Aquion Energy up and coming battery....opinions please

[SunEagle]

I was only using 50% DOD for the purpose of comparing the battery types, and did not imply they are to be used to that extent every day.

I did another cost comparison between the same batteries (ie FLA, LFP and Sodium Ion).

L16 FLA came up with a cost of $809 per Kwh (for the 20% useable you suggested) and is rated at a cycle life of 4000 (at 20% DOD)

LFP came up with a cost of $1417 per Kwh (for the 35% useable you suggested) and is rated at a cycle life of close to 7000 (at 35% DOD)

Sodium Ion came up with a cost of $962 per Kwh (for the 50% useable) and is rated for a cycle life of 6000 (at 50% DOD)

So if you factor in the cycle life for each, the overall cost, as I had mentioned previously, is still very close for all 3 battery technologies. I agree that the Aquion sodium ion batteries have issues with paying Mr. Peukert, and thus will not be suitable for many applications.

How are you calculating the $ / Kwh in bold type above? You may be correct but to me it looks like you are off by a few decimals.

[northerner]

How are you calculating the $ / Kwh in bold type above? You may be correct but to me it looks like you are off by a few decimals.

For the FLA I referenced a Trojan L16 rated at 370 ah @6v = 2.22 kwh total capacity x 20% useable = 0.444 kwh useable and is $359. Thus the price comparison for FLA is $359/0.444kwh = $809/ Kwh of useable storage.

For the LFP I referenced a Balqon 5.2kwh Battery Storage Pack and if comparing with an optimum of 35% useable is 5.2 kwh total capacity x 35% useable = 1.82 kwh useable and is $2580. Thus the price comparison for LFP is $2580/1.82 kwh = $1417/ Kwh of useable storage.

For the Sodium Ion I referenced an Aquion S20 which is 2.4 kwh and if comparing with an optimum of 50% useable is 2.4 kwh total capacity x 50 % useable = 1.2 kwh useable and is $1155. Thus the price comparison for Sodium Ion is $1155/1.2 kwh = $962.5/ Kwh of useable storage.

Hopefully no confusion using useable battery storage, but should give a better approximation of actual cost. Of course there will be many other factors which could affect overall cost!

[Sunking]

For the FLA I referenced a Trojan L16

Now go try a deep cycle battery, not a traction battery like a Trojan L16RE and factor in cycle life. Big difference. Or try the king of cycle life using any Rolls 5000 Series.

You cannot compare at initial upfront cost. Determine the $/Kwh of the entire life of a battery. When you go that route you get something between 30 to 70 cents per Kwh for FLA. LFP and Sodium will be higher. That is when you realize the mean ole greedy POCO is the best deal in town at 6 to 15 cents per Kwh for all you want round the clock.

I think you are also overlooking the charging sequence with solar. With solar you do not have the option of PSOC, it is opportunity charging of every day when there is sun, not when hit a Predetermined State of Charge like 20, or 50% SOC. Only time you will ever get to 50% DOD with FLA is when you have 3 cloudy days. At that point you need a generator or 3 days full sun to recover while you sit in the dark. That gig is best served by FLA. Having said that Trojan RE line-up is capable of PSOC with its Carbon/Lead technology just like Aquion without the headaches at a fraction of the cost.

[northerner]

Now go try a deep cycle battery, not a traction battery like a Trojan L16RE and factor in cycle life. Big difference. Or try the king of cycle life using any Rolls 5000 Series.

You cannot compare at initial upfront cost. Determine the $/Kwh of the entire life of a battery. When you go that route you get something between 30 to 70 cents per Kwh for FLA. LFP and Sodium will be higher. That is when you realize the mean ole greedy POCO is the best deal in town at 6 to 15 cents per Kwh for all you want round the clock.

I think you are also overlooking the charging sequence with solar. With solar you do not have the option of PSOC, and is opportunity charging of every day when there is sun. Only time you will ever get to 50% DOD is when you have 3 cloudy days. At that point you need a generator or 3 days full sun to recover while you sit in the dark. That gig is best served by FLA. Having said that Trojan RE line-up is capable of PSOC with its Carbon/Lead technology just like Aquion without the headaches at a fraction of the cost.

I was comparing costs and then factoring in the cycle life to come up with the final comparison.

As far as the charging sequence goes, you still only have about 20 or 30% useable with FLA and it's a constant battle getting the batteries mostly or fully charged every single day. I would be happier getting a decent sized battery, where I didn't have to worry about leaving it at a PSOC, and could just run the generator enough to make it through to the next day, if need be. Also, no wasted energy with absorptions and EQ's.

Also, I just checked the Rolls 5000 series and they post their cycle life at 5000 at 20%DOD, which is only 1000 cycles more than the Trojan's I just posted. The Trojans are actually more cost effective, as they are only about 60% of the cost.

[northerner]

Here is the costing comparing battery types and factoring in cycle life:

Trojan L16 is $809/4000 cycles = $0.202 per kwh @ 20% DOD

Balqon 5.2 kwh module is $1417/7000 cycles = $0.202 per kwh @ 35% DOD

Aquion S20 stack is $962.5/6000 cycles = $0.160 per kwh @ 50% DOD

Rolls 5000 series is $1314.5/5000 cycles =$0.263 per kwh @ 20% DOD

There is not much variation in estimated cost between all of these battery types.

[SunEagle]

Here is the costing comparing battery types and factoring in cycle life:

Trojan L16 is $809/4000 cycles = $0.202 per kwh @ 20% DOD

Balqon 5.2 kwh module is $1417/7000 cycles = $0.202 per kwh @ 35% DOD

Aquion S20 stack is $962.5/6000 cycles = $0.160 per kwh @ 50% DOD

Rolls 5000 series is $1314.5/5000 cycles =$0.263 per kwh @ 20% DOD

There is not much variation in estimated cost between all of these battery types.

Those $/kWh are closer to what I would calculate based on their lifespan. But to be fair when comparing costs of battery types I would try to size the systems with the same voltage and similar Ah rating. To me that would be a better comparison of $/kWh.

[Mike90250]

Comparisons have been left, but LFP centric topics moved to a new thread

http://www.solarpaneltalk.com/showthread.php?19238-LFP-battery-chatter

Mod

Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||

|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||

|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

[northerner]

Aquion Batteries

It sounds like these S20 stacks could work for many people who are off grid. The reality is that they would have to be sized for one's systems needs, much like is needed with any other battery type. If you have enough stacks in place, you can keep current flows down and the overall efficiency will be high(er). As a result you would be able to keep the DOD low as well and would get even more cycle life out of them. I believe they are rated for about 12000 cycles at a 25% DOD, correct me if I'm wrong? And they don't suffer a sudden death as many other batteries do when they do approach their cycle life. I don't know of any other battery that could compete with this? Couple that with no maintenance, cell balancing, electrolyte changes, etc... required!

It would be great to hear AHI users chime in. I realize they have just come out and there's not many in use at this point.

[Living Large]

It sounds like these S20 stacks could work for many people who are off grid. The reality is that they would have to be sized for one's systems needs, much like is needed with any other battery type. If you have enough stacks in place, you can keep current flows down and the overall efficiency will be high(er). As a result you would be able to keep the DOD low as well and would get even more cycle life out of them. I believe they are rated for about 12000 cycles at a 25% DOD, correct me if I'm wrong? And they don't suffer a sudden death as many other batteries do when they do approach their cycle life. I don't know of any other battery that could compete with this? Couple that with no maintenance, cell balancing, electrolyte changes, etc... required!

It would be great to hear AHI users chime in. I realize they have just come out and there's not many in use at this point.

They are too expensive, and their usable voltage range (30V - 59) does not align with off the shelf equipment. Can you get to with that restriction? I don't know.

You are going to use them at 25% DOD? If so, you've got a lot more money than I. And floor space. For me, that could cost $45,000. If 12000 cycles is correct (they advertise 4000 @ 80%, 6000 @ 50%). Maybe long term it works out - too many unknowns and expensive for me.

[bcroe]

They are too expensive, and their usable voltage range (30V - 59) does not align with off the shelf equipment. Can you get to with that restriction? I don't know.

You are going to use them at 25% DOD? If so, you've got a lot more money than I. And floor space. For me, that could cost $45,000. If 12000 cycles is correct (they advertise 4000 @ 80%, 6000 @ 50%). Maybe long term it works out - too many unknowns and expensive for me.

The point most seem to overlook, is doing lesser Depth of Discharge isn't saving much
money on batteries. Rather, you trade a high DOD on replacing fewer batteries more
often, against a lower DOD of a larger battery bank replaced less often. Just to compare,
12,000 cycles of 25% DOD is total energy stored over life of 3000 times batter capacity.
4000 cy times 80% = 3200. 6000 times 50% = 3000, they are all about the same lifetime
energy stored per battery $. Bruce Roe

[Sunking]

The point most seem to overlook, is doing lesser Depth of Discharge isn't saving much
money on batteries. Rather, you trade a high DOD on replacing fewer batteries more
often, against a lower DOD of a larger battery bank replaced less often. Just to compare,
12,000 cycles of 25% DOD is total energy stored over life of 3000 times batter capacity.
4000 cy times 80% = 3200. 6000 times 50% = 3000, they are all about the same lifetime
energy stored per battery $. Bruce Roe

Bruce the last 50% of capacity on Aquion battery is not usable once the voltage drops below 40 to 42 volts on a 48 volt system. The Ri of the Aquion battery is so high forces you to significantly over size the battery by 100%. They are completely useless IMHO, and because of that fact they will go bankrupt when the market discovers that fact. I waited 5 years for them to publish specs. What a disappointment. I really feel sorry for their customers.

[northerner]

They are too expensive, and their usable voltage range (30V - 59) does not align with off the shelf equipment. Can you get to with that restriction? I don't know.

You are going to use them at 25% DOD? If so, you've got a lot more money than I. And floor space. For me, that could cost $45,000. If 12000 cycles is correct (they advertise 4000 @ 80%, 6000 @ 50%). Maybe long term it works out - too many unknowns and expensive for me.

I agree that they are currently too expensive! Particularly, as a new technology, there is risk that they may not deliver as promised or problems could crop up over time. There is definitely a high up front cost with this product that will keep many potential users away.

The system I have is likely not near the size of yours, so the cost to install with 25% DOD would only be a fraction of that cost. Also, a significant price drop is planned at the end of this year from what I have read. I would expect the price to fall over time, just like any new product or technology that makes it's debut.

[northerner]

The point most seem to overlook, is doing lesser Depth of Discharge isn't saving much
money on batteries. Rather, you trade a high DOD on replacing fewer batteries more
often, against a lower DOD of a larger battery bank replaced less often. Just to compare,
12,000 cycles of 25% DOD is total energy stored over life of 3000 times batter capacity.
4000 cy times 80% = 3200. 6000 times 50% = 3000, they are all about the same lifetime
energy stored per battery $. Bruce Roe

The reason for the recommended lower DOD is prevent system voltage from dropping too low. Below 50% DOD, the voltage of the system could drop low enough with heavier loads to kick out your inverter. Larger storage will not see as significant a drop, and as you mention, you would not loose life time of the bank, as cycle life stays proportional to average DOD. Also, recharging the bank with solar will be more efficient, as currents during charging are on average higher than those during useage (ie during discharge)

[northerner]

Bruce the last 50% of capacity on Aquion battery is not usable once the voltage drops below 40 to 42 volts on a 48 volt system. The Ri of the Aquion battery is so high forces you to significantly over size the battery by 100%. They are completely useless IMHO, and because of that fact they will go bankrupt when the market discovers that fact. I waited 5 years for them to publish specs. What a disappointment. I really feel sorry for their customers.

Time will tell. I'm hoping they do work out and become a viable option for storage. Aquion just agreed to provide 1 mwh of storage to a major micro grid in Hawaii.

http://www.aquionenergy.com/press-room/press-releases/aquion-energy-enters-agreement-major-microgrid-battery-system-deployment

The bottom line is the overall cost of storage, which, if the specs they publish are true, could be the case!And at the same time they are environmentally friendly, which in itself, is a selling feature.

By the way, FLA's are also way over sized in order to provide a long life system. Many off grid users use only 20-30% average daily DOD!

[Sunking]

By the way, FLA's are also way over sized in order to provide a long life system. Many off grid users use only 20-30% average daily DOD!

That is not over sized. You have to have 2 to 3 days autonomy to CYA for cloudy days. To get the same usable autonomy using Aquion batteries would require twice the AH capacity at 8 times the cost.

A utility is designed by engineers who know what the batteries can and cannot do and thus the equipment is custom designed to work with the queer discharge curves and low C rate of the battery. The issue is two fold; economics and equipment compatibility. Aquion economics and compatibility do not work for consumer solar markets.