[jkdas]

Originally Posted by Prowler

You are absolutely right. As you put it so succinctly, if you install enough surface and you have large enough open area with no impediment - you can still get a decent output. Using my experimental solar cell matrix figures, for the same required output we may need 40 % more solar cells.

As per this site (http://www.targetwoman.com/articles/...-lighting.html) it costs about US $ 2.45 per W. For a modest 1000 W we would need to spend about US $ 2450 or around Rs.130,000/- for solar cells alone.

That page also talks about Hybrid Solar systems - but the catch is all these are available only in the US.

IIRC, Hykon 1.5KW ones with battery etc comes to 1lac ( after subsidy!). Will try to get paper clipping.

[Thad E Ginathom]

OK, so I'll put the solar-turbine fantasy to one side, with solar-cell generation still marked pending --- and thank you all for the input on this. I think it is going to be pending long enough for me to spend 16 to 20 thou now on traditional inverter.

it looks as if the next step, just powering my little den, would be this SuKam Brainy, with 3 80w panels and 150amp-hour battery at 50,000. 11.00am to 6.00pm of my computing day would get free electricity, though.

i think that would "save" me about Rs.5 a day

[Prowler]

Originally Posted by Thad E Ginathom

it looks as if the next step, just powering my little den, would be this SuKam Brainy, with 3 80w panels and 150amp-hour battery at 50,000. 11.00am to 6.00pm of my computing day would get free electricity, though.

Thanks for the link. They seem to offer the lowest price for UPS. A Sukam 850 VA with a 100 AH battery for just about Rs.13200/- seems like a steal. Considering the situation in TN, I would have to order one now. Thanks again Thad.

[Arch-Angel]

Originally Posted by Prowler

A Sukam 850 VA with a 100 AH battery for just about Rs.13200/- seems like a steal. Considering the situation in TN, I would have to order one now.

Please write an ownership review . That aside, for a serious purchase, i would suggest getting either exide or amaron. They are tried and tested brands. The best combo would be an APC inverter with an exide tubular battery with regards to my experience with the products.

[Thad E Ginathom]

Please also tell us if you able to order from this Bangalore dealer for Chennai delivery!

[diyguy]

Originally Posted by Thad E Ginathom

Please also tell us if you able to order from this Bangalore dealer for Chennai delivery!

I have just enquired from my dealer and got a quote for Rs 6500 for 850va APC and Rs 13500 for Exide tubular. PM me if you want the number and I think we can get a few 100s off if more than one of you want it. I had got the same setup last year for Rs 18000 all inclusive but still feel the new rate is competitive.

[Prowler]

Originally Posted by Arch-Angel

Please write an ownership review . That aside, for a serious purchase, i would suggest getting either exide or amaron. They are tried and tested brands. The best combo would be an APC inverter with an exide tubular battery with regards to my experience with the products.

I agree. But I have been using a 3 KVA UPS for our office from a local manufacturer. Touch wood - I haven't faced any major problem in the last 6 years. I am on the second set of batteries now.

I am only looking at the offer price from Thad's link. I have made inquiries in Madras and no one can come down to less than 18k for 850 VA inverter/100 AH battery.

I have just enquired from my dealer and got a quote for Rs 6500 for 850va APC and Rs 13500 for Exide tubular. PM me if you want the number and I think we can get a few 100s off if more than one of you want it. I had got the same setup last year for Rs 18000 all inclusive but still feel the new rate is competitive.

I would first check with the Bangalore dealer. Give me a few days time.

[Prowler]

I checked with the Bangalore office and they won't ship to Madras. So I contacted local office here and they can offer the same (without the plastic trolley) for Rs.13.5 k

They will revise the price this week.

[Prowler]

They finally delivered the Sukam Inverter and the battery for Rs.13500/-
The inverter is silent enough except for the fan. Only issue is I haven't bothered to reroute the kitchen appliances to a different circuit which means someone has to be cautious not to use any of them when in inverter mode. I have kept the mains/inverter switch ( I have separately wired it with a 15 A switch) on in mains mode for now.

[katpasin]

I am considering inverter vs generator for my home. Summer is almost here and at least 2 hrs power cuts will be the norm.

Generator: My building has provision for 600watts power backup to every flat, but now this will be charged at Rs15/unit.

This made me consider my options, would a inverter turn out cheaper? how many years would it take to break-even from what i am going to pay for my building's backup?

[k2max6]

Originally Posted by katpasin

I am considering inverter vs generator for my home. Summer is almost here and at least 2 hrs power cuts will be the norm.

Generator: My building has provision for 600watts power backup to every flat, but now this will be charged at Rs15/unit.

This made me consider my options, would a inverter turn out cheaper? how many years would it take to break-even from what i am going to pay for my building's backup?

Is the 600W backup sufficient for you?
If yes. I would suggest continue using it rather then buying an inverter.

An inverter with similar backup would cost your around 25k with 2 batteries.

Add to it the cost of electricity consumption and change of batteries every 3 years approx.

I can't comment on the exact electricity consumption by the inverter but still you would be better off with the building's power backup.

Moreover in case of a long cut you don't need to be worried of the time, which you will have to in case of an inverter.

Since 2 hours is the norm you would hardly save anything if at all.


My 2 cents.

[katpasin]

Originally Posted by k2max6

Is the 600W backup sufficient for you?
If yes. I would suggest continue using it rather then buying an inverter.

An inverter with similar backup would cost your around 25k with 2 batteries.

Add to it the cost of electricity consumption and change of batteries every 3 years approx.

I can't comment on the exact electricity consumption by the inverter but still you would be better off with the building's power backup.

Moreover in case of a long cut you don't need to be worried of the time, which you will have to in case of an inverter.

Since 2 hours is the norm you would hardly save anything if at all.


My 2 cents.

Hmm.... Thanks
Makes sense... I was worried on the initial setup cost of an inverter and regular maintenance.

I dont put ACs and geysers on the backup.
Have 5 Fans, 6 CFL on the backup, however do not use all of them together, also have my desktop, LCD and laptops connected. In short, takes care of my essentials

[hellmet]

Guys, I'm sorry I haven't read the 30+ pages of this thread, so my questions might have already been answered. Thank you for patiently re-answering some questions. The reason I ask you and not a salesman is because I can trust your inputs and get much more real-life data than from a salesman who most probably has no experience running a power backup himself.

The issue here is that my city (Hyderabad) will soon start 6 hour power cuts (4hour cuts last year. Already 2 hr cuts have begun) so I really do not like the idea of sitting without power in the house in this day and age for 1/4 of my day.

This is a list of appliances I'd like to run at maximum. Not all appliances and devices may be in use at the same time, but just taking them into consideration.

4CFL bulbs X 22 W = 88W (bedrooms+living)
3CFL bulbs X 11W = 33W (bath)
2Tubes X 40W = 80W (kitchen+dining)
4Fans X 60W (they're rated 100W but who runs them at full speed?) = 240W
Two plug points for various devices (laptops/cellphones chargers) X 50W = 100W
1 Mixer-Grinder = 500W (had no idea it was such a power hungry item)
Refrigerator rated as 180W defrost, 160 W input, 0.7A. No idea what this means = 180W
1CRT TV X 83W = 83W
DTH STB = 30W
1 Wireless Router + 1 Modem = ??W (counting another 50W) = 50W

Total: 1,384 W

Now the refrigerator is not a must, but I don't really know the implications of having 6 hour power cuts on an appliance like this. I hope it doesn't die trying to cool itself after an elongated cut.

I'm looking to run this configuration entirely on battery+inverter technology with an option for it to recharge via Mains, Genset, or other intermittent supplies such as Solar or Wind, in that order of preference. My goal is to be able to survive grid break downs (of 2-3 days) such as those seen in North India, because with such acute power shortages in AP, it is bound to happen sooner or later.

I'm guessing a Petrol Genset would be a good idea since Kerosene is not freely available and gas stations would run out of diesel first due to heavy genset and public transport demand. I also want one that is as silent as possible to keep ourselves sane in the house, so I can only think of petrol.

Remember that this genset would only run after the inverter starts to run out of juice and not everytime we have a power cut. So, both devices must be able to handle the load mentioned above individually. Can gensets start on their own detecting a load?

What do you guys suggest we go for based on these (horribly long list of) requirements?

[Thad E Ginathom]

Only a small difference, but you can really cut down on the lighting.

You can light a work or reading space with a 5 or 8 watt cfl desk lamp, and LED could be even less. If you have a couple of those in a room, you will also have background lighting, albeit dim. There is no need for 40w tubes: just light the necessary areas. You might even find this approach to lighting to be refreshingly restful! We can get by, in our hall, with wife and I at our computersat opposite ends of the room, on a total of 10-15 watts for lighting during a power cut.

If you must have full light, or family means there are too many individual places to economically light, T5 tubes are, I think, only 28w.

If maximising the battery-backup duration is the priority, then consider that, when not doing reading, sewing, etc, all that is necessary is to be able to see one's way around the room! Even with a genset, this will save you fuel.

[joybhowmik]

Originally Posted by hellmet

4CFL bulbs X 22 W = 88W (bedrooms+living)
3CFL bulbs X 11W = 33W (bath)
2Tubes X 40W = 80W (kitchen+dining)
4Fans X 60W (they're rated 100W but who runs them at full speed?) = 240W
Two plug points for various devices (laptops/cellphones chargers) X 50W = 100W
1 Mixer-Grinder = 500W (had no idea it was such a power hungry item)
Refrigerator rated as 180W defrost, 160 W input, 0.7A. No idea what this means = 180W
1CRT TV X 83W = 83W
DTH STB = 30W
1 Wireless Router + 1 Modem = ??W (counting another 50W) = 50W

Total: 1,384 W

I am assuming a scenario of Power Factor = 0.5 - this is not unreasonable considering the range of devices in your list.
Having said that your VA requirement = 1384/0.5 = 2768.

This implies the typical home inverters varying from 675 VA ~ 1500 VA will not be able to bear the load in the instance that all these devices are switched on at the time of power failure. This would likely trip the MCB protecting the UPS box instead of affecting the box itself.

While you can go in for buying a larger capacity inverter and more batteries, it is definitely easier to re-consider if you really need all the devices to have full power backup at all times.

It may be easier and cheaper to do the following:
Start by making a list of devices satisfying the following criteria:
List 1: Device needs to be working 24X7
List 2: Device is likely to be used only intermittently- maybe half-hour to an hour at most.
List 3: Device is likely to be used only during the night.

A) After enlisting , work out the base VA requirement that your UPS should support (viz List 1).
B) Next find out the maximum VA requirement of List 2 and List 3, and add that max. VA requirement to the base VA requirement
Add A to B , and - that's the capacity of the inverter you 'should' buy.

Next , you should also run a separate power line from UPS output to the devices in List 1, and make a provision to power on devices in Lists 2 & 3 (e.g. an extension board connected to the UPS output).

This will ensure that your UPS+battery is never bearing an unreasonable load.