[PGA]

Originally Posted by Holyghost

However, as I said earlier, if your inverter has 2 MPPT trackers, the panels will be wired as 2 seperate banks. In this case you can divert just 1 bank (8 panels) of 2.5KW of power to your secondary inverter. You will need only a MPPT inverter with 2.5 - 3KW capacity which will generally support 24V battery banks. A good 2.5KW Offline Solar Inverter which can support surge currents upto 2x the rated power can easily run a 1.5T AC as long as you have proper sunlight.

Thanks a lot for a very comprehensive advise, it has been most helpful in clearing a lot of doubts in my head and it will certainly assist in working out a suitable configuration to meet my requirements.

BTW the panels have been wired in series and as one bank, MPPT tracker also has only one input so I assume its a single 5 KW inverter, accompanying brochure speaks nothing on any of the the issues you brought out.

Warm regards

[Holyghost]

Originally Posted by PGA

BTW the panels have been wired in series and as one bank, MPPT tracker also has only one input so I assume its a single 5 KW inverter, accompanying brochure speaks nothing on any of the the issues you brought out.

Warm regards

Could you please specify the Manufacturer of your Inverter? You specified only the Model name MPPT VFD800-10A which I couldn't find the right one in google.
If you do not find a Neutral Line for the inverter output, Then probably it may not support unbalanced load across phases.
Also a Single Phase 5KW Offline inverter with 800V DC input will be a difficult find.

[ecenandu]

Originally Posted by ecenandu

So, here are the stats after 13 months.

A proper bill after 13 months, no more confusion on import and export of electricity.

Zones

Normal : 6 AM to 6 PM.
Peak : 6 PM to 10 PM.
Off Peak : 10 PM to 6 AM.

[ecenandu]

An interesting video.

https://www.youtube.com/watch?v=YYLzss58CLs

[PGA]

Originally Posted by ecenandu

An interesting video.

https://www.Youtube.com/watch?v=YYLzss58CLs

Time is now ripe for a quantum leap in technology of batteries or any other type of storage device. I am not aware what is radically different from technological point of view with batteries being made by Tesla. Can they be as viable for general purpose use as a lead acid battery today. Otherwise solar grid may have to be networked across the globe to overcome the problem of duck curve.

[Fillmore]

Does anyone have a refrigerator that runs totally off a Solar grid setup ?
If so could you kindly share the make and model number ?

I am looking for a small refrigerator.
I see that this model by Samsung is certified for a Solar setup, but not much power consumption details are listed.

https://www.samsung.com/in/refrigera...oor-rr20m1y2x/

Samsung support when asked is giving half baked answers.

[BaCkSeAtDrIVeR]

Here is what my parents have. It is from TATA Solar, and cost about ₹ 2 lakh and was commissioned on 07 February, 2018. Payments were made in December 2017. I'm posting this exactly 10 months later, on 07 December 2018.


This is an off - grid unit, and is manually controlled using the red knob on this. This thing (below pic) is inside the house. Don't ask why they chose the manual rather than auto control.


The ACDB distribution box. (Alternating Current Distribution Box)





From output of the solar inverter and the mains power meter, lines come here. The red turning knob decides what goes into the ELCB aka main switch, from here power is distributed to various appliances. And, oh, you decide where the knob should be. So, power is in your hands.



Directions of the panels:-




Solar panels:-




Mounted on roofing sheets aka "tress" work.


If one looks well, the panels could have been moved a bit West, left in the pic. Now, they are too much East of the roofing sheet, where nearby trees cast shade till 9 am. Note the panels are note easily accessible, a poor decision by customer.



On t_he terrace, covered by the roofing sheets, we have this:-


8 batteries, and the inverter. Cost included the stand.




The battery:-


The inverter:-




Rear view of the inverter:-




The connected load, as per KSEB bills, is 4 kw. The solar unit is only 2 kw. (Or kva, whatever). Don't know about formalities, if any, including subsidies. The 2 lakh figure is taken from the bank statement.



Bills used to be in ₹ 5k range, are now in 2.5 k range, mostly because the tariff "telescoping" benefit is now available. Earlier, entire consumption was billed at higher rates. Total average consumption used to be 12 odd units. Simultaneous to installation of solar, i compelled installation of ELCB and MCBs. The cast iron main switch was junked. Now, average consumption is approx 10.5 units per day (total of solar plus mains).



Since solar <> mains changeover is manual, there is severe inefficiency. Lesson learnt is that connected solar power should be at least equal to installed load. (4 kva, in this case)

All appliances except a heater and washing machine are through solar.


Will post more pics later, if needed.

[rrsteer]

I have got a 2kw Tata BP solar system installed at my house.
For the last 2 months - Oct & Nov, I got charged for just 65% of our household electricity consumption. With winters now, I except to be charged about 50% of the actual electricity consumption in the next bill.
For the whole year the solar panel generates about 21% of our household requirement. I wish I could increase that figure but with 8 panels and a terrace garden - I have no space left.

[maddy42]

Originally Posted by BaCkSeAtDrIVeR

Here is what my parents have. It is from TATA Solar, and cost about ₹ 2 lakh and was commissioned on 07 February, 2018. Payments were made in December 2017. I'm posting this exactly 10 months later, on 07 December 2018.


This is an off - grid unit, and is manually controlled using the red knob on this. This thing (below pic) is inside the house. Don't ask why they chose the manual rather than auto control.



Mounted on roofing sheets aka "tress" work.


If one looks well, the panels could have been moved a bit West, left in the pic. Now, they are too much East of the roofing sheet, where nearby trees cast shade till 9 am. Note the panels are note easily accessible, a poor decision by customer.



On t_he terrace, covered by the roofing sheets, we have this:-


8 batteries, and the inverter. Cost included the stand.


The connected load, as per KSEB bills, is 4 kw. The solar unit is only 2 kw. (Or kva, whatever). Don't know about formalities, if any, including subsidies. The 2 lakh figure is taken from the bank statement.



Bills used to be in ₹ 5k range, are now in 2.5 k range, mostly because the tariff "telescoping" benefit is now available. Earlier, entire consumption was billed at higher rates. Total average consumption used to be 12 odd units. Simultaneous to installation of solar, i compelled installation of ELCB and MCBs. The cast iron main switch was junked. Now, average consumption is approx 10.5 units per day (total of solar plus mains).



Since solar <> mains changeover is manual, there is severe inefficiency. Lesson learnt is that connected solar power should be at least equal to installed load. (4 kva, in this case)

All appliances except a heater and washing machine are through solar.


Will post more pics later, if needed.

Thank you so much for the info.

Couple of queries:
Is it possible to increase the Panels to 4KW setup? A friend of mine gets a 1500 credit each month from his setup in blr.
South seems to be the best direction for the panels, maybe a couple of panels could be moved to benefit during the shade?

Also try get a auto switch over box. You will be thankful ten years down the line when you have to do it manually.

How was the experience getting the approvals from the electricity board?

Originally Posted by rrsteer

I have got a 2kw Tata BP solar system installed at my house.
For the last 2 months - Oct & Nov, I got charged for just 65% of our household electricity consumption. With winters now, I except to be charged about 50% of the actual electricity consumption in the next bill.
For the whole year the solar panel generates about 21% of our household requirement. I wish I could increase that figure but with 8 panels and a terrace garden - I have no space left.

Thank you for the info. Hopefully in a couple of years the panel ratings would be better on space for an upgrade. I think this is a good start and you have a point of reference on your usage and based on your tracking, you will note a steady increase in consumption as more things gets connected.


Maddy

[BaCkSeAtDrIVeR]

Originally Posted by maddy42

Couple of queries:
Is it posısible to increase the Panels to 4KW setup? A friend of mine gets a 1500 credit each month from his setup in blr.

I doubt about the panels. The inverter is 2 kva. So, technically not feasible - unless the inverter is replaced. Also, my parents handled this, while I was rooting for an expansion of the house before doing this. There is no way me or my siblings can stay together with our kids on holidays or on occasions now.

South seems to be the best direction for the panels, maybe a couple of panels could be moved to benefit during the shade?

Yes, but as mentioned, the set up was spec'ed by my parents. I suspect they simply named a budget, and the sales guys decided the rest.

Also try get a auto switch over box. You will be thankful ten years down the line when you have to do it manually.

What will be the cost? Also, how will this manage things on cloudy days?

They don't want to go without power during night times, so, if the sky is cloudy on 2nd day, we use mains power full time during day time and change to solar during late night - battery mode, that is.

Longest continuous time on on solar so far was when we used 32 units in approximate 52 hours.

Once the batteries are exhausted, the light on ACDB Meter goes off and it takes up to 28 hours of bright light (sometimes, this happens over 3 days) for the led light to come on again.

How was the experience getting the approvals from the electricity board?

I don't know what approvals were taken. As stated, my parents handled this, and I doubt they went to the KSEB Office. Not sure if TATA Solar people did the paper work.

My guess is that no paper work was involved since this an off-grid unit functioning like a battery powered inverter.

you will note a steady increase in consumption as more things gets connected.

Hmmm. You are right. The house is already 30+ years old. No a/c though.

They at least ought to have done a re-wiring. I had to insist on changing the mains switch to ELCB + MCB setup. Some switches are having loose contacts. Earthing too, is not perfect. These will be fixed.

If you note the reading my first pic of the ACDB, the consumption from solar works out to approx little more than 4.5 units per day. On 6 December, the KSEB reading was taken, and average consumption from mains is tad more than 6 units per day. A week back, had (personally) checked the batteries, and the 8 batteries took in 10 litres. When back up was going down, the service technicians were called in November, and I'm told they insisted that batteries are ok. Sigh.

I think I can expect 8 units usage from solar power per day from a 2 kva set up.

So, the average consumption from mains ought to be below 3 units per day.

Can anybody please explain the middle position (main) of the knob on the ACDB? I have to switch off the ELCB or MCB, and this is not really "off". Is it that way?

One advantage I see from using off grid solar power is that power is better while on solar. Voltage is always 230 V. On KSEB installed meter, the voltage shown is almost always around 220, and often in 21x range. And guess this is what we get if solar set up is on-grid. Also, with on-grid set up, if mains power fails, we too go without power.

[BaCkSeAtDrIVeR]

Originally Posted by Fillmore

Does anyone have a refrigerator that runs totally off a Solar grid setup ?
If so could you kindly share the make and model number ?

I am looking for a small refrigerator.
I see that this model by Samsung is certified for a Solar setup, but not much power consumption details are listed.

https://www.samsung.com/in/refrigera...oor-rr20m1y2x/

Samsung support when asked is giving half baked answers.

Late reply, but I was puzzled by this post. Hence did not answer. But it strikes me that you might have been misled by the phrase "digital inverter technology". That has nothing to do with backup / power supply units. The "inverter motor" used in fridges, air conditioners, washing machines, etc is a technique (possibly proprietary) which controls and reduces power consumption of the motor depending on the load.



I am yet to come across a "solar" fridge. Just find a fridge which suits your needs and design a solar set up which suits the fridge.

[Fillmore]

Originally Posted by BaCkSeAtDrIVeR

Late reply, but I was puzzled by this post. Hence did not answer. But it strikes me that you might have been misled by the phrase "digital inverter technology". That has nothing to do with backup / power supply units. The "inverter motor" used in fridges, air conditioners, washing machines, etc is a technique (possibly proprietary) which controls and reduces power consumption of the motor depending on the load.



I am yet to come across a "solar" fridge. Just find a fridge which suits your needs and design a solar set up which suits the fridge.

Thanks for replying, I am aware of "Digital inverter technology". My criteria was to find a medium sized fridge that consumes very less power. (whether the fridge was based on inverter technology or not was not my criteria, though if it consumes low power it would most likely be based on the new gen inverter technology motors)

I just have a 850VA off grid Solar setup and this refrigerator runs off it without any problems. This is for a weekend remote home types so the house has just around 3 LED Tubelights , 2 fans, 3 LED bulbs and this refrigerator.

So far it's been fine. Unless it is a gloomy day with no sunlight , this setup runs off the solar setup.

Posting 2 pics

[Rocky_Balboa]

Hi Folks,

Need Your advice on my requirement, please bear the long post.

Situation:
a) Frequent power-cuts, erratic supply at my locality in Bangalore, sometimes as much as 4 hours on a sunny day and 8-10 hours on a rainy day
b) My current Inverter with 150AH battery lasts for 4 hours with one fan, three lights and a television/ STB and wifi/ laptop on charge
c) Over the years of installation, battery being 2-3 yrs old and inverter being 7-8 yrs old Sukam Falcon, i feel the backup time is decreasing and battery levels get depleted faster
d) I consume about 250 units a month, while this increases during winter season by another 100 or so units
e) The consumption may increase by another 50 units or so going forward


Requirement:
a) Need a reliable option that can charge my inverter battery harvesting solar power; and hopefully improve backup time
b) And if there is excess, route to grid - not a must though


Could You please suggest if I need an off-grid or on-grid setup for my above requirement.


Additional details:
a) Solarify (got off the web) quotes 2.3L for an 2kW on-grid system, that can deliver about 300 units a month
b) Green Power (TATA BP Solar franchise) quotes 2.9L for a 3kW on-grid system, and claim 250 units a month

Both the companies claim there will be additional charges - MMS structure, cabling etc
Green Power also claims Approval from BESCOM, charges etc are not included in price; while Solarify claims to include them in their price.

I am not even sure how to read the above quotes and if I indeed need a solar system!
Please help.

Thanks for reading the long post.

[PGA]

Originally Posted by Rocky_Balboa

Hi Folks,

Need Your advice on my requirement, please bear the long post.

Situation:
a) Frequent power-cuts, erratic supply at my locality in Bangalore, sometimes as much as 4 hours on a sunny day and 8-10 hours on a rainy day
b) My current Inverter with 150AH battery lasts for 4 hours with one fan, three lights and a television/ STB and wifi/ laptop on charge

Requirement:
a) Need a reliable option that can charge my inverter battery harvesting solar power; and hopefully improve backup time
b) And if there is excess, route to grid - not a must though


Could You please suggest if I need an off-grid or on-grid setup for my above requirement.

Broadly speaking your max charging current requirement is 14-15 amps for a 150 AH battery. So consider buying 12 V panels with a total charging capacity of 350 to 450W, rig up solar charge converter with a changeover from mains to solar and vice a versa and you are good to go.

The whole setup shouldn't cost you more than 12-13K and you can do it yourself in about 30 mins.

[Holyghost]

Originally Posted by Rocky_Balboa

a) Frequent power-cuts, erratic supply at my locality in Bangalore, sometimes as much as 4 hours on a sunny day and 8-10 hours on a rainy day

On-Grid systems do not work during power cuts and hence will not serve your purpose. There are Hybrid Grid-Tie inverters which has built in option for adding a battery, but the costs are too high.
Since you already have an Inverter and battery, just buy this or similar device from other manufacturers, add a few Solar Panels and you are good to go.