested technology, string inverters can only optimize power output at the string level, not at the individual panel level. DC to AC conversion happens in a centralised manner. This sees a drawback as the production gets averaged out if one of the panels malfunctions or gets into the shade. Also, panel-level monitoring is not possible in this option. However, this is the cheapest option to go with.

Power optimizers are devices located at each panel. However, instead of converting the DC electricity to AC electricity at the panel itself, they just optimise the DC electricity and send it to a string inverter. In scenarios where your roof is shaded, the panel level optimization by power optimizers results in higher efficiency than using a string inverter alone.

Microinverters are installed on each individual panel in a solar panel. They convert the DC electricity from solar panels into AC electricity on the roof itself, with no need for a separate central inverter. They also allow you to monitor the performance of individual solar panels. This happens to be an expensive option among the three.

I chose Enphase branded micro inverters which communicate to a central console called Envoy and allow monitoring through mobile/web.


DISCOM Formalities :
While I was scouting for an installer, I initiated a formal application process and surprisingly the caseworkers were very cordial. Once the installer came on board, I let him handle the office runs who duly did despite the long commutes involved. This is a long detailed process, involving a couple of site visits by officials too. Finally, an agreement is forged with DISCOM to purchase electricity at an agreed rate for the fixed term.

Subsidy Ordeal :
Installer and caseworkers at DISCOM were insisting that there is no subsidy for setting up rooftop solar setup. However, my reading in MNRE, KERC, KREDL and MESCOM sites clearly mentioned subsidies being provided. However, each pointed at others to offer a subsidy, a classic case of bureaucratic chaos over policy details. I filed RTI to MESCOM (as they were my touchpoint) and they sent voluminous documents which were completely unrelated to my queries. I filed an appeal and MESCOM MD sought a VC call with me and instructed his team to provide their formal response after a detailed study, finally they provided a written response stating they are not liable to offer any subsidy irrespective of what the rest of the agencies suggest.

Commissioning :
The process of setting up the overall system is a detailed time-consuming process. Installer offloaded most of the material upon upfront part payment. They began structural work and ended up breaking a few mud tiles in the process too which got replaced. Once panels and micro-inverters were connected, wiring and setting up a new metering system, ACDB was done in phases. Finally, the Envoy module was synchronised and production started. I have connected Envoy to the internet and on real-time basis production status can be monitored with a clean dashboard. Their tool also lets you troubleshoot and narrow down the root cause in case production is low/null.


Hiccups :
Supply voltage turned out lower than the operating range set to microinverters, this key detail was missed during the entire process and I felt disappointed and feared the entire investment will turn futile now. I spoke to the local JE and lineman who suggested shifting to another service line that has a significantly lower load and voila changing line solved this problem.

Enphase microinverters have something called grid profiles, they are essentially the operating instructions for these devices in varying conditions of voltage and frequency. The default one set seemed too sensitive to varying grid conditions impacting production. Enphase thankfully has a forum where users interact and moderators support with answers and a friendly moderator from Kerala helped me to narrow down into three specific grid profiles and at the moment one of them is rolled out and under observation. Ticket based Enphase support also appears effective and they are able to access my solar setup remotely and make necessary changes to optimise production (if needed).



What next?
It's been a couple of weeks since the setup is complete, I am closely monitoring production and trying to understand various parameters involved which impacts production (AC voltage ranges, frequency stability, Cloud being key ones), it has been quite a learning journey and I am happy with the outcome and hope that it will stand the test of time.

Brio (aged 9 years with 90k on odo) and Figo (aged 5 with 80k on odo) are my current rides. Usage has significantly come down and most runs are short in nature. I wish to replace one of my two cars with an EV in the next 3-5 years when there is a reliable offering with a decent real-world range (350/400 km).

If Honda offers an electric Activa, I will be in line to buy one too!
Ather in its current pricing is not that attractive for rural riding. Let’s see what Ola has to offer.

Thanks for reading, happy to answer should there be any queries.

[GTO]

Thread moved out from the Assembly Line. Thanks for sharing!

Will go to our homepage today .

[SmartCat]

Tata is advertising solar rooftop power solutions a lot on Youtube and TV
https://www.tatapowersolarrooftops.com/

https://www.youtube.com/watch?v=-fimthN8kHs

[pandey.jai]

This was a very interesting read first thing on Friday morning. Thank you

Some questions:

• How long did the entire process take - from the initial idea to the final set up?
• What was the overall cost for this set up? And how long do you anticipate you will need to break even?
• What is the claimed lifespan of this set up? Is there a likelihood of some parts requiring periodic replacement/maintenance?

[saikarthik]

Thanks for the detailed writeup on explaining the complete selection and installation process. Apart from the questions @pandey.jai asked,

• Is there any insurance offered by some agency on damage for these installations considering the cost?
• How frequently does one have to clean the panels for keeping the efficiency high - depending on dust in your place for example?
• Since these are multi-brand integrated products, who is covering warranty for the system level?

May be in a couple of years when I settle down in one place, I would like to install a solar generation unit in my place. But will start with 2 KW and scale it up. That brings me to the main question - how easy is it scalable once installed?

[honeybee]

Thanks for the excellent writeup. It explains a lot about the process before the system is commissioned, an often neglected part.

Apart from the total cost and the break even, what is the power being generated on an average? In layman's terms how much excess at peak?

I am assuming since this is an On Grid type, all electricals in your house are powered by this setup.

[srini1785]

That's a very interesting read. Obvious questions are the following.

1. What does the overall set up cost?.
2. What is the generation capacity in terms of KWhr?.

Its the first time I am seeing an actual on-grid installation. I have always assumed that solar power plants need a battery bank and are off-grid. So an eye opener for me.

On subsidies, I think that none of the distribution companies would subsidize capital expenditure. They will only offer a power purchase agreement. Its the same whether its solar or bagasse based co-gen plant or any power plant that sells its power to state distribution companies.

[Chillout]

Thanks for the detailed write up, I am also looking for Solar energy to reduce the growing electricity cost and a city like Chennai has abundant sunlight throughout the year.

As others requested if you could give the breakup cost for panel, inverters , wiring etc, it would be useful. Also looks like you still haven't figured the perfect grid profile

[akash.1318]

Yup, We're going renewable too.!! The Grid-Tie way

Having trouble choosing a good Grid-Tie Inverter, A "Smart" one which I can monitor through TCP/IP is a must for me. Currently leaning towards GoodWe/Growatt/PowerOne(You can only chose from the companies that are empanelled with/from BESCOM)

Sanctioned Load - 3KW
Contract Term - 25 Years with BESCOM

Some pics of the process








More details to follow soon.

[AZT]

Originally Posted by Thilak29

Thanks for reading, happy to answer should there be any queries.

How often would you need to clean the panels for dust and crow mess. Can you do this yourself or will need to call in professionals.

[jothishX]

Originally Posted by akash.1318

Currently leaning towards GoodWe/Growatt/PowerOne(You can only chose from the companies that are empanelled with/from BESCOM)

Two of my colleagues are using GoodWe grid tie inverters (3 7 5kW) since last two years without any problems till now. They had mentioned that most of the grid tie inverters are made-in-china only but are better quality

[maddy42]

Congrats on this setup and i am currently on the fence for something similar but the vagueness in costs and no one in my area having setup done yet.

So yours is a on grid system? Will the constant power cuts reduce your revenue? Also whats the cost of your setup?

Maddy

[Thilak29]

Originally Posted by GTO

Will go to our homepage today .

Wah! I am honoured.

Originally Posted by SmartCat

Tata is advertising solar rooftop power solutions a lot on Youtube and TV

Seems like just another Tata product with a good marketing push and possibly reliable /well-engineered one, but those on the ground aren't keen to sell.

Originally Posted by pandey.jai

Some questions:

• How long did the entire process take - from the initial idea to the final set up?
• What was the overall cost for this setup? And how long do you anticipate you will need to break even?
• What is the claimed lifespan of this setup? Is there a likelihood of some parts requiring periodic replacement/maintenance?

- The entire process took about 3 months and DISCOM formalities is a key reason for longer delays, then some delays on the installer side since he operates with limited capacity at multiple sites at a given time. I felt if Installer can manage to get the full team on the job it is a matter of 3 days at most to set the entire thing up and running.

- For me, cost hovers around 2.8L and the break-even period for me is about 6.3 years, however, if I shift to EV sooner it would offset significant fuel cost and breakeven would be even sooner. Breakeven calculation is very much tied to individual power consumption needs.

- I am told it would last 25 years by many (in fact even my contract with DISCOM is for that period) but I feel that being stretched expectation, I am happy if this remains reliable for the next 15 years. There are no moving parts whatsoever, there are electronic components in the inverter and communication module which may fail due to extreme surges. However, some of the reviews on Youtube suggest, Enphase products are extremely reliable. Solar Panels may crack needing replacement, also damages due to hailstorm is a fear deep inside. The only maintenance is keeping the panel clean on a monthly basis with a water jet.

Originally Posted by saikarthik

• Is there any insurance offered by some agency on damage for these installations considering the cost?
• How frequently does one have to clean the panels for keeping the efficiency high - depending on dust in your place for example?
• Since these are multi-brand integrated products, who is covering the warranty for the system level?

how easy is it scalable once installed?

- I have not pursued insurance yet, but I know HDFC and ICICI have products covering such installation.
- Purely on dust situation at one's place, if its too dusty weekly else once in a month is sufficient.
- Warranty is at the component level, no system warranty is given. Panel and other component have their own warranty promises.
- Scalability depends on the modules you choose, the one I chose is best in terms of modularity, all I have to do is add a panel and fix a micro inverter to it and use the mobile app to sync with Envoy.

Originally Posted by honeybee

what is the power being generated on an average? In layman's terms how much excess at peak?

One can expect about 16 units (1 unit = 1kWh) on a good sunny day. I have seen it reaching closer to 18 units and I expect good production during summer and winter. For my home, about 9 units are sufficient per day, so at the moment about 7 units are excess. There is no peak excess counted but net metering arrangement calculates consumption - production delta.

Originally Posted by srini1785

1. What does the overall set up cost?.
2. What is the generation capacity in terms of KWhr?.

Its the first time I am seeing an actual on-grid installation. I have always assumed that solar power plants need a battery bank and are off-grid. So an eye opener for me.

On subsidies, I think that none of the distribution companies would subsidize capital expenditure. They will only offer a power purchase agreement. Its the same whether its solar or bagasse based co-gen plant or any power plant that sells its power to state distribution companies.

It cost me around 2.8L, from various quotes I have seen its about 70k per kWh capacity.
On average 4kWh is expected to produce about 16 units(kWh) per day.

If Govt websites are anything to go by :
Up to 3kW – 40%,
4kW to 10kW – 20% &
More than 10kW – 0%

There are few forum members in North India who managed to get the subsidy in 2020 itself. If my DISCOM had offered subsidy cost would have come down by approx 1L upfront.

Originally Posted by Chillout

could give the breakup cost for panel, inverters, wiring etc, it would be useful. Also looks like you still haven't figured the perfect grid profile

Per Panel: ~10k/400Wh (spec explained earlier)
Per Inverter: ~15k
Wiring and electrical accessories: ~30k
Manpower costs not shown.

Grid profiles: They are enphase specific thing, I believe I have narrowed down to ideal one but I will keep a tab.

[Thilak29]

Originally Posted by maddy42

So yours is a on grid system?
Will the constant power cuts reduce your revenue?
Also whats the cost of your setup?

Maddy

Cost is mentioned above in my response, kindly refer. Yes Grid-connected, Power cuts reduce production and in turn revenue. Selling power is not the only means of making it worth it, if you are able to produce enough to match your needs its good enough.

When electricity is used for the majority of home needs (including Dishwashing!) it makes sense to go Solar, power tariff only goes upwards and with usage, you end up falling into a higher tariff band. If EVs too become reality in India Solar makes even more sense!

[condor]

Thilak, thanks for sharing this.

What angle should the panels be at ?