AukeHoekstra Profile picture
Oct 16, 2021 8 tweets 3 min read Read on X
I agree there is a place for hydrogen in mobility.
I just think it's probably a very small place.

I think this piece of @Toyota chief scientist Gill Pratt is heavily skewed toward hydrogen in order to make it seem more important. Let me show you.
medium.com/toyotaresearch…
Charging speed is limited by the so called C rate of battery cells.
Simply put: larger vehicles with more cells can stomach bigger chargers.
So big trucks will charge just as fast as small cars.

And of course 90% of charging is done while parked so speed isn't an issue there.
I remember how better place imagined that we would swap batteries to overcome charging time. These days are gone and 60 minutes is simply BS. I think in 2030, new EVs coming out can charge 80% of their range within ten minutes. For something you do occasionally that's a non issue
What also bugs me is that H2 proponents compare the battery weight of an entire lithium battery with the weight of unpackaged hydrogen. But it's the hydrogen tank that dominates the weight, which is one of the reasons fuel cell vehicles are currently not (much) lighter.
Don't get me wrong: if you need to be able to travel very LONG distances without the ability to replenish energy, hydrogen has a clear advantage, esp. liquified. That's why it's great for long distance ships and planes. But required RANGE is much more important than vehicle size.
Also, the size comparison is very deceptive. Batteries can be packaged anywhere you like while lowering center of gravity. And batteries are continuing to get more compact.

Rounded H2 tanks take away more practical space than just their content.

Again a very skewed comparison.
Also, if you have to compress hydrogen you probably won't get 70% efficiency.

More importantly, fuel cells are about 60% efficient. If you also include motor losses you are at 55% or so. So the losses are much bigger.

The 90% of EVs is correct though.
So I agree we should not demonize hydrogen cars. If they give battery electric vehicles competition I'm all for it because both can be very good for the climate and there is a place for both.

But let's not skew the facts to make hydrogen seem more attractive than it is.

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More from @AukeHoekstra

Aug 13
Great to see more and more attention for flexible grid pricing.

We must say goodbye to the "copper plate" that offers free power everywhere and every time. It's hideously expensive and outdated.

What we need is smart flexibility.
🧵
The underlying reason is that the costs of different components of the energy system changed:

Some remained high (e.g. pylons, fossil & nuclear)

Some plummeted (e.g. solar, wind, batteries, EVs & inverters)

Some became possible at all (e.g. measuring & steering in real time)
So now we should make good use of these new, clean, abundant and affordable options, even if it means doing things a bit differently than before.

So what should we do different regarding grid congestion pricing?
Read 20 tweets
Jul 28
Some are angry about the "anti-Christian depiction of the last supper" at the Olympic Opening ceremony. (@elonmusk and @realDonaldTrump among others)

A Dutch art historian explains it's not the last supper but a Dutch painting of the Olympic gods.
And I explain what I loved.
🧵
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Original Dutch thread here. I just translated it.


@WSchoonenberg shows that the "tableau vivant" (living painting) is depicting "The Feast of the Gods" by Jan van Bijlert, from 1635.
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The heathen Gods have gathered on mount Olympus for a feast. Sun god Apollo is recognizable by his halo, Bacchus (Dionysus) by the grapes, Neptune (Poseidon) by his trident, Diana (Artemis) by the moon, Venus (Aphrodite) by Cupid.


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Read 24 tweets
Jul 9
With new batteries solar and wind are not only faster and cleaner, but also cheaper.

I'm estimating:
$0.08/kWh for PV+batteries
$0.07/kWh for wind+batteries

@skorusARK gives a good overview of current wisdom, but strongly declining battery prices change EVERYTHING
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I've recently written about how I was surprised I missed the enormous consequences of price reductions in batteries.

LFP cells are now $50/kWh and last 10 000 cycles.
That's $0.005 per kWh.

Say we double that to pack the cells and you are at $0.01/kWh.aukehoekstra.substack.com/p/batteries-ho…
If you add batteries to solar PV, not all energy has to flow through batteries. But let's keep it at $0.01 and add that to the price of solar. That makes PV (and wind) SUPER cheap!

Batteries must be discounted more quickly you say?
Read 10 tweets
Jun 20
Cheap stationary batteries will pave the way for wind and solar in cheap and resilient energy grids. Unfortunately the @IEA is mispredicting it (again).

Thread based on a free substack article I just wrote.
aukehoekstra.substack.com/p/batteries-li…
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Many of my followers know this picture: it visualizes how the IEA underestimates solar. Now I see basically the same problem in their new battery report.

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The IEAs new battery report gives a lot of great info on batteries but also two predictions taken from their authoritative world energy outlook:
1) STEPS which is basically business as usual
2) NZE (Net Zero Emissions) which is aspirational
iea.org/reports/batter…
Read 11 tweets
Jun 16
Batteries: how cheap can they get?

I used the Sunday afternoot to describe how I think that dirt cheap batteries will completely transform our electricity grid, paving the way for solar and wind and replacing grid reinforcements with grid buffers
aukehoekstra.substack.com/p/batteries-ho…
This is something I'm working on for different government and grid operator projects, but I never realized just how cheap sodium batteries could become and how much of a game changer that will be.

So I used my Sunday evening to write this and would love your feedback!
First I look at the learning curve and then we see it is extremely predictable: every doubling of production has reduced prices by around 25%.

It's even steeper and more predictable than solar panels, the poster child of this type of learning curve.
(More details on substack.) Image
Read 15 tweets
Jun 5
Aaaand we have another winner of the "EVs and renewables can never happen because of material scarcety" sweepstake. I thought @pwrhungry was more serious. Let me explain why this is misleading bollox.
First of all, notice how his argument is mainly that Vaclav Smil says this and HE is an authority.

Why bother to write a substack that basically parrots someone else?

Because you don't really understand it yourself and needed to write another substack maybe?
I'm a bit tired of this because Bryce abuses Smil the same way most people who are against renewables abuse him. They emphasize this is a serious and revered figure that knows numbers. They make it about the messenger, not the argument.
Read 14 tweets

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