Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Lithium battery costs have fallen by 98% in three decades

economist.com

Post reply on HN
Print view View original

51–60 of 424 posts

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

#51

Post by bcrosby95 »

turbinerneiter wrote: post #37
ghaff wrote: post #22

Earlier quoted context omitted.

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).

Thanks for the insight. I vaguely remembered that people run the ac in reverse for heat, but that is probably only in paces that almost need no heating. Do you know why you use that much? Do you heat your water with electricity? Fridge, freezer, tv, WiFi, Desktop PC, charging phones and laptop, ligths.

AC is extremely efficient for what it's doing, but it only works because the temperature difference is relatively minor. Where they can get away with it, they use something similar to AC for heating in the US.

But it doesn't work everywhere for heating. Consider that even in the hottest climates in the US, you're cooling your air by 30 degrees. But in the coolest climates, you're heating your air by 60 degrees.

My sister has this system in Philadelphia, but when it gets cold enough the more inefficient raw electric heating kicks in, and that really chews through electricity like no other.

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

#54

Post by rconti »

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.

No way. 90kWh/month?

My Silicon Valley house consumed ~450kWh/month (15kWh/day) (before we bought an EV) which is very much on the low side from what I see here. 1100sqft. No A/C. Rarely run the heat. Every single light in the house is an LED. Gas appliances. 2 people, not home during the day.

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

#55

Post by tyingq »

natch wrote: post #24
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.

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.

I don't assume they mean something smaller than a factor of 25 either. 1.2kWh would be substantially less than 40kg.

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

#56

Post by umvi »

Someone wrote: post #8
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.

Or houses not in the USA. http://shrinkthatfootprint.com/average-household-electricity... : “The average American or Canadian household in 2010 used about twenty times more than the typical Nigerian household, and two to three times more than a typical European home”

Why is that? Is it because North Americans use electricity for cooking and heating whereas other countries use gas for that?

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

#57

Post by jccooper »

spockz wrote: post #41
natch wrote: post #21

Earlier quoted context omitted.

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 provi…

I’m not sure about regulations in the US but in The Netherlands you cannot just attach a battery and think you are independent of the grid. To protect the net and people working on the net, power sources behind the meter must disengage when the net/mains power drops. This effectively disables your independence plan. If you want to be independent you have to get some expensive mechanism installed that will decouple yo…

Transfer switches are standard for pretty much any generator setup. An automatic one is a bit more expensive, but hardly a deal breaker.

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

#58

Post by tyingq »

umvi wrote: post #56
Someone wrote: post #8

Earlier quoted context omitted.

Or houses not in the USA. http://shrinkthatfootprint.com/average-household-electricity... : “The average American or Canadian household in 2010 used about twenty times more than the typical Nigerian household, and two to three times more than a typical European home”

Why is that? Is it because North Americans use electricity for cooking and heating whereas other countries use gas for that?

I suspect big houses, poor insulation, air conditioning, and gluttony.

Most of the US houses I've been in use either gas or fuel oil for heating.

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

#59

Post by fwsgonzo »

umvi wrote: post #56
Someone wrote: post #8

Earlier quoted context omitted.

Or houses not in the USA. http://shrinkthatfootprint.com/average-household-electricity... : “The average American or Canadian household in 2010 used about twenty times more than the typical Nigerian household, and two to three times more than a typical European home”

Why is that? Is it because North Americans use electricity for cooking and heating whereas other countries use gas for that?

Probably due to differences in standards, like wall isolation (I don't know the english terms). My house has 25cm isolation in the walls and 40cm isolation under the roof. I also have 3-layer windows and a thick metal door. The ventilation system is isolated and the air heat is reused to save electricity. This is for a 260sqm house.

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

#60

Post by maxerickson »

ghaff wrote: post #13
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.

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.

My highest months come out to less than 10 kWh per day. This is work from home + running the furnace (blower and pumps) and running a humidifier. Lots of months will be less than 200 KWh total.

This is a medium size house in a colder region of the US.

Do you have an electric hot water heater? That would probably boost my use a lot.

Post reply on HN