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Why energy storage sucks

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Re: Why energy storage sucks

#31

Post by msandford »

bloat wrote: post #29
masklinn wrote: post #22

Earlier quoted context omitted.

Pumped hydro is absolutely great, but it's an option for tremendous (grid-level) scales, and requires convenient locations (e.g. a hilltop you can "blow up" with a large stream nearby, or a standard dam with a lake or lake-able location close to its foot). It's way, way beyond the scales the article is talking about (note the picture from a health clinic in Rwanda).

How big of a tank on your roof do you need to replace a box of lead acid batteries?

Is your house 100 feet tall or taller, and I hope your whole house is made out of structural steel.

Re: Why energy storage sucks

#32

Post by jsingleton »

There are broadly two types of energy storage. Grid scale and domestic. This article is about the latter as it focuses on certain batteries. It's actually pretty interesting but the scope is narrow.

Domestic is important as it can leapfrog other tech in places without a reliable grid. Much like mobile phones leapfrogged fixed lines in Africa. There are lots of options for the grid but only batteries really work at a small scale.

For more on this watch this recent video from Al Gore: https://www.ted.com/talks/al_gore_the_case_for_optimism_on_c...

At grid scale you can have exotic types of batteries, pumped storage and other things. For example, there are plans to double Cruachan: http://www.bbc.co.uk/news/business-35666993

Re: Why energy storage sucks

#33

Post by out_of_protocol »

brownbat wrote: post #2

Surprised there's no mention of Vanadium Redox as an alternative that solves several of these problems even better than Lithium Ion. They can be fully cycled over 100,000 times (compare to Li-ion's 400-1200, lead's 500-800) and are expected to last 20 to 30 years. They can stay in a single state for long periods of time without degradation and can be rapidly and efficiently charged or discharged. There's also no fire…

Better flow batteries under development: https://en.wikipedia.org/wiki/Flow_battery Some as good as li-ion, potentially great replacement for the cars

(someone actually built a car powered by flow batteries, take a look: http://www.gizmag.com/900-hp-supercar-flow-battery/31091/)

Re: Why energy storage sucks

#34

Post by mhandley »

bloat wrote: post #29
masklinn wrote: post #22

Earlier quoted context omitted.

Pumped hydro is absolutely great, but it's an option for tremendous (grid-level) scales, and requires convenient locations (e.g. a hilltop you can "blow up" with a large stream nearby, or a standard dam with a lake or lake-able location close to its foot). It's way, way beyond the scales the article is talking about (note the picture from a health clinic in Rwanda).

How big of a tank on your roof do you need to replace a box of lead acid batteries?

A 12V deep-discharge lead-acid battery is typically 120amp-hours. That's 1.4kWh. Suppose you only 50% discharge it for longevity, that's 700Wh. I'll assume your box of batteries has ten of them, so a usable capacity of 7kWh. 1kWh = 3.6MJ, so 7kWh = 25MJ

How high is your roof? Lets say 10 metres. Potential energy U = mgh. (m=mass in kg). h=10, g~=10, so U=100*m.

So, to equal those batteries, assuming 100% efficiency, the mass of water needs to be 250000 kg, or 250 tonnes. Probably going to need to reinforce the loft.

Re: Why energy storage sucks

#35

Post by Cyph0n »

anonymousDan wrote: post #18
Cyph0n wrote: post #16

Earlier quoted context omitted.

I didn't notice anything serious. Perhaps you should try to tone down your "superior grammar" dial?

Nah, he's right it's practically unreadable.

Unreadable? Sorry to tell you this, but your standards are unpractically high. Welcome to the real world, where not everything is how you want it :p

I'm sure that with such an attidtude, you'll be learning a lot from people with different backgrounds and cultures. /s

Re: Why energy storage sucks

#36

Post by Cyph0n »

snorrah wrote: post #19
davedx wrote: post #3

I really want to read this article, but there are too many spelling and grammar mistakes or lack of punctuation. Please consider spellchecking it?

If your English skills are reasonable, it's fairly easy to parse the article and fill in the gaps yourself. Probably easier than a non-native writer wrestling with a spelling or grammar checker when they might not know if the suggestions presented are good or not.

I agree completely. It seems some HN readers think that if they have perfect English (they do not, sadly), everyone else should rise up to their unrealistically high standards. I guess us programmers are a bit more sheltered from the real world. Add to that the primarily US-based audience, and you have what is called a "hivemind".

Re: Why energy storage sucks

#37

Post by aolagers »

paulsutter wrote: post #20

Pumped hydro is much cheaper than batteries per KW (max storage rate) and KWh (storage capacity) is limited only by reservoir size. The roundtrip efficiency is about 80% and it's able to store for months at a time. Heindl Energy in Germany is developing hydraulic storage, which can work even on flat ground (basically, raising a rock formation with pumped water). They've designed capacities up to 120GWh: http://www.he…

Pumped hydro is interesting but the reservoir requirements are huuuge. This post makes a very convincing case that scaling it up is not that simple:

http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor...

There is some discussion about the German rock variation in the comments. The density doesn't seem to help THAT much compared to water only.

Re: Why energy storage sucks

#38

Post by alblue »

Cyph0n wrote: post #35
anonymousDan wrote: post #18

Earlier quoted context omitted.

Nah, he's right it's practically unreadable.

Unreadable? Sorry to tell you this, but your standards are unpractically high. Welcome to the real world, where not everything is how you want it :p I'm sure that with such an attidtude, you'll be learning a lot from people with different backgrounds and cultures. /s

For future reference: unpractically is not a real word. Please consider using real words such as impractical.

Re: Why energy storage sucks

#39

Post by [deleted] »

alblue wrote: post #38
Cyph0n wrote: post #35

Earlier quoted context omitted.

Unreadable? Sorry to tell you this, but your standards are unpractically high. Welcome to the real world, where not everything is how you want it :p I'm sure that with such an attidtude, you'll be learning a lot from people with different backgrounds and cultures. /s

For future reference: unpractically is not a real word. Please consider using real words such as impractical.

[deleted]

Re: Why energy storage sucks

#40

Post by dangravell »

mangecoeur wrote: post #28

Very limited view of energy storage tech frankly. Quick list of things I am aware of (some deployed and some in labs) - Pumped hydro, by far the most widespread - Flywheel storage, used at grid scales for frequency regulation - Thermal storage used in conjunction with solar power using various materials - molten salt, HTF, hot dry rock - Many different battery chemistries: - High temperature batteries (e.g. ZEBRA bat…

Some interesting products utilising PCMs in the domestic hot water markets... Replacing traditional hot water cylinders which suffer from very high heat loss even when insulated.
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