Solar powered AC air conditioning, a bummer or a challenge?

[Shockah]

Yes I have proven a viable by using it for the last 6 years.

Show me a $10 battery that will sustain 216wh and I will buy 100 from you...

[Shockah]

Hello? Abe? You got info on that $10 battery yet?

Oh well,,, it appears your modem was running on one of them...

Yawn!... I'm going to sleep, with a grin ...

[K7ABE]

Show me a $10 battery that will sustain 216wh and I will buy 100 from you...

Yes, I agree I would buy them too. The most I have been able to get at one time is 14. Usually I only get 1, 2, 3, or 4 of them at a time. But for getting started it is still much cheaper than ruening a new set of $300 batteries. My first set was $50 and included 10 $5 50A gelcells. And a broken arcosolar quad lam from the 1970s. They were cracked, look like rootbeer color, and still work fine. They went a long way encouraging me about the longevity of solar. The 300A bank I've used/tested for 6 years is made from four 75A gelcells and cost $40, $10 each. I would love to get 100 of them even if many of them were bad. If someone is looking for a turn key large setup I would recommend they talk to the Kimbell family in Miami Florida. But for anyone small-scale wanting to find out what solar can do I would recommend research and scrounging around. Much better than the $3 per watt for the on sale Harbor Freight set up. Many of my friends were discouraged with that 45W set up.
Abe

[K7ABE]

Hello? Abe? You got info on that $10 battery yet?

Oh well,,, it appears your modem was running on one of them...

Yawn!... I'm going to sleep, with a grin ...

Hey I am an old grey beard wearing glasses using a smartphone with neuropathy in my fingers. If I do it fast it has to do with American motorcycles antique muscle cars or eating.
Abe

[PhillyTitan]

You guys are cracking me up. I've completely lost focus.

[russ]

Results from PV Watts for Lufkin, TX for a 1 kW DC system - a derate factor of 0.82

RESULTS

3.47	83	8
4.37	96	9
4.84	114	11
5.53	125	12
5.45	123	12
5.77	123	12
5.97	131	13
5.91	130	13
5.63	122	12
5.33	123	12
4.01	91	9
3.66	89	9
5.00	1,350	$ 131

For Corvallis, OR - same system

RESULTS

2.22	53	4
3.39	73	5
3.32	79	5
5.32	121	8
5.23	121	8
5.67	124	9
6.60	148	10
6.20	140	10
6.01	134	9
3.34	78	5
1.97	44	3
1.63	37	3
4.24	1,151	$ 80

[Shockah]

Yes, I agree I would buy them too. The most I have been able to get at one time is 14. Usually I only get 1, 2, 3, or 4 of them at a time. But for getting started it is still much cheaper than ruening a new set of $300 batteries. My first set was $50 and included 10 $5 50A gelcells. And a broken arcosolar quad lam from the 1970s. They were cracked, look like rootbeer color, and still work fine. They went a long way encouraging me about the longevity of solar. The 300A bank I've used/tested for 6 years is made from four 75A gelcells and cost $40, $10 each. I would love to get 100 of them even if many of them were bad. If someone is looking for a turn key large setup I would recommend they talk to the Kimbell family in Miami Florida. But for anyone small-scale wanting to find out what solar can do I would recommend research and scrounging around. Much better than the $3 per watt for the on sale Harbor Freight set up. Many of my friends were discouraged with that 45W set up.
Abe

blah, blah, blah,,,

in your first post you said to crunch my 216wh daily usage numbers with a $10 battery and I'll get power at 1¢ per kwh... but there is no $10 battery that will sustain the usage,,,? the OP is looking for facts,,, not unicorns.

[PhillyTitan]

I know a great place to get a $10 AGM battery. It's the Batteries Plus in NeverNever Land, to the left past Bikini Bottom.
I'd love to get back on track here.

200 AH is meaningless without a voltage. So I can only assume you are talking about 6 volt 200 AH golf cart batteries wired in series to make 12 volts. 12 volts x 200 AH = 2400 watt hours. For an off-grid battery system you size the battery to give you 5 days run time. In reality this only gives you 2.5 days as you never want to discharge the batteries more than 50%. Put another way you only discharge your batteries 20% each day.

Battery cycle life and Depth of Discharge is directly related. The deeper you discharge them, the fewer cycles you will get out of them. Here is a chart to display:



Discharge 20% each day and you get about 5 years, 50%just over a year, 100% just a couple of months. In your case using a 12 volt 200 AH is 2400 watt hours and you want to drain 600 watts x 7 hours = 4200 watt hours. Not going to work.

So your air conditioner uses 600 watts and you want to run it 7 hours per day. 600 watts x 7 hours = 4200 watt hours. That means you need a minimum of 4200 watt hours x 5 days = 21,000 watt hours or 21 Kwh. To find the battery AH capacity is easy Amp Hours = Watt Hours / Battery Voltage. So you get:

1750 AH @ 12 volts
875 AH @ 24 volts
438 AH @ 48 volts

To determine cost a good 5 year battery will cost you $220/Kwh and weighs roughly 55 pounds per Kwh. So for a 21 Kwh battery will cost around 21 x $220 = $4620 and weigh in around 21 x 55 pounds = 1155 pounds.

I'm going to take this one step at a time. Two questions:

1: So our goal is to get the batteries to last 5 years, right? In order to get them to last 5 years, we'd have to run them down by only 20% of full capacity per day. Is this assuming that you ran them down 20% all 365 days a year?

2: I think I understand the table. Is "cycle" just another term for a single day's discharge and recharge?

[K7ABE]

I know a great place to get a $10 AGM battery. It's the Batteries Plus in NeverNever Land, to the left past Bikini Bottom.
I'd love to get back on track here.



I'm going to take this one step at a time. Two questions:

1: So our goal is to get the batteries to last 5 years, right? In order to get them to last 5 years, we'd have to run them down by only 20% of full capacity per day. Is this assuming that you ran them down 20% all 365 days a year?

2: I think I understand the table. Is "cycle" just another term for a single day's discharge and recharge?

The major factor in battery life will be how you treat them. Are they overcharged undercharged is electrolyte topped off do they run dry. If the batteries are well maintained then the brand name or type of battery will make a lot of difference In how deep your cycles can be without hurting the batteries and the longevity of the batteries. A little research will pay off here because our needs very And so do our investment abilities.

[billvon]

1: So our goal is to get the batteries to last 5 years, right? In order to get them to last 5 years, we'd have to run them down by only 20% of full capacity per day. Is this assuming that you ran them down 20% all 365 days a year?

There's no way you are going to get that accurate an assessment. In cold weather batteries last longer - but have a higher internal resistance. If you have a single string and an excellent charger, they will last longer than if you use a really basic charger to charge 3 strings. If you push them hard when they are cold but let them float when they are warm you'll see them last longer.

2: I think I understand the table. Is "cycle" just another term for a single day's discharge and recharge?

It's a charge and discharge, not necessarily one day.

[Sunking]

I'm going to take this one step at a time. Two questions:

1: So our goal is to get the batteries to last 5 years, right? In order to get them to last 5 years, we'd have to run them down by only 20% of full capacity per day. Is this assuming that you ran them down 20% all 365 days a year?

If you use a high quality battery like a Rolls 5000 series and treat them well you will get 5 to 7 years max out of them. Use a medium quality Trojan standard flooded lead acid battery 2 to 4 years. With that said regardless of the manufacture maximum battery life is obtained by shallow cycles of about 20%.

But here is the bottom line. Look at the battery warranty. It will tell you how long it will last with proper care and shallow cycles. For example a Trojan T-105 carries a 24/36 month meaning 2 years free replacement, and after 2 years prorated up to end of 3rd year. That tells you it is a 3 year battery. A Rolls 4000 Series battery caries a 24/60 which tells you it is a 5 year battery.

2: I think I understand the table. Is "cycle" just another term for a single day's discharge and recharge?

Yes that is basically what it means. Just keep in mind no battery will perform to the charts claims. They are not tested in real world application over time. They are preformed in a lab under ideal conditions in controlled enviroment on a accelerated schedule where they can get 4 or more cycles completed in a day.

[Shockah]

All in all,
it will cost you minimum 60¢ , 76¢, or even more per kwh,
if buying BRAND NEW AGM Battery(ies) that are large enough to cycle only 20%.

You could buy a cheaper/smaller battery and cycle it 50% or 80%...
but the life span is drastically cut.
I don't have a ¢ / kwh on that, because I've never gone that route.

One way to cut your ¢ / kwh is to employ FLA (Flooded Lead Acid) Batteries.
They are about half the price of AGM Batteries.
However, FLA requires maintenance of electrolyte levels.
There is no access to AGM's electrolyte.
Being that FLAs are maintainable, it is possible for them to have a longer life than AGM...
lowering your ¢/ kwh even more.

@ Hawaii's POCO rate of 37¢ to 49¢ per kwh,
it almost makes sen¢e to build an FLA off-grid system for a 5-7 year term...
if you have the time to maintain the batteries and a generator for extended cloudy periods.

[Sunking]

All in all,
it will cost you minimum 60¢ , 76¢, or even more per kwh,
if buying BRAND NEW AGM Battery(ies) that are large enough to cycle only 20%.

The price you are quoting is for FLA. AGm cost twice as much as FLA and last half as long. So in effect AGM is 400% higher than your quote.

You could buy a cheaper/smaller battery and cycle it 50% or 80%...
but the life span is drastically cut.
I don't have a ¢ / kwh on that, because I've never gone that route.

If you ran the numbers you would find cheap batteries cost are higher. A cheap Wally World Box Store battery will cost you roughly $100/Kwh of storage and you are looking at 1 to 2 years. A good 5 to 7 year battery cost $220/Kwh. When you run the numbers a cheap battery cost $100 / 146 Kwh = $.68 Kwh, vs $220 / 511 = $.43 Kwh

@ Hawaii's POCO rate of 37¢ to 49¢ per kwh,
it almost makes sen¢e to build an FLA off-grid system for a 5-7 year term...
if you have the time to maintain the batteries and a generator for extended cloudy periods.

Not so sure that is true. On th eIslands you cannot buy batteries as cheap as you can on the mainland. For example a Rolls 6CS25PS cost $1220 in the lower 48 drop shipped. Is suspect it is considerable higher in Hawaii like everything else cost there. With Hawaii heat and humidity you might be able to squeeze 5 years out of it if you are lucky. Heat kills batteries. At 90 degrees F will cut cycle life 50%.

[PhillyTitan]

All in all,
it will cost you minimum 60¢ , 76¢, or even more per kwh,
if buying BRAND NEW AGM Battery(ies) that are large enough to cycle only 20%.

You could buy a cheaper/smaller battery and cycle it 50% or 80%...
but the life span is drastically cut.
I don't have a ¢ / kwh on that, because I've never gone that route.

One way to cut your ¢ / kwh is to employ FLA (Flooded Lead Acid) Batteries.
They are about half the price of AGM Batteries.
However, FLA requires maintenance of electrolyte levels.
There is no access to AGM's electrolyte.
Being that FLAs are maintainable, it is possible for them to have a longer life than AGM...
lowering your ¢/ kwh even more.

@ Hawaii's POCO rate of 37¢ to 49¢ per kwh,
it almost makes sen¢e to build an FLA off-grid system for a 5-7 year term...
if you have the time to maintain the batteries and a generator for extended cloudy periods.

Ok, so here's a question I'm sure you guys have heard, if you'd be so kind.
Cost and personal feelings aside, rank the types of batteries from best to worst.

[Sunking]

Ok, so here's a question I'm sure you guys have heard, if you'd be so kind.
Cost and personal feelings aside, rank the types of batteries from best to worst.

I can only assume you mean FLA for cycle applications like RE. Batteries are made to do different things. So for a FLA RE applications.

1. Rolls 5000 Series, followed by the 4500 and 4000 series. The 5000 series will get you 5 to 7 years service if kept cool, shallow cycled, and TLC. 4500 series a 4 to 5 year, and 4000 around 3 to 4 years
2. Trojan Industrial Line is a solid 4 to 5 year battery at moderate price levels.
3. Trojan RE series a good 3 to 4 year battery
4. Trojan standard deep cycle 2 to 3 year battery
Anything from Wally World or a box store a 1 to 2 year battery

There are some other very good manufactures out there like Deka, C&D, Enersys but those are high end utility models for special purposes.