
A Solar Power Plant designed to deliver 100% of the electricity after sunset - Osiris30
https://pv-magazine-usa.com/2019/10/08/the-sun-shines-only-at-night/
======
mdorazio
For those not reading the article, it's battery storage. Specifically "Samsung
SDI batteries". This is a great use case to see how well grid-scale battery
storage will perform at the point of power generation in comparison to things
like pumped water or thermal.

~~~
polskibus
How do those batteries fare in terms of capacity loss over time ? My li-ion
rechargeable sanyo eneloops AAA batteries seem useless after a couple of
years.

~~~
imtringued
It depends on the depth of discharge and heat management.

Laptops, phones, etc have a poor lifespan because they are frequently
discharged from 100% to almost 0%. It is better to discharge them from 100% to
50% and then recharge.

Batteries generate heat during charging and smart phones can get hot during
heavy use. Without good enough cooling the lifespan of the battery drops.

~~~
StreamBright
Usually the best case scenario is 80 - 20 as far as I know.

~~~
ohduran
I've heard the opposite! Any piece of information that you can share to back
it up? Highly interested.

~~~
StreamBright
Sorry I have studied this in other language and I not even sure how these
things called in English. There is one graph that I remember called Woehler
curve and there is another one that shows how much is the life expectancy
operating between different charging levels (which I cannot find the name
for).

[https://www.researchgate.net/figure/Woehler-curve-for-
lithiu...](https://www.researchgate.net/figure/Woehler-curve-for-lithium-ion-
battery_fig2_275258416)

Update:

It is called SN curve:

[https://www.researchgate.net/figure/SN-curve-applied-to-
batt...](https://www.researchgate.net/figure/SN-curve-applied-to-battery-
lifetime-estimation-Number-of-cycles-in-function-of-depth-of_fig7_249322820)

It shows a bit different picture for Li-ION that I remembered.

~~~
hakejpc
The reading I did years ago stressed that you should definitely cycle
batteries to as close as Zero as possible, but if you want to do long-term
storage keep them at 40%. Seems like there is a lot of myth around how
batteries work and proper practice. A unified resource on this would be great!

~~~
aeternum
Depends on the battery chemistry. NiCd and NiMh batteries which were very
popular 10+ years ago do have a memory effect:
[https://en.wikipedia.org/wiki/Memory_effect](https://en.wikipedia.org/wiki/Memory_effect)

LiPo batteries do not have a memory effect, and you should avoid deep
discharges.

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Pfhreak
I'm not a huge fan of the format of the article, but I _am_ a huge fan of a
solar plant that has sufficient storage (and mindset) to provide power when
the sun isn't shining. The more like this, the better, imo.

~~~
lazyjones
It might be more robust, cheaper and lighter on resources to just build a
global electricity network, so there's always daylight powering the grid
somewhere. Although for small, remote islands, batteries are probably a
reasonable alternative.

~~~
toast0
The Pacific Ocean is pretty vast. When it's noon in Hawaii, there's not a lot
of land area condusive to solar generation.

A global grid would be an immense coordination problem with tremendous costs.
Some form of storage local to each grid is likely to be more cost effective.
There are so many storage options, something should be appropriate as the need
becomes real: pumped hydro / other mechanical, battery, synthgas (maybe),
heat, pressure.

~~~
lgats
We have gone at most 580km/360mi with an undersea cable 95.8% efficient,
€600m, 700 MW capacity
[https://en.m.wikipedia.org/wiki/NorNed](https://en.m.wikipedia.org/wiki/NorNed)

Repeat that cable 9.6 times over 3,459 miles from London to New York would be
66% efficient and cost €5.8b.

If energy is $0.05/kwh in London and you can sell it around the retail rate of
$0.12/kwh in New York, your cable will make around $20k/hour ($0.028/kwh,after
cable losses). Your cable will pay for itself after 33 years of complete
capacity saturation.

With free energy at one side and retail prices on the other, the payoff time
narrows to less than 8 years.

This calculation leaves out so much but it was a fun thought experiment.

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toomuchtodo
Note that the cost per MWh is less than most fossil generation, and far less
than the cheapest nuclear (per Lazard’s most recent LCOE analysis).

It’s clear that solar and battery storage can now provide affordable base load
power, and can be deployed rapidly (this project is set to turn up in 2022).

[https://www.lazard.com/perspective/levelized-cost-of-
energy-...](https://www.lazard.com/perspective/levelized-cost-of-energy-and-
levelized-cost-of-storage-2018/)

~~~
666lumberjack
LCOE is a poor measure of whether something can deliver baseload power cost
effectively because it assumes all MWh are created equal.

What would make it clear whether solar + battery at this proportion is a
viable source of baseload power is output volatility figures for a few years
of operation (though one year would probably give a reasonable indication).

Tangent: The industry has a metric, availability factor, to describe what
proportion of the time a plant can supply energy - but conventionally it only
considers maintenance-related downtime and ignores periods where no energy is
produced because of lack of 'fuel', giving figures of 99 and 100% availability
for wind and solar respectively. That needs to change if we're going to
measure whether renewables can provide suitable baseload power. The
alternative, capacity factor, doesn't ignore periods of no generation in the
same way, but it penalises dispatchable sources for having excess capacity so
it's not great either.

~~~
adrianN
Most power plants we use today can't deliver baseload cost effectively if you
add in the externalized costs of climate change.

~~~
dsfyu404ed
>Most power plants we use today can't deliver baseload cost effectively if you
add in the externalized costs of climate change.

Like it or not tacking on the cost of climate change to power generation is so
far from current reality that adding that hypothetical constraint is
meaningless. The people making these decisions have real tangible costs that
matter right now that they will prioritize in their comparison.

~~~
nicoburns
I'm not so sure about this. I wouldn't be surprised to see European countries
introducing carbon taxes soon.

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cagenut
Here's the vendor datasheet for the batteries:
[https://www.samsungsdi.com/upload/ess_brochure/201902_Samsun...](https://www.samsungsdi.com/upload/ess_brochure/201902_Samsung%20SDI%20ESS_EN.pdf)

It doesn't say the specific chemistry but it shows a chart estimating 6000
100% charge/discharge cycles at 1C until it hits 80% capacity.

So for this system that'd be 16 years of full cycles till it wore down to
being "only" a 240MWh system.

In reality they'll probably cycle it less aggressively than that (95/5 or
90/10) to meet the expected 25 year lifetime of the overall system.

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Symmetry
I'd just like to point out that there are solar plants that can generate power
after sunset too. Solar thermal plants can store their heated working fluid in
an insulated container and use that to power their heat engines later on.

[https://en.wikipedia.org/wiki/Concentrated_solar_power#CSP_w...](https://en.wikipedia.org/wiki/Concentrated_solar_power#CSP_with_thermal_energy_storage)

~~~
kragen
CSP is no longer cost-competitive with PV for raw energy cost because it
relies on the same steam turbines that coal and nuclear stations use. PV is
now cheaper than those turbines in much of the world—in some cases, so much so
that even with batteries, it can beat CSP.

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hakejpc
Layman Science Wizard recently explained to me that pumping water up into a
storage tower (using solar-based energy) and then using the gravity-drop to
generate electricity again (when the sun is gone) was also very effective. A
natural battery of sorts. No batteries to wear out, neither. Feasible?

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moomin
Just to point out a subtle distinction I hadn't caught reading the headline:
the station is designed to only deliver its power at night. That's the 100% in
the headline. The battery storage apparently lasts 7 hours, so there's still a
good five hours of the average night not served by the plant.

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adrianN
Great. Let's build a million of them.

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davidhyde
> Engie says that the Samsung SDI batteries which it has chosen for the energy
> storage solution will be able to deliver electricity for up to seven hours

For anyone who whats to know what SDI stands for it is "Samsung Display
Interface".

[https://community.cadence.com/cadence_blogs_8/b/breakfast-
by...](https://community.cadence.com/cadence_blogs_8/b/breakfast-
bytes/posts/samsung-battery)

