Solar - grid tied billing

[adder]

I edited my previous post about my slabs and units, see If you can permute exactly because I cant, of ever increasing power consumption of my house. Despite having solid data from 3 years.


Thats the thing you have to factor in power cuts, and the fact that you need batteries for inverters without which you cannot honestly do a cost analysis. For you PC/ventilator is the only critical item which needs back,since you stay in a flat which has a generator. For me I have a apc smart UPS for the gaming PC, apart from the main solar inverter, for me there are other creature comfort that is critical, I do not have a generator for back up like you, I have large batteries for that purpose which serves me 24hrs of pollution free backup.


Your 20 year analysis again isnt fair, you calculate on the basis that all the replacement will be only of lead acid battery which will be history in 10 years, for a enthusiast like me it will be history even before that.
. Night time load is a variable it varies from person to person, month by month, changes due to weather,season, new appliances, new family members, so cannot answer that, like I said its not black and white. You say 1000w load is that for the entire night or is for every hour of the night. If its the latter you will need a 32kw battery pack and people who have that kind of requirement should have atleast 10kw solar with lithium.


Let say I get a EV, there won't be any extra solar power to feed the grid when the EV will suck everything your solar makes, when its charging, in the US and other countries which have faster EV adaption, there is excess solar in day but there is a shortage in night because everyone on plugging in their EV for charging and because power companies pay you less for export and charge you more for import from the grid, they all are going for battery storage.
In the US, AU, EU everyone who has a grid tied setup are mostly adding batteries. Because the power companies there pay peanuts for your exported power.

In the offgrid world its all about using smart switches to make sure you run the heavy appliances when the sun shines. People with lithium battery don't care about it though.

 

[NotMyRealName]

I understand we need power backup in the real world, but this is to start with, a simple calculation. If you add every eventuality and possibility right in the beginning you'll never get anywhere, which is what was happening in that thread as well as here.

So don't look at it as your house or mine, just a standard house with a 1KW maximum load, not KWh. I meant 1KWh for the entire night hours. So we're battery sizing for 1KWh as well as calculating utilities bill for 1KWh per day(night) for the alternative no battery calculation.

Lets just look at lead acid for now, We can easily add a different battery config later.

Again, leave all the EV/Li, every factor you can think of aside. Ditto, weather, seasons.

If the calculations don't/won't work out for an ideal load situation, then no way is it going to when you factor in all the real variables.

 

[rdst_1]

I want a straightforward equation, not figures here and there which don't add up. Thanks for all your inputs mate.

If you won't be having an extra 2 battery inverter setup for power-cuts, then yes a simple grid-tied setup makes sense. But if one is going to have some form of backup, it will be necessary to look into batteries for cost analysis.
For example, I will have a smaller generator as well as a 4 battery inverter setup due to my unique predicament. I however, can survive without investing in Solar for the time being. Similarly, everyone has their unique predicaments.
Also, you have to keep one more thing in mind as well. Both batteries and solar panels are reducing in prices and will continue going down whereas tariffs are only rising and will continue to rise. Also, solar panels as well as Li-ion batteries don't become completely unusable after their marketed life terms. They only lose some of their efficiency(solar panels) and backup capacity (li-ion batteries).
Yes, of course, like any technology, the early adopters do have to pay a little higher price. However, there are some other benefits like independence from govt supply and clean electricity without voltage fluctuations that one can't discount as well.

 

[NotMyRealName]

Right, so the way i see it now is today batteries cost more than tariff. So why shouldn't i use the grid instead of getting batteries with a finite lifetime and recurring replacement cost. As and when batteries are cheaper than the grid tariff, i will buy and add batteries and go off-grid? Does that concept work then? I'm not debating the pros and cons of batteries vs grid or lead acid vs Li. I'm saying a lot of people are investing in battery based solar thinking it will save them money when they can just use their grid 24x7 and invest that money in better things. Till the technology becomes cost effective.

You guys are going on and on about battery backup. In a regular environment with infrequent and short power cuts, does anyone get an inverter+batteries for their entire house load? Fridge, washing machine, ACs, water pumps, the whole shebang? No, they get battery backup just for the essentials till the power returns. If you have such excessive power backup requirements then you're better going off grid anyway. I'm talking about people who have the option of using the grid at night but still get battery backup capacity FOR THE ENTIRE LOAD because their setup doesn't use the grid at night and they have to use batteries.

I'll continue this tomorrow or later, I'll do the calculations myself and let the facts speak for themselves.

 

[adder]

So don't look at it as your house or mine, just a standard house with a 1KW maximum load, not KWh. I meant 1KWh for the entire night hours. So we're battery sizing for 1KWh as well as calculating utilities bill for 1KWh per day(night) for the alternative no battery calculation.

So assuming your total night time i.e after sunset load is 1000kwh till the next sunrise power generation, then will need a 12v 170ah battery DoD 50%, which cost? but a 200ah battery cost 18k for exide solar battery.
if Rs9per unit incl gst, thats Rs 3240/ year after 7 years Rs 22680 well all know that tariff keeps increasing every year, atleast in karnataka its 0.25 to 0.50 paisa / unit year on year increase+gst. So even if the tariff is constant, you still save.

Right, so the way i see it now is today batteries cost more than tariff. So why shouldn't i use the grid instead of getting batteries with a finite lifetime and recurring replacement cost. As and when batteries are cheaper than the grid tariff, i will buy and add batteries and go off-grid? Does that concept work then? I'm not debating the pros and cons of batteries vs grid or lead acid vs Li. I'm saying a lot of people are investing in battery based solar thinking it will save them money when they can just use their grid 24x7 and invest that money in better things. Till the technology becomes cost effective.

So I invested 56k for batteries, its atleast gives you back up, and also returns money, it costs less then a Midrange 3 series graphics card, less then a iphone what ever is the current one.

You guys are going on and on about battery backup. In a regular environment with infrequent and short power cuts, does anyone get an inverter+batteries for their entire house load? Fridge, washing machine, ACs, water pumps, the whole shebang? No, they get battery backup just for the essentials till the power returns. If you have such excessive power backup requirements then you're better going off grid anyway. I'm talking about people who have the option of using the grid at night but still get battery backup capacity FOR THE ENTIRE LOAD because their setup doesn't use the grid at night and they have to use batteries.

I'll continue this tomorrow or later, I'll do the calculations myself and let the facts speak for themselves.

Mine is a regular enivornment, power cuts are there not due to shortage of power, its due to piss poor grid maintence. If it rains or windy they cut the power and if they dont you hear boom sound and the power fails, when it does come back its usualy just 1 phase, with low voltage on the other phase, if god forbid it rains for the entire night. The power/fault is fixed only the next morning. I had instances of high voltage 350v plus for weeks and it happens only after 11pm till early morning, complaints went to deaf years. Only after relentless complaints to higher ups did it get solved, the damage was already done to the devices in the house and to the my mental state. I had made up my mind to go off their grid.

Since 2 days, my RCBO keeps tripping because the SPD is detecting a surge and this happened after I heard a boom sound from the grid, when the power resumed street lights where flickering, with half the street who where in the effected phase out of power.

They also cut power for tree branch cutting drives. So yes getting quality power is crucial.

So yes back up matters, my cousin has genset back up that powers their entirehouse including the fancy elevator but then again they drive a RR phantom in India. So to each is own.

 

[JMP]

@adder - Are you planning to go completely off grid now ? As in will you disconnect your BESCOM power line ?
I ask this because the hybrid Flin Fusion inverter you and @rdst_1 have mentioned is not on BESCOM empaneled list, so you won't get approval to have any kind of grid tie from BESCOM.

From what I have researched, Power Purchase Agreements (PPAs) are valid for 25 years from the date of signing, at present BESCOM is offering net metering - meaning the bill you receive is a simple difference between units you have produced and units you have consumed + fixed charges, irrespective of their actual costs (priced according to the slab of course).

Also, hybrid inverters are a lot more expensive per kw than gird tie inverters. So, with net metering in mind doesn't it make sense to get a large on grid solar setup (10 kW) under a PPA and have an emergency backup (2-4 kW) using a conventional inverter (like Luminious Cruize) with Lithium / Lead acid batteries. In this scenario the batteries won't be drained every night which increases their life span and you'll be able to use the grid both during day and night to charge EVs and heavy appliances without worrying about any hike in charges for the next 25 years.

 

[rdst_1]

@adder - Are you planning to go completely off grid now ? As in will you disconnect your BESCOM power line ?
I ask this because the hybrid Flin Fusion inverter you and @rdst_1 have mentioned is not on BESCOM empaneled list, so you won't get approval to have any kind of grid tie from BESCOM.

From what I have researched, Power Purchase Agreements (PPAs) are valid for 25 years from the date of signing, at present BESCOM is offering net metering - meaning the bill you receive is a simple difference between units you have produced and units you have consumed + fixed charges, irrespective of their actual costs (priced according to the slab of course).

Also, hybrid inverters are a lot more expensive per kw than gird tie inverters. So, with net metering in mind doesn't it make sense to get a large on grid solar setup (10 kW) under a PPA and have an emergency backup (2-4 kW) using a conventional inverter (like Luminious Cruize) with Lithium / Lead acid batteries. In this scenario the batteries won't be drained every night which increases their life span and you'll be able to use the grid both during day and night to charge EVs and heavy appliances without worrying about any hike in charges for the next 25 years.

The Flin inverters can still be connected to the grid without any permissions required, when used in their normal Hybrid mode when one is not selling the electricity back to the electricity company.

The problem with going for grid-tie setup with net metering are multi-fold. First up, almost all subsidy schemes in India are a sham unless it is something like 80-85% subsidy. One is forced to get work done from govt appointed vendors and choose from their approved hardware which is almost always priced grossly higher than it's current market price, if one were to buy it themselves.

I once met a guy who is used to setting up these huge solar power plants and projects and has even worked closely with our govt when formulating policies for solar power systems and be told me this is all a sham and not to get sucked into this due to subsidy. He also told me the real truth of PPAs and how there are clauses which allow the govt/purchasing companies to slash prices at their will. This is also happening all over the world and is not just an Indian phenomena, where grid operating companies and traditional power generators are finding it difficult to compete with solar and hence cutting down the prices they pay for it.

Secondly, who has the time to deal with the mess that are government departments. If you can see from our statements in the other thread, both me and adder are fed up with the apathy of our respective electricity departments. I spent 2 lakhs a few years ago getting a personal borewell just because the govt water supply was and is still terrible in my area. For me, a solar setup doesn't make monetary sense because of having one of India's cheapest tariffs but I still might go for it in the near future as soon as I have the budget because of the freedom, independence and peace it provides me being independent of the mess that is dealing with government agencies.

Thirdly, getting the electricity company to allow/approve a net-metering setup is a huge chore in itself. It is easiest when the govt itself is promoting it in your area as the officers handling it are incentivised to help you, but after such drives are over, they will make you run around needlessly to get such a connection approved and can take upto an year of running around as documented by several people online. My relative is an XEN in my local electricity department and he himself told me to not to try for a net-metering setup as the paperwork is huge and he knows how I get when dealing with incompetent government officials.

 

[adder]

@adder - Are you planning to go completely off grid now ? As in will you disconnect your BESCOM power line ?

Yes eventually, Even then there will be grid connection for the non stop rainy days, for the most part the mains will be off. Too truly go off grid you will need 20kw pack or more, with 10kw or more solar array.

I ask this because the hybrid Flin Fusion inverter you and @rdst_1 have mentioned is not on BESCOM empaneled list, so you won't get approval to have any kind of grid tie from BESCOM.

Yes the hybrid flin is not mre approved, as said in the other thread. Only flin infini hybrid design imported from another vendor with different name is mnre approved.

From what I have researched, Power Purchase Agreements (PPAs) are valid for 25 years from the date of signing, at present BESCOM is offering net metering - meaning the bill you receive is a simple difference between units you have produced and units you have consumed + fixed charges, irrespective of their actual costs (priced according to the slab of course).

rdst_1 perfectly summed up why we don't like grid tied.

Also, hybrid inverters are a lot more expensive per kw than gird tie inverters. So, with net metering in mind doesn't it make sense to get a large on grid solar setup (10 kW) under a PPA and have an emergency backup (2-4 kW) using a conventional inverter (like Luminious Cruize) with Lithium / Lead acid batteries. In this scenario the batteries won't be drained every night which increases their life span and you'll be able to use the grid both during day and night to charge EVs and heavy appliances without worrying about any hike in charges for the next 25 years.

I said in the earlier thread hybrid inverters cost as much as buying a separate grid tie inverter and off grid inverter. So it doesn't make sense. There are models which are hybrid which doesnt cost much but they will not get mnre approval.
The best of Lead acid batteries will fail whether you discharge them daily or whether you keep them in standby mode.
No lead acid battery will last more then 9 years and my maintenance was on the mark.
If you buy a cruze with 2 to 4kw chances are you will need the same amount of batteries as the flin, probably more.

Like I said for me there was 2 option go grid tie with a installer or go off grid inverter and batteries and because I did everything myself with zero help, it was way cheaper then a grid tie with subsidy.

 

[chetansha]

The basic reason for going solar is to go green. Putting huge battery banks defeats the very purpose of solar.

 

[adder]

The basic reason for going solar is to go green. Putting huge battery banks defeats the very purpose of solar.

lead acid battery is 90 to 99 percent percent recyclable depending on who is recyling
Australia supplies a large portion of their grid with tesla megapack. World over countries are looking at energy storage using green energy. Energy production will be challenge in future, with countries pledging to mostly add green power source, the problem with solar and wind is that they don't make power always and grid demand is more at night due to EV. Even a basic EV scooter pulls around 1kw and a car pulls around 3 to 7kw with the supplied/built in charger. With newer cars coming with 20kw onboard charger. When everyone plugs in their cars at night, the grid will collapse. A single car can suck as much energy as an entire street, in winter that's equal to a couple of streets.
The rates are high or will be high in night due to peak demand.

But if everyone has battery pack in their house. One could use a DC-DC to super charger their EV, without waiting for the power companies to upgrade their infrastructure.

 

[JMP]

Yes the hybrid flin is not mnre approved, as said in the other thread. Only flin infini hybrid design imported from another vender with different name is mnre approved.

Aren't you worried that BESCOM may levy huge fines on you / blame you, if something goes wrong / they come to know about it ?
(Even if its got absolutely nothing to do with your equipment they may simply make you a scapegoat.)

rdst_1 perfectly summed up why we don't like grid tied.

What's the advantage ? You still are maintaining a relationship with BESCOM and paying fixed charges every month for whatever capacity off grid system you build, because on those very rainy days the grid needs to support the same load. Also, AFAIK getting a PPA is a 1 time activity, costs about 2K if done on your own or 5-7K if done via agent.

I was looking into Flin inverters on Amazon, they appear to have 2 year warranty. Enphase IQs come with a 10/25 year warranty. May be that could be the reason for cost difference ?

 

[adder]

Aren't you worried that BESCOM may levy huge fines on you / blame you, if something goes wrong / they come to know about it ?
(Even if its got absolutely nothing to do with your equipment they may simply make you a scapegoat.)

Who said anything about selling to the grid. You cannot do that. Bescom has no issue if you use solar power to yourself, even if you own a hybrid inverter as long as you disable grid feed, bescom or any other escom will not have any issue. If you do accidently enable it, they the escoms will make money while you will be at loss. All grid tie inverters will not produce power when the grid fails, this is done to prevent electrocuting the line men. Its illegal to enable grid tie without approval.

What's the advantage ? You still are maintaining a relationship with BESCOM and paying fixed charges every month for whatever capacity off grid system you build, because on those very rainy days the grid needs to support the same load. Also, AFAIK getting a PPA is a 1 time activity, costs about 2K if done on your own or 5-7K if done via agent.

I was looking into Flin inverters on Amazon, they appear to have 2 year warranty. Enphase IQs come with a 10/25 year warranty. May be that could be the reason for cost difference ?

For now yes one has to pay the minimum I thinks it Rs95+gst for 1.5kw the sanctioned load. Bescom meter for single phase supports a load of 7kw. On occasions you can use the full power, of 7kw for a few min, the EB meter records average load for 30min, not the short term runs.

Getting a PPA is indeed a one time activity but contract for 25 years is a lot, they can change the tariff they pay you as they want. You cannot do it own your because they will do so only with bescom registered installers and with MNRE approved inverters, panels etc. I don't know about agents. But with such crappy suppy from bescom, where in one instance 2 phases touched because some idiot during the ganesha procession did not notice wires and it shorted resulting in 460v input, enough to screw up most of the appliances switched On and it would have definitely blown the grid tie inverter.

Regarding the IQ micro inverter its overpriced because micro inverters need to be IP67 and being under the panel, they have to withstand harsh temperatures and humidity and dust. So all the weather sealing increases prices. Flin energy gives 2 years warranty because the OEM of them which is voltronics taiwan also only give 2 years warranty
Schneider electric for eg only offers 3 year warranty and they cost 2x more. Victron energy again a reputed manufacturer of OFF grid inverters they give 5 year warranty again cost several times more then Voltronics OEM.

 

[rdst_1]

Aren't you worried that BESCOM may levy huge fines on you / blame you, if something goes wrong / they come to know about it ?
(Even if its got absolutely nothing to do with your equipment they may simply make you a scapegoat.)

What's the advantage ? You still are maintaining a relationship with BESCOM and paying fixed charges every month for whatever capacity off grid system you build, because on those very rainy days the grid needs to support the same load. Also, AFAIK getting a PPA is a 1 time activity, costs about 2K if done on your own or 5-7K if done via agent.

I was looking into Flin inverters on Amazon, they appear to have 2 year warranty. Enphase IQs come with a 10/25 year warranty. May be that could be the reason for cost difference ?

I think you are getting a little confused. A hybrid solar inverter without grid-tie is like a normal inverter but with solar option as well. So one installs it like any other inverter with which no electricity supply company has an issue. One doesn't need any kind of permissions for such a setup like you won't for a normal inverter.
As for the fixed charges you have mentioned, it is a very small charge to pay for the convenience of using the grid as per our usage. For example, some of the inverters even have a load sharing option where, when needed, the inverter uses all of the solar energy and pulls only the excess that is needed from the grid. So one ends up using as little energy from the grid as needed. Not all hybrid inverters have this option and some just completely switch to grid when energy requirements are higher than what the solar panels are producing.