Lithium battery costs have fallen by 98% in three decades • Hacker News Board

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

#21

Post by natch » Sat, Apr 03, 2021, 5:37 PM UTC

f6v wrote: post #7

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

Very much depends on the home. Tesla Powerwall 2 seems to be 13.5 kWh at 114 kg. Energy consumption can be anything from 30 to 40[1]. So one Powerwall 2 unit probably won't get you through the day if you use that much. [1] https://www.eia.gov/energyexplained/use-of-energy/electricit...

Getting you through the day is not really the point though.

The point is

1) shifting some consumption during peak hours off of peak rates

and

2) having backup to get you through a limited outage, not necessarily at your full normal consumption level but without having to be in the dark / without internet / without phone and possibly car charging.

Nobody should evaluate this by whether one battery pack by itself provides all the energy anyone needs for everything with no limits. It’s one component with several good use cases.

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

#22

Post by ghaff » Sat, Apr 03, 2021, 5:37 PM UTC

turbinerneiter wrote: post #17

labawi wrote: post #12

Earlier quoted context omitted.

> 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.

Electric heat isn't super common, especially in standalone houses, in areas where you need a lot of heat in the US. I don't know the numbers off the top of my head but electricity costs a lot more than gas or oil. You're right about the AC but I still use 20 kWh even with no AC (and no electric heat).

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

#23

Post by reportingsjr » Sat, Apr 03, 2021, 5:40 PM UTC

brtkdotse wrote: post #20

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?

It does not, and the vast majority of people in the US have natural gas heating.

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

#24

Post by natch » Sat, Apr 03, 2021, 5:40 PM UTC

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.

The average US house is not the average house, nor is it representative of normal in the world we live in, which happens to dwarf the US by a factor of roughly 25.

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

#25

Post by quickthrowman » Sat, Apr 03, 2021, 5:41 PM UTC

ghaff wrote: post #11

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.

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 i…

> But, at the end of the day, I should still just get a propane-fueled generator at this point if I ever got anything.

Yes, a propane or natural gas generator is a lot more flexible/higher capacity

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

#26

Post by ghaff » Sat, Apr 03, 2021, 5:42 PM UTC

benjohnson wrote: post #18

labawi wrote: post #12

Earlier quoted context omitted.

> 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...

Yes, although the 30 kWh US figure doesn't include a lot of gas/oil heat in the North/mountains either. (It does include a lot of AC but average electricity consumption is still a lot higher apparently in the US even taking that into account. I assume bigger houses is one reason.)

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

#27

Post by turtlebits » Sat, Apr 03, 2021, 5:42 PM UTC

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

The wording in the article isn't great, but they are referring to the power consumption for a household in 1990.

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

#28

Post by BostonEnginerd » Sat, Apr 03, 2021, 5:42 PM UTC

brtkdotse wrote: post #20

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?

We use about 8500kWh per year in the northeast US. This does not include space heating yet, but does include our Chevy Volt charging.

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

#29

Post by wcarss » Sat, Apr 03, 2021, 5:43 PM UTC

brtkdotse wrote: post #20

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?

It's about 27kWh/day, and according to the stats in the link fv6 provided elsewhere in this threadset, that's average for a northeast US house. Houses in the south tend to use more like 15-16k kWh/year, due to air conditioning mostly, leaving the 2015ish national average for single detached homes closer to 13k kWh.

This post has been an interesting eye-opener for me. Somehow I've never really thought about the numbers deeply, but, having a 100-watt lightbulb on for 8 hours is almost 1kWh. My and my partners' computers + home server, at a mix of wattages and uses but mostly left on a lot, are probably using 15-20kWh daily. That's... a lot of power.

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

#30

Post by read_if_gay_ » Sat, Apr 03, 2021, 5:43 PM UTC

brtkdotse wrote: post #20

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?

10k kWh per year roughly corresponds to consuming a constant 1kW/h which sounds about right, if not a bit high, if you exclude heating. But I don't think electric heating is common in most places.