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

The rise of batteries in six charts

rmi.org

Post reply on HN
Print view View original

171–180 of 275 posts

Re: The rise of batteries in six charts

#171

Post by inglor_cz »

conradev wrote: post #120
LUmBULtERA wrote: post #51

Earlier quoted context omitted.

Given the dramatically lower costs of utility-scale solar vs. residential rooftop solar, is it not better at a society level for state policy to incentivize utility over residential solar? Utility-scale battery installations likewise should be much cheaper.

Generally, yes, but a few items: - Distribution systems today can only handle some percentage of EV penetration in a given area, not 100%. Charging an EV from the roof skips the grid entirely - The bulk of the cost is labor and permitting, not the modules themselves. Given that, California requires solar on newly constructed homes - California updated their net metering program so that ratepayers aren’t subsidizing r…

"Charging an EV from the roof skips the grid entirely"

As long as you have enough sunshine hours in your region.

Southern Spain is fine year-round, but you won't get any meaningful output out of a solar panel in Finnish winter. The rest of Europe lies between those two extremes.

Northern winter will be made more challenging by addition of EVs to the grid, because a lot of electricity is being used for heating as well.

Re: The rise of batteries in six charts

#172

Post by tonymet »

antisthenes wrote: post #144
tonymet wrote: post #104

Earlier quoted context omitted.

why aren't consumers seeing this price yet?

Why would they? Companies will gladly pocket the difference between what they charge the customers and their $100/KWh bulk price.

Ok what's not working properly then?

Re: The rise of batteries in six charts

#173

Post by lancewiggs »

vel0city wrote: post #170
breischl wrote: post #137

Earlier quoted context omitted.

Works if you live in a first-floor, street-facing unit and can reliably park in front of it. Otherwise it can be tough. It's unfortunate that EVs make the most immediate sense in high-density urban settings, but those same settings have lots of people who can't use the simple kinds of charging infrastructure (eg, Level 1/2 chargers).

IMO EVs work best in medium density urban settings, where people still probably have their own garages or at least private parking spots but aren't likely to need to do 100+mi drives constantly. Truly high-density urban settings should ideally find transportation solutions without cars.

And stop using streets for car storage, opening them up to people and plants.

Re: The rise of batteries in six charts

#174

Post by ceejayoz »

tonymet wrote: post #163
ceejayoz wrote: post #110

Earlier quoted context omitted.

A quick check shows the 21 billion gallon number you're (not) citing is likely bullshit. https://www.verifythis.com/article/news/verify/environment-v... > David Checkel, a professor at the University of Alberta and an electric car expert, did some back-of-the-napkin math to dispute the claim. Checkel calculated that if each gallon of fuel costs $3, then 21 billion gallons would cost $63 billion annually. If $63 billi…

what's the correct figure? it's easily 100x the output

Is that number pulled off a Facebook meme, too?

You seem confused by the concept of a reusable battery. It's not a AA battery; you don't throw it away every 300 miles and get a new one.

Re: The rise of batteries in six charts

#175

Post by mbgerring »

ghaff wrote: post #64
LUmBULtERA wrote: post #51

Earlier quoted context omitted.

Given the dramatically lower costs of utility-scale solar vs. residential rooftop solar, is it not better at a society level for state policy to incentivize utility over residential solar? Utility-scale battery installations likewise should be much cheaper.

Residential solar may still make sense for new construction (maybe?) in the right areas. But there was a lot of scammy behavior around home solar installation at one point. Given that home solar does not effectively give you a backup generator for free (barring a lot of batteries and specific electrical hookups as I recall), it's not clear it's a big win in general. A lot of utility things aren't ideal at the individ…

A lot of home solar installers now include grid tied batteries as part of a standard installation, which is what NEM 3 was intended to do (secondarily, after its primary goal of giving CA IOUs a massive free lunch).

Re: The rise of batteries in six charts

#176

Post by stcredzero »

breischl wrote: post #137
stcredzero wrote: post #112

Earlier quoted context omitted.

I cannot reasonably run lengths of 110v extension cords down the block to charge a car overnight I used to run extension cords out of windows and across the sidewalk to charge a Fiat 500e.

Works if you live in a first-floor, street-facing unit and can reliably park in front of it. Otherwise it can be tough. It's unfortunate that EVs make the most immediate sense in high-density urban settings, but those same settings have lots of people who can't use the simple kinds of charging infrastructure (eg, Level 1/2 chargers).

Works if you live in a first-floor, street-facing unit

I was not exactly in that situation. First time, I lived in a room on the 3rd floor of a house, but I'd run the extension cord out of the house owner's workshop basement window. I could reliably park in front of the house, however.

2nd time, I ran the cord out of a 2nd story window from my room, but the parking space was behind the house's fence under my window.

3rd situation, I would run the cord from the apartment exercise room, out the window to the fenced in parking lot behind the building. However, the building management actually removed those outlets! Then, that law requiring them to let us charge passed, but by then, it was time for us to move out. Now, I have a garage of my own!

Re: The rise of batteries in six charts

#177

Post by mbgerring »

tonymet wrote: post #55
sixstringtheory wrote: post #15

This is a great set of charts and analysis, although I have two problems with it. 1. On the chart of energy density, I'd like to see the the energy density of petrol for comparison. It's much higher, and even though extrapolation is dangerous, I'd like to see how long it could take to reach parity given some of the different forecasting models they mention. Specifically regarding their mention of air travel, I'd like…

Lithium Battery 0.5 kWh/kg Diesel 12.7 kWh/kg

Who cares, we need to stop burning fossil fuels, relative energy density in the abstract does not matter in the context of climate change

Re: The rise of batteries in six charts

#178

Post by mbgerring »

xbmcuser wrote: post #115

This is why I say electricity revolution is coming and a lot people and countries are going to be shell shocked by it. Solar and wind electricity costs are also decreasing at a similar rate.

It’s already here, it’s been here for a decade, renewables are a mature industry. They’ve already effectively destroyed the economics of coal, and natural gas is next.

Re: The rise of batteries in six charts

#179

Post by mbgerring »

Phenomenit wrote: post #39
bryanlarsen wrote: post #5

Earlier quoted context omitted.

It's difficult to see any of the alternatives displacing batteries for short-term storage. Batteries aren't a good fit for long-term storage, which is where alternatives should be competitive. But that market is essentially 0 right now.

What is the use case of long term storage in batteries? As some kind of reserve?

“Long term” in industry parlance means “greater than 8 hours”

Re: The rise of batteries in six charts

#180

Post by vel0city »

nerdbert wrote: post #162
thelastgallon wrote: post #20

Earlier quoted context omitted.

> I'd like to see the the energy density of petrol for comparison. Petrol's higher energy density doesn't matter as much as people think. Electric vehicles are around four times as efficient as petrol. In a petrol car, only 20% of the energy is converted to motion. In electric cars, this is around 80% (with some variation dependent on regenerative braking). I wrote about this extensively in a previous article: https:…

> In a petrol car, only 20% of the energy is converted to motion. In electric cars, this is around 80% How does it settle out when you take into account the significantly higher weight of EVs?

By "significantly heavier" it is often a difference of a few hundred pounds on a few thousand pound vehicle. A 2L engine is about 400lbs, an automatic transmission is another 220lbs, 20 gallons of gas is 120 lbs, add another 100ish pounds for a much larger cooling system. So sure, the battery is like 1,000lbs but you traded 840 pounds for 200 pounds of EV motors (assuming two of them!) so in reality you're up like 360lbs.

Combined with regenerative braking, it doesn't make that big of difference in total energy usage. A massive chunk of the energy used in an EV is aero drag which makes little difference about weight. Weight makes a bigger impact with stop and go traffic on non-regen cars as slowing down that extra mass turns more energy into heat. An object in motion wants to stay in motion and all, once you're up to speed you're using about the same energy. This is why a lot of the EV trucks have close to the same range if the bed is full or not assuming it has the cover on the bed, but towing even a small trailer becomes a massive range hit.

I get on average 3.5mi/kWh in my EV, ~1MJ/mi. A gallon of gas is like 120 MJ, an average hybrid will get like 40mpg, so 3 MJ/mi being burned. You'd need to get like 120mpg to match my average efficiency of energy usage, and my EV isn't even that incredibly efficient of an EV.

Post reply on HN