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Lithium battery costs have fallen by 98% in three decades

economist.com

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Re: Lithium battery costs have fallen by 98% in three decades

#11

Post by ghaff »

tyingq wrote: post #3
dragosmocrii wrote: post #2

The article says that today a battery pack the size of a backpack and that weighs about 40kg, can power a house for a day. Is that really so? Would that be a normal house, being powered for an entire day? I find it hard to believe that battery would pack that much energy

A Tesla Powerwall 2 weighs 114.0 kg and provides 13.5 kWh. Average US household electricity consumption is 877 kWh/month, which would be 29kWh/day. Either they mean a very efficient/small house, or homeowners with unusually frugal habits. Edit: Average UK household electricity consumption appears to be around 10kWh/day.

It also looks like a Powerwall 2 costs about $7,500 plus about another $5K for installation.

I use about 20kWh per day--I have a somewhat smaller house--and vaguely looked into whole house batteries a few months back and concluded they would only make sense if I had it wired into just a few critical systems like my furnace. But, at the end of the day, I should still just get a propane-fueled generator at this point if I ever got anything.

So $2K for a battery that can power a house for a day seems almost an order of magnitude off if they literally mean power an entire normal house.

Re: Lithium battery costs have fallen by 98% in three decades

#12

Post by labawi »

Tade0 wrote: post #6
dragosmocrii wrote: post #2

The article says that today a battery pack the size of a backpack and that weighs about 40kg, can power a house for a day. Is that really so? Would that be a normal house, being powered for an entire day? I find it hard to believe that battery would pack that much energy

40kg translates to 4-9kWh depending on the chemistry, meanwhile houses in the UK draw around 3kWh/day averaged over a year so unless a house is woefully inefficient, it checks out.

> Average US household .. 29kWh/day

> houses in the UK .. 3kWh/day

Seems believable from what I've heard.

Re: Lithium battery costs have fallen by 98% in three decades

#13

Post by ghaff »

Tade0 wrote: post #6
dragosmocrii wrote: post #2

The article says that today a battery pack the size of a backpack and that weighs about 40kg, can power a house for a day. Is that really so? Would that be a normal house, being powered for an entire day? I find it hard to believe that battery would pack that much energy

40kg translates to 4-9kWh depending on the chemistry, meanwhile houses in the UK draw around 3kWh/day averaged over a year so unless a house is woefully inefficient, it checks out.

Really? Houses in the US draw 10x on average relative to the UK? That seems unlikely.

ADDED: I can believe there's some difference because of AC but I basically don't have AC (just one window unit I run a few days a year), have oil heat, and have a somewhat smaller than average house but I still use about 20kWh/day.

The delta does seem to be real though.

Re: Lithium battery costs have fallen by 98% in three decades

#14

Post by marcosdumay »

300africans wrote: post #9
tyingq wrote: post #3

Earlier quoted context omitted.

A Tesla Powerwall 2 weighs 114.0 kg and provides 13.5 kWh. Average US household electricity consumption is 877 kWh/month, which would be 29kWh/day. Either they mean a very efficient/small house, or homeowners with unusually frugal habits. Edit: Average UK household electricity consumption appears to be around 10kWh/day.

Here in Burkina faso, I use between 5 and 12kwh per day with air con some months taking it close to 15kwh. If the price keeps coming down and with some solar installation, one can leave the grid in a couple of years time

I imagine most of the aircon energy usage coincides with the times of peak photovoltaic generation. So if you calculate by total energy consumption, you'll overestimate things by a huge margin.

Re: Lithium battery costs have fallen by 98% in three decades

#15

Post by dv_dt »

tyingq wrote: post #3
dragosmocrii wrote: post #2

The article says that today a battery pack the size of a backpack and that weighs about 40kg, can power a house for a day. Is that really so? Would that be a normal house, being powered for an entire day? I find it hard to believe that battery would pack that much energy

A Tesla Powerwall 2 weighs 114.0 kg and provides 13.5 kWh. Average US household electricity consumption is 877 kWh/month, which would be 29kWh/day. Either they mean a very efficient/small house, or homeowners with unusually frugal habits. Edit: Average UK household electricity consumption appears to be around 10kWh/day.

It’s enough for the twilight evening usage for a household when paired with a solar system.

Re: Lithium battery costs have fallen by 98% in three decades

#16

Post by 1cvmask »

Electricity consumption varies from household to household. Reminds me of this piece:

https://abcnews.go.com/Politics/GlobalWarming/story?id=29068...

“Armed with Gore's utility bills for the last two years, the Tennessee Center for Policy Research charged Monday that the gas and electric bills for the former vice president's 20-room home and pool house devoured nearly 221,000 kilowatt-hours in 2006, more than 20 times the national average of 10,656 kilowatt-hours.”

Re: Lithium battery costs have fallen by 98% in three decades

#17

Post by turbinerneiter »

labawi wrote: post #12
Tade0 wrote: post #6

Earlier quoted context omitted.

40kg translates to 4-9kWh depending on the chemistry, meanwhile houses in the UK draw around 3kWh/day averaged over a year so unless a house is woefully inefficient, it checks out.

> Average US household .. 29kWh/day > houses in the UK .. 3kWh/day Seems believable from what I've heard.

I think in the US it's common to heat and cool badly insulated houses with electricity, whereas in europe almost nobody cools, heat comes from other sources and insulation is taking way more seriously, especially for anything built recently.

The best way to reduce your energy bill (whichever source) is to live in the right climate zone I guess.

Re: Lithium battery costs have fallen by 98% in three decades

#18

Post by benjohnson »

labawi wrote: post #12
Tade0 wrote: post #6

Earlier quoted context omitted.

40kg translates to 4-9kWh depending on the chemistry, meanwhile houses in the UK draw around 3kWh/day averaged over a year so unless a house is woefully inefficient, it checks out.

> Average US household .. 29kWh/day > houses in the UK .. 3kWh/day Seems believable from what I've heard.

The 3kWh figure for UK is just electricity - add 12kWH for heating energy from gas to get a more reasonable number given that people in the UK generally don't live in shacks.

https://www.theenergyshop.com/guides/average-gas-and-electri...

Re: Lithium battery costs have fallen by 98% in three decades

#19

Post by adrianmonk »

tyingq wrote: post #3
dragosmocrii wrote: post #2

The article says that today a battery pack the size of a backpack and that weighs about 40kg, can power a house for a day. Is that really so? Would that be a normal house, being powered for an entire day? I find it hard to believe that battery would pack that much energy

A Tesla Powerwall 2 weighs 114.0 kg and provides 13.5 kWh. Average US household electricity consumption is 877 kWh/month, which would be 29kWh/day. Either they mean a very efficient/small house, or homeowners with unusually frugal habits. Edit: Average UK household electricity consumption appears to be around 10kWh/day.

Your point still stands, but there's probably some small correction factor necessary since the article seems to be talking about the weight of the cells only.

Although I'd bet the weight of the cells does make up the majority of the mass of a Powerwall, other components might have significant weight. From some quick, cursory research, it seems to have a metal frame/cover and apparently has some kind of liquid cooling. (Also, minimizing weight for a Powerwall seems less important than for an EV.)

Re: Lithium battery costs have fallen by 98% in three decades

#20

Post by brtkdotse »

1cvmask wrote: post #16

Electricity consumption varies from household to household. Reminds me of this piece: https://abcnews.go.com/Politics/GlobalWarming/story?id=29068... “Armed with Gore's utility bills for the last two years, the Tennessee Center for Policy Research charged Monday that the gas and electric bills for the former vice president's 20-room home and pool house devoured nearly 221,000 kilowatt-hours in 2006, more than 20 time…

10k kWh per year seems really low. Does that include heating?
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