More panels or more batteries?

[Sunking]

If you need 5 Kwh per day, then you need a 25 Kwh battery. You need to start over and educate yourself. Start by reading:

Solar Off-Grid Design
Battery Tutorial
Inverter/Battery Size

Do that and you will learn with 3 Sun Hours and 5 Kwh/day usable all you need is:

Panel Wattage = 2500 watts
48 Volt @ 520 AH
60 Amp MPPT Controller
Inverter Support up to 2500 watts maximum. Use as small of an Inverter that you can.

Takes me 5 seconds to design it.

[coinmaster]

Hmmm, how bout a couple of these sodium ion batteries. 2.6KW @48v for $1200 bucks https://www.altestore.com/store/deep...ck-48v-p11941/

100% usable DoD for an 8 year life span. 8 year warranty.

[Mike90250]

make sure that 120V Classic controller is still available in your ares, I think that was a discontinued model ??

[SunEagle]

Hmmm, how bout a couple of these sodium ion batteries. 2.6KW @48v for $1200 bucks https://www.altestore.com/store/deep...ck-48v-p11941/

100% usable DoD for an 8 year life span. 8 year warranty.

That type battery is still being tested for longevity based on it's DOD. But I am sure you will get support from altestore if the battery fails since Aquion is having financial problems.

[Amy@altE]

This don't make sense. 5000/2X5X1.2 /48 is =312.5AH, 12 volts is 1250AH also remember 1250 Ah with 24 hours is around 53 amps. even though 12 volts is not for a house system.

Sorry, typo, thanks for catching. I meant x2, not /2. I think I started writing /50%, then decided to say times 2 instead, ended up half way.

[Amy@altE]

make sure that 120V Classic controller is still available in your ares, I think that was a discontinued model ??

You are right Mike, that has been discontinued.
Please get 120V and 12V battery banks out of your head. 24V or 48V is the right way to go. Pushing too much power into the battery bank will kill the batteries, even with a charge controller. The charge controller can do a couple of things, some can limit the rate of current going into the battery bank, but that effectively is limiting your solar input. All will keep the battery bank from overcharging, but that is different from keeping you from pushing power into the bank too fast. (*Simplified explanation following, don't jump on me for details) Batteries store power by performing a chemical reaction. If you try making this reaction happen too fast, it will damage the batteries. This is why charge rate is important. A proper C/rate will allow the reaction to occur over a healthy period of time.

[Sunking]

Hmmm, how bout a couple of these sodium ion batteries. 2.6KW @48v for $1200 bucks 100% usable DoD for an 8 year life span. 8 year warranty.

Pure make believe and not suitable for solar. They must be charged and discharged very slowly.

[RedDenver]

Pure make believe and not suitable for solar. They must be charged and discharged very slowly.

Aquion's AHI batteries are not make believe and are being installed in a few places. And they don't have to be charged or discharged slowly, but they do have higher internal resistance than other battery types and will be less efficient at higher currents.

The AHI can handle partial states of charge, which may be a better fit for solar than efficiency metrics. However, as Suneagle mentions (and what I believe Sunking's hyperbole is referencing), the batteries do not have much field testing or customer experience. Also keep in mind that the smallest size available is the S-line battery stack, which is a bit over 3 ft tall and weighs 260 lbs and cannot be tipped (I think it's 15 deg but not sure) during shipment or installation, so you're going to need easy access and special handling to get the battery into place.

Edit: Amy@alte says the tipping restriction is now 45 deg. I'd strike out the text but there isn't a strikeout option in the editor.

[SunEagle]

Aquion's AHI batteries are not make believe and are being installed in a few places. And they don't have to be charged or discharged slowly, but they do have higher internal resistance than other battery types and will be less efficient at higher currents.

The AHI can handle partial states of charge, which may be a better fit for solar than efficiency metrics. However, as Suneagle mentions (and what I believe Sunking's hyperbole is referencing), the batteries do not have much field testing or customer experience. Also keep in mind that the smallest size available is the S-line battery stack, which is a bit over 3 ft tall and weighs 260 lbs and cannot be tipped (I think it's 15 deg but not sure) during shipment or installation, so you're going to need easy access and special handling to get the battery into place.

One of the Forum's members lives in Hawaii and is "testing" a rather large AHI at his off grid home. We haven't heard much back from him except the initial tests showed some success but more time was required before that battery could be considered a "viable" energy storage system for RE.

The sad part is that Aquion was having financial issues last year and the work force that made their batteries had been considerably reduced. Hopefully they do have some type of support for their systems being tested in the field.

[inetdog]

Pure make believe and not suitable for solar. They must be charged and discharged very slowly.

Note that in the Telecom industry and for other critical needs, anything that has not been in field use for at least 20 years is suspect.

[SunEagle]

Note that in the Telecom industry and for other critical needs, anything that has not been in field use for at least 20 years is suspect.

Well certainly not considered being 100% reliable.

[Amy@altE]

Also keep in mind that the smallest size available is the S-line battery stack, which is a bit over 3 ft tall and weighs 260 lbs and cannot be tipped (I think it's 15 deg but not sure) during shipment or installation, so you're going to need easy access and special handling to get the battery into place.

Aquion recently changed the shipping restriction. It can now handle a 45° tilt angle for no more than 1 hour duration.

[RedDenver]

One of the Forum's members lives in Hawaii and is "testing" a rather large AHI at his off grid home. We haven't heard much back from him except the initial tests showed some success but more time was required before that battery could be considered a "viable" energy storage system for RE.

The sad part is that Aquion was having financial issues last year and the work force that made their batteries had been considerably reduced. Hopefully they do have some type of support for their systems being tested in the field.

Not sure if the two are related but Aquion is transitioning to an automated manufacturing process. I think the technology has promise for stationary RE storage at low cost, but like all manufacturing startups, they need to cross the financial gulf between small sales and mass market.

[Sunking]

Aquion is not compatible as 60% of the energy is not available to the equipment. They have two huge strikes against them.

1. They must be charged and discharge very slowly which is not compatible with Solar. Solar demands to be charged at C/10 to C/4. Likewise discharged as high as C/4. Aquion cannot tolerate rates faster than C/20. The cells internal resistance is way too high. Only way to work around that issue is a much larger than needed battery capacity.

2. Charge/Discharge Curves are way outside equipment range. Example a 48 volt stack is 40 to 56 volts. Anything below 46 volts is not accessible. There are two ways to work around that. Again a much larger battery capacity than required. Second is for al equipment manufactures to redesign their equipment to work over that large of a voltage spread and that is not going to happen.

That is why they are going bankrupt.

[SunEagle]

Not sure if the two are related but Aquion is transitioning to an automated manufacturing process. I think the technology has promise for stationary RE storage at low cost, but like all manufacturing startups, they need to cross the financial gulf between small sales and mass market.

Until they can get the cost way down and prove the battery can be discharged as much as they claim IMO they are still in experimental stage.

The idea has merit but having a viable cost effective product is still a few years away.