
A new design ship in the Philippines is partly powered by wave energy - awk
https://www.bbc.com/future/article/20200718-the-revolutionary-electric-boat-powered-by-the-ocean
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barbegal
Are there any technical details available for this system? The linked article
doesn't do a good job of explaining how it works or how much impact it will
have.

Assuming the boat can harness 10% of the wave's energy, wave power in the
Philippines is more like 10kW per meter of wave length captured on average so
that equates to ~1kW per metre of wave. Let's assume this boat can capture
roughly 10m of wave then that is an average power generation of ~10kW or ~
10hp. A boat of this size will probably have 500+ hp engines so a boost of
10hp won't have a huge amount of impact.

~~~
Zeebrommer
This is exactly the kind of order-of-magnitude estimation that I was looking
for in the article. Where did you get the wave energy numbers?

~~~
efavdb
Here's a quick estimate: The potential energy of the wave will go like mass x
gravitational acceleration x height. If the depth (front to back) of the wave
is about 1 meter and the height is also about 1 M, then per meter of wave we
get

M g h

g = 10 m / s^2;

M = 1 g / cm^3 = 10^6 g / m^3 = 10^3 kg / m^3;

H = 1 m

MGH ~ 10^4 Joules per meter

If a wave comes every 10 seconds —> 10^3 joules / sec, not far from what this
person quoted. We need to add to this the kinetic energy, which might double
it. Playing with the other parameters we can get close to what the parent
quoted.

~~~
donaltroddyn
Just a note: at sea, when the ratio of wave height to wave length exceeds
0.17, the wave will break, so a 1m by 1m is impossibly steep.

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messo
> The emissions from travel it took to report this story were 0kg CO2. The
> digital emissions from this story are an estimated 1.2g to 3.6g CO2 per page
> view.

Maybe this is what finally could push companies towards making lighter and
more efficient websites? At least an estimate of a webpages watt usage (server
and client side).

~~~
mehrdadn
> The digital emissions from this story are an estimated 1.2g to 3.6g CO2 per
> page view.

Holy cow, that is a _lot_. 1-3 _grams_ of CO2 per single load of a page? Makes
me feel guilty about even clicking the article.

~~~
sephamorr
I'm having a very hard time rationalizing these numbers. Something has to have
some very poor assumptions:

Let's assume each page load is ~1mbit, and it's being served from 1000km away.
1mbit may be low, but most of it will presumably be content delivered by a CDN
which is far closer than 1000km.

The reference design (which I work on) for 400G DWDM systems are ~100W for 2
transceivers + EDFA + switches, for a standard 80km link. Assuming we hop
every 80km (which should be conservative here), we get 3mJ for the energy
through the network. The previous generation is probably 10x worse, so ~30mJ.

Let's add the endpoint too; Wifi router + cable modem (12W or rather 3W
marginal power since it's running anyway/ 200mbit) = 15mJ

And finally for the server. I'd hope the server could do 1k requests per
second, and that should amortize against backends, etc (2k RPS, but frontend +
DB backend server, maybe), maybe 150W for the server, so 150mJ.

This gives us 200mJ for a page load. Using California's current (1:28am)
emissions for power generation of 0.274 mT/MWh (it's 1/3rd of this during the
day), this yields 15ug/request.

Where do the remaining 5 orders of magnitude come from? What am I missing? If
TCO/production energy of the server was included, that couldn't more than
double it (capex in a datacenter < opex, and if 100% of the server cost was
for energy, we could double, but this is wildly conservative)

~~~
barbegal
Here is the methodology [https://www.bbc.com/future/article/20200131-why-and-
how-does...](https://www.bbc.com/future/article/20200131-why-and-how-does-
future-planet-count-carbon)

I think most of it comes from your client device. Your laptop may be using 50W
of power or about 20g of CO2 per hour so reading the article for 6 minutes is
~2g of CO2.

~~~
danielbarla
That makes quite a lot of sense, but it also makes me frown a bit at the
phrasing, which I feel is quite misleading.

"The digital emissions from this story are an estimated 1.2g to 3.6g CO2 per
page view."

Re-reading it, technically they are right, if "view" is taken in a non-
technical fashion. But everyone reading that text would assume if they click
refresh, the emissions are doubled.

Also, I do wonder if they take into account bounced users - I would not be
surprised if most people only spent 5 or so seconds on the page before moving
on.

~~~
proto-n
Also why not add sustinance cost for the human looking at the device then?
Food, water, heating/cooling, clothes, glasses, etc...

Proportionally for 2 minutes of course.

~~~
chriswarbo
Those costs would be the same if the article was read from a newspaper or
magazine, so they can be factored out.

~~~
0xffff2
My desktop is on whether I'm reading the article or not so those costs can be
factored out too.

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jgilias
It looks like there's nothing in the way to put something like one of those
kite-sails meant for cargo ships on a ship like this one to reduce the fuel
needs and hence the carbon footprint even more.

~~~
AtlasBarfed
Add a retractable/foldout solar array for low seas and low wind, add solar
capture to the sail fabric, add windmills for side/tailwind conditions too.

Would probably need to be part of a hybrid powerplant though, but if you could
get even 10-20% efficiency it might pay for itself in shipping where the boats
are in service for a long time usually.

Long range shipping, like air travel, is a major hole in low-carbon strategies
right now. Biodiesel or fuel-from-excess-solar/wind might be the only other
option.

Or thorium powerplants for ships.

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duxup
When I see a wave foil I wonder how that doesn't make more drag than
power...is this similar or something different?

~~~
pjc50
What sort of wave foil do you mean?

It's not clear from this article how the trimaran works, but you can see in
the photos that there is a gap at the top of the outboard hulls. So I suspect
it's the relative motion between the outboard hulls and the inboard one which
is converted to hydraulic power - makes sense, it will be a short movement
with a huge force behind it. That is then fed to a generator, electrical
storage and propulsion unit.

~~~
duxup
Most seem to involve a wing or fin extending out from the hull in some way.

That seems like it would introduce drag and greatly limit speed.

~~~
pjc50
Oh this kind of thing? [https://wavefoil.com/](https://wavefoil.com/)

I'm assuming they've tested it and it's not entirely fraudulen and does in
fact give more speed than drag?

~~~
duxup
I'm not really sure the existence of a thing really indicates efficiency or
usefulness, that's not a high bar.

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axaxs
I've been long enamored with Philippine boat making. The first time I was
asked if I wanted to ride in a canoe, I said no and had horrid flashbacks of
tipping over in dirty ponds in the south USA. Theirs, even homemade ones, have
stabilizers. Such a simple, but brilliant idea.

~~~
ruste
This is likely because stabilizers don't make sense for the usecase of those
in the southern US. Canoes there were typically used navigating between
rivers, creeks, and lakes where the stabilizer would be cumbersome due to
plant life and just size. Ocean going canoes, or canoes on large rivers don't
encounter these problems in the same way making stabilizers worthwhile

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just-ok
It’s honestly a shame that we didn’t keep pursuing sail technology. It’s great
that we’re finally getting somewhere environmentally-friendly with ship tech
nowadays as in the OP, but if we’d put the same amount of effort to innovate
and advance sails like we did steam, I imagine we’d have pretty amazing (and
completely green) methods of transport for all but the heaviest cargo loads
(and even then, just split the load across multiple ships?).

Of course, nowadays the tech is probably so far behind that the cost of the
necessary innovations to “catch up” sails to modern powering methods is
completely prohibitive; I guess the environment will continue to take one for
the team...

~~~
sosborn
I’m genuinely curious, what innovations could there possibly be for sails
beyond increasing surface area or either the sails or the keel?

~~~
satori99
It is worth noting that rigging and sails for lightweight racing hulls has
evolved way beyond anything that has ever been used commercially -- And would
look quite weird (though still recognizable) to a 19th C sailor [0].

Also, the material science involved in creating laminated sailcloth is very
close to state-of-the-art.

Of course, racing yachts go fast because they weigh very little.

Also, Kitesails [1] have been proposed many times over the last few decades,
but I've not heard of anyone using one commercially.

[0]
[https://en.wikipedia.org/wiki/Wingsail](https://en.wikipedia.org/wiki/Wingsail)

[1] [https://cleantechnica.com/2018/09/11/airbus-seawing-kite-
sai...](https://cleantechnica.com/2018/09/11/airbus-seawing-kite-sails-to-cut-
fuel-costs-for-cargo-ships-20/)

~~~
berkes
Skysails[1] sells them commercially. I cannot find how many ships operate
those other than two "prototypes"[2]

[1] [https://www.skysails-group.com/](https://www.skysails-group.com/)

[2]
[https://de.wikipedia.org/wiki/SkySails#Treibstoffeinsparung](https://de.wikipedia.org/wiki/SkySails#Treibstoffeinsparung)

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Theodores
This is a great endeavour but where is the scale model that proved the
concept?

I know scale models don't meet up with realistic waves when on a pond but it
would be nice to see this working. As it is the story is not there yet!

~~~
julosflb
Indeed. A pond will probably not have the right wave. But the concept can be
easily tested with a small scale model in any of the numerous wave tanks
around the world for a tiny fraction of the cost of a full scale prototype...
This kind of wave action scales very well using so called Froud scaling.

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bigbluedots
Aren't all ships partly powered by wave energy if they're facing the right
way?

~~~
Xylakant
No, generally speaking, waves pass underneath a floating object in practically
all circumstances. You may feel like there’s a forward surge when a wave comes
in from behind, but all forward momentum gained while sliding down the wave is
lost once the wave peak has overtaken you and you’re climbing back up the
wave. Basically, waves will induce a circular motion on a floating object.

There’s ways to trick and gain forward speed from waves, by basically picking
a wave that’s high enough and continually sliding down on the front - Surfers
for example. But that only works if your object is substantially smaller than
the wave in question - which is sort of impossible for ships.

~~~
michael1999
Nice explanation.

A boat can start surfing once the waterline fits on one face of a wave, so
<1/2 wavelength. So a 70m tug just needs a 200m long wave. Mind you, those
waves could be 30m tall and breaking over you :-O. So not impossible, but I'm
not eager to try it.

[https://www.passagemaker.com/lifestyle/freaks-of-nature-
rogu...](https://www.passagemaker.com/lifestyle/freaks-of-nature-rogue-waves)

The wave-glider is much more practical.

[https://www.liquid-robotics.com/wave-glider/how-it-
works/](https://www.liquid-robotics.com/wave-glider/how-it-works/)

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aussieguy1234
I've been in one of the traditional Philippines boats on a trip to an island
in not so calm seas, we hired the boat and crew for the day.

It was an interesting but scary experience, probably won't be doing it again.
The island was decent.

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russfink
Novice here - isn't there some static hull shape that would react to waves and
result in motion, much like those plastic widgets that spin only in one
direction?

~~~
onion2k
This design is capturing energy from the vertical vector of wave's motion, so
it works regardless of the direction of the wave or the boat. Capturing the
horizontal part of the wave would be possible, but only if you wanted your
boat to travel in the same direction and at the same speed as the wave. That's
not so useful.

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peteretep
Renewable energy to power boats?! It’ll never catch on

