Gravity batteries try to beat chemical ones with winches, weights, mine shafts • Hacker News Board

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#31

Post by ardit33 » Sat, Apr 24, 2021, 7:19 AM UTC

guerby wrote: post #21

"But Schmidt’s calculation of the lifetime cost per megawatt-hour for lithium-ion batteries, $367, is more than twice as much" This is ridiculous. I'm charging right now my EV from a 14 kWh 16S LFP pack which costed me $1400 tax paid and delivered. LFP properly managed will do minimum 3000 cycles, so that's 42 MWh for $1400 which gives $34 per MWh out of the battery. Note: 5kW 48V inverter cost $500.

It is over 25 years, I don't think your battery will last 25 year. You probably have to replace it 3-4 times over that period of time. A mechanical system can last that much, even more, with minimal maintenance.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#32

Post by dang » Sat, Apr 24, 2021, 7:21 AM UTC

Past related threads:

Gravity Energy Storage: Alternative to batteries for grid storage - https://news.ycombinator.com/item?id=25650551 - Jan 2021 (167 comments)

Gravity-Based Energy Storage Begins Trials 2021 - https://news.ycombinator.com/item?id=24337537 - Sept 2020 (2 comments)

To Store the Wind and Sun, Energy Startups Look to Gravity - https://news.ycombinator.com/item?id=22394154 - Feb 2020 (2 comments)

Lifting rocks as a form of long term energy storage - https://news.ycombinator.com/item?id=21736607 - Dec 2019 (1 comment)

Gravity Battery - https://news.ycombinator.com/item?id=6750276 - Nov 2013 (1 comment)

Gravity Battery Concept - https://news.ycombinator.com/item?id=6739349 - Nov 2013 (72 comments)

Others?

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#33

Post by kurthr » Sat, Apr 24, 2021, 7:21 AM UTC

choeger wrote: post #13

Stopped reading at a total cost of more than $300 per MWh for batteries. Quick back-of-the-napkin calculation: Car batteries come in at less than $100/KWh. They're good for at least 1000 cycles at 80% capacity. That gives us at least 0.8MWh for a 100$ investment. It's very, very unlikely that initial construction of the site and operational costs more than triple that price.

What you have described would last for 1000 days used to even out daily (solar) power demand/supply. So for a 25yr capability it would cost 8x more? I would hope not, and I think you could get 3000 cycles by restricting temperature and charge/discharge, but that still requires 2.5-3x higher cost and puts this solution as very competitive with current battery solutions.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#34

Post by cheschire » Sat, Apr 24, 2021, 7:27 AM UTC

choeger wrote: post #13

Stopped reading at a total cost of more than $300 per MWh for batteries. Quick back-of-the-napkin calculation: Car batteries come in at less than $100/KWh. They're good for at least 1000 cycles at 80% capacity. That gives us at least 0.8MWh for a 100$ investment. It's very, very unlikely that initial construction of the site and operational costs more than triple that price.

I wish that cost basis wasn't the only consideration when evaluating energy storage, but we're so accustomed to money being the great equalizer that things without a financial cost associated are often overlooked.

What is the $/MWh cost associated with mining for, recycling, and disposing of battery components? What about the third order effects of centralizing control over the fuel source within only a handful of countries[0]? What's the $/MWh of the political shifts?

I can't safely make assumptions about why you personally stopped reading after cost came up, but it seems to be a common reaction at this point. "Show me the money!" tends to end most conversations about energy these days.

0: https://unctad.org/news/demand-raw-materials-electric-car-ba...

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#35

Post by julienfr112 » Sat, Apr 24, 2021, 7:28 AM UTC

swagasaurus-rex wrote: post #10

arketyp wrote: post #9

Earlier quoted context omitted.

Floating on the ocean catching waves.

Converting H20 -> H2 and storing it in fuel cells

With a heavy water thermonuclear reactor

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#36

Post by tshaddox » Sat, Apr 24, 2021, 7:28 AM UTC

function_seven wrote: post #29

jb775 wrote: post #18

It's crazy how little we understand about gravity if you think about it. It's a perpetual energy source right in front of us, but we never really think about it, and can barely offer a basic explanation as to what powers it. It even impacts time itself[1] for christ sake. I think better understanding gravity is the solution to all human energy needs. (interesting to note I have heard stories of disappeared scientists…

> It's a perpetual energy source right in front of us It's not. Once something has fallen down, it can't fall down again. To draw energy from the gravitational attraction of 2 bodies, you must first separate them. That consumes energy. On second thought, I suppose tidal energy fills the bill. Extracting that energy is really exploiting the Moon's motion, using gravity as the "conduit". Not strictly perpetual, but ess…

Isn’t tidal energy just harnessing some of the existing gravitational potential energy of the Moon-Earth system, which is roughly similar to any system that harnesses energy from a massive object falling due to gravity?

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#37

Post by jb775 » Sat, Apr 24, 2021, 7:28 AM UTC

function_seven wrote: post #29

jb775 wrote: post #18

It's crazy how little we understand about gravity if you think about it. It's a perpetual energy source right in front of us, but we never really think about it, and can barely offer a basic explanation as to what powers it. It even impacts time itself[1] for christ sake. I think better understanding gravity is the solution to all human energy needs. (interesting to note I have heard stories of disappeared scientists…

> It's a perpetual energy source right in front of us It's not. Once something has fallen down, it can't fall down again. To draw energy from the gravitational attraction of 2 bodies, you must first separate them. That consumes energy. On second thought, I suppose tidal energy fills the bill. Extracting that energy is really exploiting the Moon's motion, using gravity as the "conduit". Not strictly perpetual, but ess…

But that "something" keeps being pulled down until it is stopped/blocked by something (e.g. the ground). Gravity is perpetual relative to the source of the gravity. It's just that our surroundings change and give the illusion of gravity changing...i.e. we don't "run low" on gravity

I don't think Maxwell's Demon is 100% solved.

Tidal energy could play into it, some underwater tides deep in the ocean are insanely strong.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#38

Post by exporectomy » Sat, Apr 24, 2021, 7:29 AM UTC

o_p wrote: post #28

what if you lift ion batteries instead of iron

If it's cheaper than batteries, adding batteries will just make it less economical.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#39

Post by jb775 » Sat, Apr 24, 2021, 7:34 AM UTC

nl wrote: post #30

jb775 wrote: post #18

It's crazy how little we understand about gravity if you think about it. It's a perpetual energy source right in front of us, but we never really think about it, and can barely offer a basic explanation as to what powers it. It even impacts time itself[1] for christ sake. I think better understanding gravity is the solution to all human energy needs. (interesting to note I have heard stories of disappeared scientists…

> It's crazy how little we understand about gravity if you think about it. We understand most things about it > It's a perpetual energy source right in front of us, No it's not. It's a good way to store energy but in no way is a source. > and can barely offer a basic explanation as to what powers it It's not something that has power. It's a consequence of entropy. > It even impacts time itself You sound surprised by…

IMO you grossly overestimate the amount humans know about things.

Science is basically a stream of updated realizations that the previous "known" things were actually wrong.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#40

Post by exporectomy » Sat, Apr 24, 2021, 7:36 AM UTC

jb775 wrote: post #18

It's crazy how little we understand about gravity if you think about it. It's a perpetual energy source right in front of us, but we never really think about it, and can barely offer a basic explanation as to what powers it. It even impacts time itself[1] for christ sake. I think better understanding gravity is the solution to all human energy needs. (interesting to note I have heard stories of disappeared scientists…

You shouldn't repeat unsubstantiated rumors like that. Can you even name these disappeared scientists or know anything at all that could be used to verify those stories?