Price Point of lifepo4 batterys.

[NiHaoMike]

After losses, just breaking even is going to be difficult. Natural gas might be viable if it's cheap enough in the area.

Excluding heating/cooling devices (where thermal storage would likely make a lot more sense), I'm having a hard time thinking of a 2kW residential load that would regularly run for at least 5 hours at a time, except for a crypto mining machine.

[SiliconWizard]

You can take a look there: http://www.batteryspace.com/96v-lifepo4-battery-packs.aspx
You have to ask for a quote i think.

For 10 kWh, it's most likely going to be over $5000.
Ouch.

i can buy 10kW for $3800 without any trouble... Still too high a price point i think.

For proper LiFePo4 batteries? Where?

I'd really suggest not taking any chances and buying from very reputables sources. A 10 kWh battery pack catching on fire or exploding will not be pretty.

[f4eru]

Thundersky : 0.26 Euro / Wh
GS : 0.39 Euro / Wh

This is for big prismatic cells,  so the assembling cost is smaller than for a huge pile of 18650s

[mrpackethead]

You can take a look there: http://www.batteryspace.com/96v-lifepo4-battery-packs.aspx
You have to ask for a quote i think.

For 10 kWh, it's most likely going to be over $5000.
Ouch.

i can buy 10kW for $3800 without any trouble... Still too high a price point i think.

For proper LiFePo4 batteries? Where?

I'd really suggest not taking any chances and buying from very reputables sources. A 10 kWh battery pack catching on fire or exploding will not be pretty.

LifePO4 is not likely to explode. Different chemistry from lion

Have bought many hundreds of smaller packs from this supplier and they are good
( solar charge remote small loads )

Even at 3800 it’s too spendy without solar

[splin]

Thundersky : 0.26 Euro / Wh
GS : 0.39 Euro / Wh

This is for big prismatic cells,  so the assembling cost is smaller than for a huge pile of 18650s

0.26 Euro/Wh is approx $0.3/w/h or $1/Ah which is exactly the same price as when I was looking 8 to 10 years ago.

It seems odd that we're continually being told that battery prices have been plummeting exponentially, and will continue to do so, for many years.To be fair I assume they are referring to Li-ion cells but even they still seem to quite expensive at around $0.28/Wh (when bought in quantities of 100 or more) but have much poorer cycle life of a few hundred compared to 2 or 3 thousand for LiFePO4. I guess there is simply not enough demand for LiFePO4 cells to stimulate enough competition to drive prices down.

$0.3/Wh gives a lifetime cost of $0.19/kWh for the battery alone (given 2000 80% discharge cycles) which is no cheaper than grid electricity.

Does anyone know what real-world cycle life expectations are for current LiFePO4 and Li-ion cells are? LiFePO4 cells hadn't been around long enough for the manufacturer's claims to be proven when I last looked a few years ago. Also, most users of these cells were for EV applications which stress the cells much more than in renewable applications, so their cell life experience is not directly applicable.

[hendorog]

Yes, lots of analysis. The big issue is that when you are buying power on the spot market ( wholesales ) pricing can vary signficantly and in a erratic way.   If a power station drops of the grid the spot price can go through the roof really quickly..

My average price for power is around 0.08/kWh  ( plus fixed transmission costs of around 0.09/kWh ).   It has dropped as low as 0.02 and sometimes peaks ( for quite short periods ) over 0.70.   

I really want to be able to cover myself for 4-5 hours at 2kW.  ( essentially i dont' want to make much in the way of lifestyle change ).. so when it does peak out, i can self supply.

But right now, at the battery prices is not actually breaking even.

Hehe, I went down this rabbit hole. I am also on spot pricing with Flick. Just couldn't make it economic. I don't think our pricing is as good as yours though.
When I first looked at it it seemed as simple as covering the AM and PM peak's with battery power. But since then the pricing has been more consistently high, even overnight, and spiking has become rarer.

Having said that the spikes a few days ago cost us $15 - $20, which is significant as the weekly bill is about $40.

I think a new battery chemistry is required, one that is cheaper can handle many cycles and high current. Upside is that it doesn't need to be dense and light as Lipo/Lifepo4.

[NiHaoMike]

LiMn (what the Nissan Leaf uses) seems to be "good enough" for a lot of applications that LiFePO4 was thought to be ideal for.

[hendorog]

LiMn (what the Nissan Leaf uses) seems to be "good enough" for a lot of applications that LiFePO4 was thought to be ideal for.

Is it cheap enough?

[NiHaoMike]

Is $200/kWh cheap enough for you? Or less in bulk?

[hendorog]

Is $200/kWh cheap enough for you? Or less in bulk?

Yes that would work for me as a DIY, assuming I could get them here close to that price.
But that wouldn't be cheap enough for a 'production' product as it wouldn't leave much room for making a profit.

I was thinking of 2-4kWh unit, which would just kick in to eliminate draw from the grid during price spikes.

[metrologist]

Is $200/kWh cheap enough for you? Or less in bulk?

That is interesting, but where are you seeing this? I looked at some used/referb cells and was not confident I'd get enough cycles to break even.

[NiHaoMike]

Is $200/kWh cheap enough for you? Or less in bulk?

That is interesting, but where are you seeing this? I looked at some used/referb cells and was not confident I'd get enough cycles to break even.

That's the going rate for Nissan Leaf battery modules. You can get a better price if you're willing to wait for a deal on a whole pack.

[hendorog]

Is $200/kWh cheap enough for you? Or less in bulk?

That is interesting, but where are you seeing this? I looked at some used/referb cells and was not confident I'd get enough cycles to break even.

That's the going rate for Nissan Leaf battery modules. You can get a better price if you're willing to wait for a deal on a whole pack.

New or used?

[NiHaoMike]

That's the going rate for Nissan Leaf battery modules. You can get a better price if you're willing to wait for a deal on a whole pack.

New or used?

Used, but whole packs will state their age and mileage. The individual modules are easy to test. Note that EV use is very demanding on internal resistance so they'll remain useful for lower current applications long after they're no longer useful for an EV.

Rinoa Super-Genius has done a few videos on Nissan Leaf batteries, including how to tear down a pack.

[metrologist]

is there any data on actual remaining capacity and useful cycles, for low current applications? I hesitate because they seem like spent cells. I saw used 7.6V cells for $50US on ebay.

[NiHaoMike]

There are a lot of posts on DIY EV sites regarding those.

[mrpackethead]

Hehe, I went down this rabbit hole. I am also on spot pricing with Flick. Just couldn't make it economic. I don't think our pricing is as good as yours though.

i'm in Wellington, where are you?    REmember my 0.07 is excluding transmission costs.   I'm also with flick and i am on the win with them, over any of the fixed price suppliers..  It does seem tough when you get those 80c peaks!   Even at $3800 for 10kWhr i can't make it ecomomic at this point.  Interestingly however Flick now lets you sell power back into the grid at the spot rate.   So,  if you had surplus power while the peaks where there, you might be on a win..

However on the whole, putting any solar power into batterys right now does'nt stack, unless i was using it to charge an electric car.    ( because you have to put the power in there anyway ).

I was reading about generating methane, I wonder what the energy losse's in that are. Expect quite high.

When I first looked at it it seemed as simple as covering the AM and PM peak's with battery power. But since then the pricing has been more consistently high, even overnight, and spiking has become rarer.

Having said that the spikes a few days ago cost us $15 - $20, which is significant as the weekly bill is about $40.

I think a new battery chemistry is required, one that is cheaper can handle many cycles and high current. Upside is that it doesn't need to be dense and light as Lipo/Lifepo4.

[hendorog]

Hehe, I went down this rabbit hole. I am also on spot pricing with Flick. Just couldn't make it economic. I don't think our pricing is as good as yours though.

i'm in Wellington, where are you?    REmember my 0.07 is excluding transmission costs.   I'm also with flick and i am on the win with them, over any of the fixed price suppliers..  It does seem tough when you get those 80c peaks!   Even at $3800 for 10kWhr i can't make it ecomomic at this point.  Interestingly however Flick now lets you sell power back into the grid at the spot rate.   So,  if you had surplus power while the peaks where there, you might be on a win..

However on the whole, putting any solar power into batterys right now does'nt stack, unless i was using it to charge an electric car.    ( because you have to put the power in there anyway ).

I was reading about generating methane, I wonder what the energy losse's in that are. Expect quite high.

When I first looked at it it seemed as simple as covering the AM and PM peak's with battery power. But since then the pricing has been more consistently high, even overnight, and spiking has become rarer.

Having said that the spikes a few days ago cost us $15 - $20, which is significant as the weekly bill is about $40.

I think a new battery chemistry is required, one that is cheaper can handle many cycles and high current. Upside is that it doesn't need to be dense and light as Lipo/Lifepo4.

North Shore - i.e. Aucklands bastard child It was funny watching the council work out all of the things they needed to do after they killed all of the ND contracts when the super city amalgamation happened.

Do you mean generate gas using a digester? If so it's basically free so losses don't matter much does It?

[mrpackethead]

No, make methane from surplus electrcicty, and then burning it later...

[hendorog]

No, make methane from surplus electrcicty, and then burning it later...

Surely you would just make methane from any old crap, grass clippings, whatever. There is no way to beat that.

[NorthGuy]

SLA batteries are much cheaper and probably last longer.

The efficiency may be a problem. You need to convert AC->DC, then DC->AC, plus battery losses. With LiFePO4 battery losses are small. SLA efficiency is worse. However, Inverter/Charger losses are unavoidable either way. This will only save money if the price difference is really big.

[hendorog]

SLA batteries are much cheaper and probably last longer.

The efficiency may be a problem. You need to convert AC->DC, then DC->AC, plus battery losses. With LiFePO4 battery losses are small. SLA efficiency is worse. However, Inverter/Charger losses are unavoidable either way. This will only save money if the price difference is really big.

Hmm, I think it is not as cut and dried as that. I just did some quick calcs based on _local_ pricing and even flooded LA loses out to the Leaf modules. I am allowing for a 50% DOD limit for LA which changes the game. Better/worse pricing can no doubt be found, and the Leaf modules are OOS anyway.

I agree on the lifetime though. For a small 2 or 3 kWh pack like I want its not a big deal using the second hand cells.
However for a large capacity off grid pack I'd be looking for new cells to get a warranty.

Nissan leaf module price from here: https://bluecars.nz/shop/battery-module-leaf-gen1-24kwh/
48 Ah @ 7.6V = 364.8 Wh
$125/364.8Wh = 0.343 $/Wh

Flooded LA battery price from here: https://www.batteryworx.co.nz/collections/best-deep-cycle-battery/products/crown-6v-220ah-deep-cycle-battery
220Ah @ 6V = 1320 Wh
$349/1320 = 0.264 $/Wh

However since DoD is 50%, factor of 2 penalty for LA:
$349/660 = 0.529 $/Wh

Also I would need to consider how many batteries I'd need to parallel up so I can get the power out of it. This would mean I'd need to go for several smaller LA batts instead of a couple of large ones, which will make the pricing worse.

Bear in mind this the pricing is in NZD (multiply by 0.7 to get USD), with little effort made to find the best price. They will be doubt be higher than what you are used to seeing as stuff costs more here.

[NorthGuy]

I just did some quick calcs based on _local_ pricing and even flooded LA loses out to the Leaf modules.

When you buy batteries, you pay for the lifespan. Look, for example, at Trojan T-105 from your store. Why do you think they're more expensive? Because they'll last longer. A battery can store so many kWh through its life. If you look at the datasheets, you can figure how many kWh you can store before the battery wears out (depending on how you use it). If you then re-calculate price per kWh, you'll see that T-105 is actually cheaper.

If you buy a used battery, part (most?) of the useful battery life is gone, you only get what remains, possibly next to nothing. That's why your Nissan packs are so cheap. If you go to a local golf-course, I'm sure they'll sell you used SLA batteries for very little, but such batteries will not have much left in them, so they're worth very little.

[hendorog]

I just did some quick calcs based on _local_ pricing and even flooded LA loses out to the Leaf modules.

When you buy batteries, you pay for the lifespan. Look, for example, at Trojan T-105 from your store. Why do you think they're more expensive? Because they'll last longer. A battery can store so many kWh through its life. If you look at the datasheets, you can figure how many kWh you can store before the battery wears out (depending on how you use it). If you then re-calculate price per kWh, you'll see that T-105 is actually cheaper.

If you buy a used battery, part (most?) of the useful battery life is gone, you only get what remains, possibly next to nothing. That's why your Nissan packs are so cheap. If you go to a local golf-course, I'm sure they'll sell you used SLA batteries for very little, but such batteries will not have much left in them, so they're worth very little.

Yes of course - and that is the 'risk' part of the equation. With the top end battery you get a warranty. With the warranty most decent manufacturers are incentivised to make them go the distance.
Of course they put many limitations around the warranty. Ensuring compliance with the warranty conditions all of the time may be difficult in an experimental type setup like the one being discussed.

I'm just saying that on a small scale it might be worth the risk. I'd need some way of working out the health of the modules.

[mrpackethead]

Rough is this fesible math.

Heres the 1/2 hour spot market price sorted into price bins of sorts..
 
At USD $400/kwH for batterys,  lets assume 3000 cycles to 80%,  we can get 20,000kWh out of a 10kWh battery pack over its life. .  Thats goign to cost me $NZD 0.10c per unit for the battery.

There is no savings to be made by using the battery to provide power until the unit cost of power is > average + 0.10c   or in our case;  16.7c units.       We should never charge the batterys if power is greater than average cost;

The average cost of 'peak priced power ) is 24.8c

There were 974 hours over the dataset that exceeded that ( 1489 days )..  or 2.7% of the time. 87% of the peaks that are greater than 16.7c are less than 2 hours wide.   My household use does tend to use power in line with the peaks, and i use 1.4kWhr/hrs on average during the peak.  ( i already ditch non essential loads ).       5kWh of storage probably will suffice, which will cost me about $2000USD ( $2800 NZD )

My potnetial savings over a year,  are 236hours * 1.4kW ( 24.8 - 6.7c )  =  $59.80!!!!    Factor in the 'cost' of the battery.. its just $26.76 per year im ahead.        If i factor in cost of money at say 4.9%,,  ( 2800 * 4.95 ) = $138 / year.  I'm down $110 a year for the hassle.


Conclusion: putting a battery in byitself to round off the peak power prices, has negetive economic benefit.




The next scenerio to consider is see what impact putting a sensible sized solar system in is along with the Batteries.     Power generated locally is going to have an 9.8c advantage over anything that is imported as it wont' attract any distribution fees.     I can also 'sell' surplus power back into the grid at the same rate as i buy it for ( the spot rate ).

 
I use about 1200kW per month on average. We only increase useage slighly during winter.   The bulk of useage will fall outside of the peak solar production hours.