
Duck Curve - B1FF_PSUVM
https://en.wikipedia.org/wiki/Duck_curve
======
OliverJones
Once smart-grid tech starts to emerge, many possibilities to muffle the
quacking of the duck curve present themselves.

The most obvious, and applicable in any climate and weather, is domestic hot
water heating. Temporarily suspending power to electric hot water heaters at
times of high demand can save tons of short-term load. And, it's potentially
responsive enough to support frequency control ancillary services (the very
expensive task of keeping the power grid running at exactly 60Hz or 50Hz when
power demand is changing fast).

Another is electric vehicle charging time-shifting, either mandatory or
voluntary.

A third, more complex, opportunity is HVAC. If heating / airconditioning
systems can get ahead of their needs during late afternoons, then temporary
power suspension in early evenings is feasible. This kind of application may
be easiest to deploy in commercial locations like big-box stores, office
buildings, and data centers.

A mindset change required is this: demand time-shifting IS energy storage.

A bigger mindset change: grid operators are in the information business,
whether they know it or not. All this proposed timeshifting is based on
information.

~~~
kbutler
Each of those has major problems.

Water heating is usually natural gas.

Electric vehicle charging during the day prevents charging at home. So
employers would need to come on board paying for charging stations with
employee parking. And shopping malls, schools, etc.

Heating is also usually natural gas, and while cooling is almost universally
electric, it doesn't take very long minutes to a very few hours) in hot
weather to consume any reasonable pre-cooling.

~~~
function_seven
I imagine the electric vehicle charging could be time-shifted to overnight.
Between 10pm and 6am

Also, energy for water heaters and home heating vary a bit across the country.
Electricity is more common in some parts than in others. Even in places that
are overwhelmingly gas or propane fueled, the 10% of systems that are
electrically powered represent a small but significant opportunity to time-
shift demand.

A/C is definitely the largest culprit here, though. And precooling does work
if you lower the temperature of the interior thermal mass of the house.

I used to do it when I was subject to random 4-hour A/C shutoffs as part of my
discount plan. If I got the house down to 66˚F before the shutoff occurred,
the house would remain comfortable for a couple hours. I may have used an
overall larger amount of power to do this, but it was the "right" power: drawn
from neighbors' solar rather than generating plants.

~~~
AstralStorm
You could create a heatsink by freezing a mass of water then thawing it. The
problem is space for large amounts of water and the high efficiency cooling
and distribution system needed.

------
boulos
I’m surprised the mitigation discussion didn’t include “more wind generation”.
Especially at the coast [1], you have plenty of wind at and around sunset from
the large temperature differential. The chart is load minus solar/wind, but
the example graph was a low wind day apparently (and IIRC, we are
predominantly solar in California).

But even then, this curve doesn’t seem to apply in California in the summer
when load demand is highest (look at CAISO demand for say July 24). The amount
of built up generation should be looked at in terms of annual peaks and
overall efficiency. July has demand up to 45GW range where renewables are only
currently able to shave off 10 GW of that (but basically all day long). The
forecasted demand for today has a peak of 25 GW.

Is it “just” about how quickly net demand spikes? The grid seems to handle 10+
MW or scheduled maintenance (look at October 1).

[1]
[https://www.windfinder.com/forecast/pacifica_dumps_san_franc...](https://www.windfinder.com/forecast/pacifica_dumps_san_francisco)
(ignore the current high winds, go a few days forward).

~~~
danans
> I’m surprised the mitigation discussion didn’t include “more wind
> generation”. Especially at the coast

This is just my conjecture, but I wouldn't be surprised if the very high cost
of coastal land, and possible objection by nearby homeowners in CA is part of
the reason for lack of wind power on the immediate coast.

If you go just a bit inland, however you'll find the massive new Turtle Island
wind farm near the Sacramento River delta.

~~~
Filligree
Coastal _land_ , yes. It's usually unproblematic to build wind farms offshore,
and they work even better there.

~~~
ZeroGravitas
Offshore wind power started off in areas with shallow seas, it's only now
getting around to floating wind that would suit California.

~~~
dredmorbius
California will have plenty of shallow seas, by and by.

Mostly in places like the Bay counties, Stockton and Sacramento.

------
diafygi
CAISO has a great live dashboard that you can play around with on the actual
real time demand and supply curves. If you switch to previous days, you'll see
the "duck curve" is already here and not just speculation anymore.

[https://www.caiso.com/TodaysOutlook/Pages/default.aspx](https://www.caiso.com/TodaysOutlook/Pages/default.aspx)

The issue nowadays isn't so much the depth of the dip in dispatchable (e.g.
traditional) generation, but the slope of the ramp back up after the sun goes
down (e.g. the "neck" of the duck). Base load natural gas an other fossil
generation have a very difficult time spinning up that quickly (CAISO said it
was ~11GW over 3 hours yesterday).

That's why batteries are such a hot topic in renewables right now. Not so much
for storing power for "a rainy day", but for helping load shift during the day
to prevent such a steep slope in the evenings. Lithium is pretty good at doing
that kind of short, daily-burst storage job.

~~~
tialaramex
Couldn't you do other types of storage rather than batteries? Pumped storage
can do very fast spin-up because gravity doesn't take any time to warm up,
nothing to 1.8GW in a few seconds at Dinorwig (in Wales), if you own half a
dozen of those then 11GW in 3 hours feels like child's play.

Not everywhere has the geography for building power stations inside mountains
(which is the only way to do pumped storage that isn't horribly ugly), but the
US is huge and seems like there are mountains everywhere you look in some
parts, surely some of them are suitable for hiding a pumped storage facility?

~~~
phyzome
Pumped hydro needs a pretty specific geographic profile. It's pretty great
where it works, but good luck finding good candidate spots.

Some people have been working on an approach pulling railcars full of rock up
a slope, which should have more location options, but I don't know how the
math and economics works out.

~~~
fluffything
> Some people have been working on an approach pulling railcars full of rock
> up a slope, which should have more location options, but I don't know how
> the math and economics works out.

Have a link?

~~~
NeedMoreTea
There's a similar approach that seems promising - dropping a huge weight down
disused mine shafts, and winching it back up at times of low demand. It looks
to be a lot simpler than the railway wagon approach.

The UK has _loads_ of potential sites, I imagine the US does too.

A fairly detailed look: [http://euanmearns.com/short-term-energy-storage-with-
gravitr...](http://euanmearns.com/short-term-energy-storage-with-gravitricity-
iron-versus-ion/)

------
z-cam
We think that leveraging electric vehicles as a storage device will help solve
the duck curve problem.

Utilities are reluctant to invest billions of dollars in energy storage to
smooth out their demand curve.

But consumers are already making this investment by switching en masse to EVs.

We're building software that will one day help utilities transact with
individual or fleet vehicle owners to leverage their vehicles as energy
storage.

~~~
Reedx
Or we could just stop kidding ourselves.

As Bill Gates and others who've done the math have repeatedly said[1], there
is no storage solution anywhere on the horizon. Batteries are orders of
magnitude too expensive.

You have to consider the problem holistically. Steel and concrete production.
Places like Tokyo that go days without power. Countries like India that are
not going to pay a premium.

If you're concerned about climate change, please take a serious look at
nuclear energy[2][3][4].

1\. [https://youtu.be/d1EB1zsxW0k?t=520](https://youtu.be/d1EB1zsxW0k?t=520)

2\. [https://www.gatesnotes.com/About-Bill-Gates/Year-in-
Review-2...](https://www.gatesnotes.com/About-Bill-Gates/Year-in-Review-2018)

3\. [https://ourworldindata.org/what-is-the-safest-form-of-
energy](https://ourworldindata.org/what-is-the-safest-form-of-energy)

4\.
[https://www.forbes.com/sites/michaelshellenberger/2019/02/05...](https://www.forbes.com/sites/michaelshellenberger/2019/02/05/if-
saving-the-climate-requires-making-energy-so-expensive-why-is-french-
electricity-so-cheap/)

~~~
yorwba
According to the U.S. Energy Information administration, nuclear is more
expensive than battery storage:
[https://www.eia.gov/outlooks/aeo/assumptions/pdf/table_8.2.p...](https://www.eia.gov/outlooks/aeo/assumptions/pdf/table_8.2.pdf)

~~~
Reedx
Yet in practice let's take a look at France (nuclear) vs Germany (leading
solar/wind):

 _" French electricity costs are just 59% of German electricity prices. As
such, according to the prevailing economic wisdom, French electricity should
be far more carbon intensive than German's. And yet the opposite is the case.
France produces one-tenth the carbon pollution from electricity.

Why? Because France generates 72% of its electricity from nuclear, and just 6%
from solar and wind."_

France is cheaper and produces 2x more electricity from clean sources compared
to Germany, where costs keep going up.

~~~
ZeroGravitas
And yet both France and Germany plan to move to mostly renewable. Which the
French government thinks will save them money. Something that probably
wouldn't have been possible without Germany's far sighted leadership on this
issue.

I wonder how you could attribute the carbon saved by all the people choosing
solar and wind as the current cheapest options to the people who put their
money where their mouth was when that was just a projection.

~~~
thrower123
Right. Far sighted leadership of shutting down perfectly good, clean, nuclear
power plants, and trying to replace them with intermittent renewables. That
need to be backed up by more reliable alternatives, like strip mining old-
growth forests for dirty brown coal to burn in steam generators, or importing
electricity from France's nuke plants.

Just brilliant.

~~~
ZeroGravitas
You're thinking too small.

Climate change and deforestation are global problems, and Germany has helped
fund a global solution.

Solar and wind are growing rapidly, they're currently passing the total yearly
generation of nuclear but with 30% yearly growth will soon be adding the
equivalent of the total nuclear fleet every year.

It is actually brilliant.

If Germany has sacrificed some of their own woodlands to make that happen then
that's just more impressive.

~~~
thrower123
Avoiding nuclear power is just stupid, and shutting down functioning plants is
cutting off your nose to spite your face. If you actually care about net
effects on the environment, anyway.

~~~
onlyrealcuzzo
I don't know, but I suspect the French government isn't shutting down
perfectly good, economical nuclear plants just to spite themselves.

I imagine that the nuclear plants are expensive to maintain since they're
getting old. So rather than maintain them, they're probably going to just shut
them down. And since new ones are so insanely expensive to build (again, don't
know why), it's probably more feasible short term to invest in renewables.

But that's just my suspicion. I know nothing of French politics and very
little about energy generation, but a little about finance, politics, and
human psychology.

I'd love to know what it costs to maintain the nuclear plants they're shutting
down, how much they're spending on renewables, and I'd love to look at it
finacially. It's possible it doesn't make sense, and they just want the "green
jobs". It's possible none of it makes sense! But I suspect there's some sense
in this somewhere.

~~~
thrower123
As far as I know, the French are not shutting down nuclear plants.

The Germans did shut down operating plants, for political reasons, with the
excuse that the capacity would be made up in solar and wind. When that fantasy
failed to materialize, they had to fall back on burning more dirty coal.

Lose-lose.

~~~
imtringued
You're just pulling that out of your ass now. Germany already had enough
renewables to compensate for the loss of the nuclear energy. The problem with
shutting down nuclear instead of coal is that it canceled out the emission
reductions of deploying renewables. The amount of energy being produced by
coal remained unchanged for 5 years and so did the emissions but they never
added more coal capacity.

[https://www.cleanenergywire.org/sites/default/files/styles/g...](https://www.cleanenergywire.org/sites/default/files/styles/gallery_image/public/paragraphs/images/fig2-gross-
power-production-germany-1990-2018-1.png?itok=tUT8go1j)

------
nxpnsv
The Duck picture alone makes this page worth checking out

~~~
saghm
I went into the article based on your recommendation, and I was not
disappointed

------
Tempest1981
With PG&E shutting off power in California, I think we'll see a growth in
battery packs (like Tesla Powerwall) -- at least among the ~1 million impacted
customers.

There is now a much stronger incentive to get off the grid, with the shut-offs
expected to continue for 10 years.

------
carapace
[http://www.geni.org/globalenergy/library/newsletters/1995/bu...](http://www.geni.org/globalenergy/library/newsletters/1995/buckminster-
fuller-on-the-global-energy-grid.shtml#GlobalEnergyGrid)

> "This now feasible, intercontinental network would integrate America, Asia
> and Europe, and integrate the night-and-day, spherically shadow-and-light
> zones of Planet Earth. And this would occasion the 24-hour use of the now
> only fifty per cent of the time used world-around standby generator
> capacity, whose fifty per cent unused capacities heretofore were mandatorily
> required only for peakload servicing of local non-interconnected energy
> users. Such intercontinental network integration would overnight double the
> already-installed and in-use, electric power generating capacity of our
> Planet."

> Telegram to Senator Edmund Muskie, Earth, Inc., 1973, Fuller.

------
dimitar
This applies to Photovoltaics only, not to wind or concentrated solar, and
looks like something that is pretty specific to California's energy mix and
policies.

If we replace fossil fuels during the day and turn on hydro and other during
the night, I still think the duck curve is not an argument against adding much
more PV capacity.

------
k__
Could we use space mirrors to illuminate solar farms at night?

~~~
semiotagonal
Wouldn't it be cheaper just to whip a cable over to Australia?

~~~
lazyguy2
We could bore a series of holes through the center of the planet and then use
gigantic orbital crystals to create a array of lazers to focus the sun's light
through to the dark side of the planet.

~~~
jjoonathan
I'm a fan of using magical heat-producing rocks to boil water and spin
turbines, but admittedly that _has_ fallen a bit out of fashion.

~~~
MiroF
This could be nuclear or coal

~~~
jjoonathan
There's an argument to be had that burning coal doesn't count as magic while
fission does, but in any case, good catch, let me amend that to: magic heat-
producing rocks that _don 't_ fill the atmosphere with dinosaur squeezings.

------
anonu
It is because of effects like the "duck curve" that make me wish I was an
electricity trader. Being able match these patterns and events and correlate
them to different geographies would probably be quite profitable.

I briefly looked into trading on some of the popular ISOs (NYISO for example)
- but it quickly became clear to me that my hobbyist approach to these markets
was not going to cut it as they are way more technical and require a bit more
capital than your typical equity markets.

EDIT: [https://www.nyiso.com/](https://www.nyiso.com/) << if you want to learn
more about the US de-regulated and open electrical grid, this site has 100s of
technical pages and material. They seem to want and encourage people to be
part of the market.

------
phyzome
Sounds like capacitors would help here, even regular ones, since they'd only
need to hold excess solar energy for a few hours in order to smooth out that
evening demand.

~~~
mod
In the graph on the page, the solar output isn't even meeting the current
demand. No need to store it.

~~~
hn_throwaway_99
The point is that, without storage, no matter how much solar you install you
don't lower the required amount of fossil fuel plant capacity at all because
the peak occurs when solar is at 0.

~~~
ZeroGravitas
The yearly peak, in summer, occurs when solar is running.

The daily peak, on spring and autumn days, falls outside the solar peak, but
also well below the yearly peak.

So solar does help displace the least efficient and most expensive part of
your gas fleet.

But it's not the peak that's the point of the duck curve, it's the solar
falling faster than gas can switch on and that difference is very amenable to
being fixed by even a small amount of battery storage.

~~~
cesarb
> it's the solar falling faster than gas can switch on

Is "switch on" really the problem? As Germany showed during the solar eclipse
([https://www.dw.com/en/german-power-net-survives-solar-
eclips...](https://www.dw.com/en/german-power-net-survives-solar-
eclipse/a-18331190)), as long as it's a predictable event, you can have the
necessary generation already "switched on" and running at a low power, and the
limit becomes only how fast you can ramp up their power. Which is still an
issue, but not as much as it would be if they had to turn on all the gas
generators with zero notice.

~~~
ZeroGravitas
Yeah, it's just the ramp up, it's predictable in advance.

Also the worst case scenario is curtailing some solar because you need to
bring the gas plants online a little earlier.

------
ZeroGravitas
The duck curve is a non-problem, just like all the predictions from the same
era that 5, 10, 15, 20, 25% was the absolute limit that renewables could
provide without totally overhauling the grid.

That number has continually risen as grids just did it and blew past the
imagined limits.

California now has a mandate for 100% clean energy which makes "we can't turn
our gas plants on fast enough a few days a year to avoid curtailing some
renewables" seem ridiculously parochial.

On those high renewable, low demand days in the future there will be plenty of
responsive demand to soak it up. Free car charging for anyone plugged into a
socket for example.

------
iddqd
I drew a duck graph on a whiteboard the other day. Wish I had known it had a
name, could’ve gotten an easy chuckle from the room.

------
ssalka
See Also: Bart pattern in crypto trading

~~~
robbya
[https://cryptocurrencyfacts.com/2018/04/16/the-bart-
crypto-p...](https://cryptocurrencyfacts.com/2018/04/16/the-bart-crypto-
pattern/)

------
sandworm101
So there is no wind in california?

------
baybal2
This problem is blown out of proportion.

The energy storage is not a "do or die" issue for the industry by any extent.

Technical solutions for short term energy storage are known, and been used for
decades. Were it economically sound, it would've been adopted already. In
fact, it is being done when the need is genuine, just without much publicity.

People who spin this topic feel to me to be in the business of selling tech
companies.

~~~
acidburnNSA
The problem today is solved, almost universally, with high-carbon fracked
natural gas plants. This is cheap in current markets and incredibly effective
from a technological standpoint. As we recognize climate change as a problem,
this solution loses credibility, but yet, there it is.

I don't think people are recognizing how hard it is to deeply decarbonize with
intermittent energy sources, and so I have to disagree. I think this problem
is too often brushed aside as a non-issue by renewable energy optimists.

~~~
diafygi
Hmmm, so I work in the distributed energy resources sector, and I disagree
that people in this space aren't recognizing how hard it will be to deeply
decarbonize using intermittent generation. You're completely correct that as
we add more and more intermittent generation to the grid, keeping the grid
always online becomes crazy difficult.

However, everyone I know in the space looks at that challenge as opportunity
rather than discouragement. It's not like we're going to hit high penetrations
of intermittent renewables overnight. It's going to be a gradual ramp over
years that allows us to also deploy complimentary systems to deal with the
ever increasing intermittency. Piece-by-piece we will deploy flexibility
technologies (DR, DERMS, storage, etc.) and move to new regulatory incentives
and utility business models (performance-based ratemaking, etc.) that allow us
to reach our 100% goals.

There's a ton of super smart people already working on the intermittency
problem, and entire businesses are being built to solve it (disclosure: many
of them use our platform). So I guess while I agree with your assessment of
the level of difficulty, I don't agree with your level of despair. There's way
too many smart engineers working in the space now for intermittency to be in
impossible problem to solve.

~~~
acidburnNSA
I'm sure people in the space are well aware of intermittency issues. I think
the interested public isn't well aware of it. Many people seem to think
batteries solve the problem, and it's just Big Oil and Big Coal in the way.

I'm not despairing that it can't be done. I just think people who say it's a
solved problem are undercutting the challenge, and hand-waving away serious
problems with the 100% intermittent renewable route while proclaiming
confidently that other massive low-carbon energy sources aren't desired or
needed. Full disclosure: I'm a nuclear proponent.

I know we can decarbonize rapidly; it's been done at scale in small regional
areas many times.

