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Falling lithium-ion battery prices to drive rapid storage uptake

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Re: Falling lithium-ion battery prices to drive rapid storage uptake

#21

Post by sp332 »

merpnderp wrote: post #3
nabla9 wrote: post #2

$200/kWh by 2019. Assuming that households consume between 30 kWh and 15 kWh electricity daily on average and you want to have storage capacity for 1/3 of daily electricity consumption to get wind or solar energy work, you need 10-5 kWh per household. That's $2000 - $1000 per household. If that battery lasts 10 years, its $200 - $100 per year. It's workable and scales if we are able to reuse lithium. When does that h…

That wouldn't work for much of the South where summer usage for a house can easily hit 100 kWh/day for air conditioning. The hottest part of the day usually starts at about the end of the prime solar hours. Plus you'll want massive overcapacity of your batteries as deep discharges drastically reduce their useful lifespan.

It's only prime solar hours if you point your solar panels due south. That gets you a higher figure on paper, but if you need the power later in the day you could point them a bit more to the west and get a lot more usable power when you need it. With solar panel prices falling, it's a race to see if it's cheaper to over-provision solar panels or batteries.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#22

Post by djrogers »

zAy0LfpBZLC8mAC wrote: post #11
merpnderp wrote: post #3

Earlier quoted context omitted.

That wouldn't work for much of the South where summer usage for a house can easily hit 100 kWh/day for air conditioning. The hottest part of the day usually starts at about the end of the prime solar hours. Plus you'll want massive overcapacity of your batteries as deep discharges drastically reduce their useful lifespan.

I would think that for that use case, using thermal storage should be more efficient? Don't store electricity to run AC later, but run AC to cool down water or the ground beneath your house or something, and then cool your house with that later.

That would require a huge amount of work and expense, and at the end of the day cold water isn’t very good at cooling off giant masses of air and furniture.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#23

Post by lossolo »

EngineerBetter wrote: post #14
merpnderp wrote: post #3

Earlier quoted context omitted.

That wouldn't work for much of the South where summer usage for a house can easily hit 100 kWh/day for air conditioning. The hottest part of the day usually starts at about the end of the prime solar hours. Plus you'll want massive overcapacity of your batteries as deep discharges drastically reduce their useful lifespan.

Wow - that's a crazy amount of energy. As a Brit who's never been the south of the US, is that figure really true? 100kWh is about 300 miles in a Tesla, or boiling a kettle constantly for about 30 hours. If that's really accurate, then I'm staggered at how much energy folks must be using to keep cool, and makes my efforts at saving energy seem paltry in comparison.

It's 24/7 air conditioning working. In EU you get around 100kWh per day also if you use home air condition 24/7.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#24

Post by wlesieutre »

dangoor wrote: post #17
mavhc wrote: post #12

I paid $354/kWh last month for 24kWh of batteries (inc 20% tax), and I got a free car that goes around it

What kind of electric car costs $8500? Used Leaf?

I heard from a friend that the Leaf's battery pack had a major redesign of the cooling system in recent models, that might have driven down the value of used older versions with worse anticipated battery wear.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#25

Post by epistasis »

ptero wrote: post #18
epistasis wrote: post #7

Earlier quoted context omitted.

GW is, however, a characteristic of an energy storage system, and just a valid and important measurement as the amount of energy it stores.

Maximum discharge speed (which is one of the very few storage characteristics I can think of to be measured in GW) is pretty much irrelevant for storage systems. Add a few quick discharge capacitors that cost almost nothing and boom -- your max discharge speed shoots through the roof (but speed goes down for a very short time). Maybe sustained charge speed is a (little bit) more meaningful thing you can express in GB…

Your instincts would be wrong on this one. This is a technical article, that talks about all the right things for grid storage: value stacking, $/kWh (note the h), various install locations such as behind-the-meter, etc. They know what they are talking about.

Currently, grid discussions happen mostly in the MW or GW space. Maximum instantaneous discharge speed is pretty much the most important characteristic for storage, up until very very recently, since it was mostly used for frequency regulation. Lately more and more articles are discussing total energy capacity instead, as this is discussed in wider circles than just those interested in the grid. Also note that the duration of discharge for a storage system is often implicit because it is deployed in an energy market where the bids are on fixed time periods (e.g. 4h).

Ideally we'd know both the GWh and the GW, but the collated stats have been mostly GW so far.

Guessing that they don't understand GWh vs. GW is pretty far off base. Though this may be a confusion of units that happens often in discussion with lay folk, it's not much of a concern when talking to people that are discussing the grid.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#26

Post by mavhc »

wlesieutre wrote: post #24
dangoor wrote: post #17

Earlier quoted context omitted.

What kind of electric car costs $8500? Used Leaf?

I heard from a friend that the Leaf's battery pack had a major redesign of the cooling system in recent models, that might have driven down the value of used older versions with worse anticipated battery wear.

Yeah, that's why I got the 2014 version. Turns out it also had the 6.6kW charger, even though it wasn't advertised as such, that was nice. You'd think the Nissan dealer would know something about the cars they were selling.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#27

Post by [deleted] »

wlesieutre wrote: post #24
dangoor wrote: post #17

Earlier quoted context omitted.

What kind of electric car costs $8500? Used Leaf?

I heard from a friend that the Leaf's battery pack had a major redesign of the cooling system in recent models, that might have driven down the value of used older versions with worse anticipated battery wear.

[deleted]

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#28

Post by OtterCoder »

EngineerBetter wrote: post #14
merpnderp wrote: post #3

Earlier quoted context omitted.

That wouldn't work for much of the South where summer usage for a house can easily hit 100 kWh/day for air conditioning. The hottest part of the day usually starts at about the end of the prime solar hours. Plus you'll want massive overcapacity of your batteries as deep discharges drastically reduce their useful lifespan.

Wow - that's a crazy amount of energy. As a Brit who's never been the south of the US, is that figure really true? 100kWh is about 300 miles in a Tesla, or boiling a kettle constantly for about 30 hours. If that's really accurate, then I'm staggered at how much energy folks must be using to keep cool, and makes my efforts at saving energy seem paltry in comparison.

Remember, the south of the US is in the subtropics, roughly level with the north of Africa. Imagine living in Egypt and not running the AC constantly.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#29

Post by catawbasam »

EngineerBetter wrote: post #14
merpnderp wrote: post #3

Earlier quoted context omitted.

That wouldn't work for much of the South where summer usage for a house can easily hit 100 kWh/day for air conditioning. The hottest part of the day usually starts at about the end of the prime solar hours. Plus you'll want massive overcapacity of your batteries as deep discharges drastically reduce their useful lifespan.

Wow - that's a crazy amount of energy. As a Brit who's never been the south of the US, is that figure really true? 100kWh is about 300 miles in a Tesla, or boiling a kettle constantly for about 30 hours. If that's really accurate, then I'm staggered at how much energy folks must be using to keep cool, and makes my efforts at saving energy seem paltry in comparison.

Yes, that is a crazy amount. I live in the South, and the highest we hit is about 35kWh on extremely hot weekend days. Our typical summertime use is more like 20kWh/day -- but according to our utility, we're using about 1/2 of what a typical neighbor uses.

Based on this very scientific single-neighborhood sample, I'd guess 40-60kWh/day would not be unusual during the peak summer months.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#30

Post by jessriedel »

2sk21 wrote: post #20
EngineerBetter wrote: post #14

Earlier quoted context omitted.

Wow - that's a crazy amount of energy. As a Brit who's never been the south of the US, is that figure really true? 100kWh is about 300 miles in a Tesla, or boiling a kettle constantly for about 30 hours. If that's really accurate, then I'm staggered at how much energy folks must be using to keep cool, and makes my efforts at saving energy seem paltry in comparison.

I live in New Jersey and just had solar panels installed on my roof. Peak power is about 7.8 KW. On clear days, power production in the summer is about 50 kWh I have been keeping daily logs this summer and find that my daily power consumption swings between about 25 kWh on cool days to 65 kWh on really warm days. Definitely a lot lower than 100 kWh mentioned previously.

Needless to say, NJ is very different the South, and in any case this is highly dependent on the size of the house and the amount of insulation.
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