
Cheaper Battery Is Unveiled as a Step to a Carbon-Free Grid - prostoalex
https://www.nytimes.com/2018/09/26/business/energy-environment/zinc-battery-solar-power.html
======
jpm_sd
Wikipedia says round trip efficiency on rechargeable zinc-air cells is very
low (~50%). Doesn't sound too promising for grid scale storage.

[https://en.wikipedia.org/wiki/Zinc%E2%80%93air_battery#Secon...](https://en.wikipedia.org/wiki/Zinc%E2%80%93air_battery#Secondary_\(rechargeable\))

~~~
nielsbot
Does that matter if there is surplus power during charging times?

~~~
greglindahl
It does affect the economics. A lot of pumped water storage facilities only
have a 50% efficiency, and they make sense from an economic standpoint.

------
olliej
I hate doing this kind of comment, but given the unending stream of "this
battery solves everything" articles, so does this article provide actual
numbers, compared to batteries in production, or development batteries at
similar levels of development?

Or more specifically, what are the answers to these questions:

1\. What is the charge/discharge efficiency? This seems to be something lots
of the "next generation batteries" in articles are bad at (compared to current
commercial batteries)

2\. What is the cycle lifetime?

3\. What is the power density?

For 2 and 3 there was an article on HN last week I think that was using a
gravity potential "battery" that was carbon neutral (and based on super simple
physics) simply by using an electric motor to lift weight, and then discharge
by doing the reverse.

[edit: Using the power of wikipedia it seems like power density is high, but
it also says they're not rechargeable. But also that they are. So can someone
who actually knows the chemistry of batteries give a summary?]

~~~
solarkraft
Thanks for more eloquently saying what I think every time I see a "battery
breakthrough"-post. Virtually none of them are actually viable.

------
woodandsteel
So what is the technology here? The wikipedia article on zinc-air batteries
says a rechargable one would have some great advantages, but also they have
some major problems, like degrading over time and the number of recharge
cycles.

That the company has been selling such batteries for a number of years and now
is announcing it is going to go big time would seem to indicate it has figured
out how to solve these problems, but how does it do it? I looked at the
company's web site and it doesn't give any specifics. Though I did read
somewhere that it has been granted over a hundred patents, so maybe they give
some idea of what they are doing.

------
boyter
Bring it to Australia. Solar is growing at a massive rate, gas is expensive,
electricity is expensive, and anyone with solar will have the ability and be
prepared to spend to get a decent battery.

Assuming this does hit the magical $3000 for 7 kWh of storage installed price
point I can see it being installed all over. At that point its not a 10+ year
proposition to get your money back but more like 5. Heck I would like to have
one as my solar system currently exports 2/3's of the power it produces and I
would love to have a battery system.

~~~
reitzensteinm
Right now they're basically a hack to achieve net metering, which means that
the grid maintenance and capital costs of the grid's power production will
fall disproportionately on users not able to afford the systems.

There'll eventually be a correction as storage ramps up (and this makes the
payback calculations unreliable). Either connection fees will make up a
significantly higher percentage of a bill, or owners of the systems will need
to pay for power like commercial properties do with dynamic pricing.

~~~
coding123
I think he's talking about OFF grid.

------
agumonkey
[https://www.youtube.com/watch?v=OcGWbt1mcrc](https://www.youtube.com/watch?v=OcGWbt1mcrc)

------
DubiousPusher
I know HN doesn't react well to soley critical comments but does anyone else
get a Pons and Fleischmann vibe outta this article?

~~~
greglindahl
Well, the article quotes an expert who says LiIon costs "$300 to $400 a KWh",
while mentioning that Tesla expects to cross the $100 threshold this year. And
it doesn't say anything about how many charge cycles zinc-air can do, or how
efficient it is at round-tripping electricity.

So I'd mostly get a "terrible reporting" vibe from the article. Of course the
company will say great things about its very promising technology. It's up to
the reporter to not publish the press release.

------
Animats
They claim about 100 installations, but aren't selling any batteries as
product. So it works, but is it cost effective?

------
skc
No talk about battery lifetime? How many discharge cycles are we talking here?

------
emnipetro
At this level, you may be damaging your battery if you regularly run it dry.
Lithium batteries can actually die permanently if drained below a certain
point.
[https://www.hptechnicalsupportphonenumbersusa.com/](https://www.hptechnicalsupportphonenumbersusa.com/)

