A new design ship in the Philippines is partly powered by wave energy | Hacker News Reader

A new design ship in the Philippines is partly powered by wave energy

bbc.com

215 pointsawk94 comments

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.

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?

I got them from this map https://commons.m.wikimedia.org/wiki/File:World_wave_energy_...

Probably this[1] is the same boat? [1]: https://en.wikipedia.org/wiki/Hybrid_Trimaran_(Philippine_sh...

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.

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.

From the Wikipedia article Hybrid Trimaran (Philippine ship) [1]:

> Waves gathered from the vessel's outriggers will drive the double action hydraulic pumps which will generate power for the ship.

It sounds like the "outriggers" are the two outer hulls of the trimaran.

[1] https://en.wikipedia.org/wiki/Hybrid_Trimaran_(Philippine_sh...

Found another article with more numbers: "The ship’s “independent multi-engine technology at minimum 3000hp drive shaft sea class” is combined with a wave energy device that’s capable of generating up to 300kw/h of energy, Salvador explains." https://news.mongabay.com/2020/04/a-wave-powered-ferry-aims-...

300kw/h is a nonsensical unit in this case. kw*h would be energy, but kw alone would be the proper unit to compare to the 3000hp drive shaft.

300 kilowatt-hours per hour

> 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).

> 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.

That is not a lot. it's about 4mWh for coal power.

In comparison, leaving a 300W computer setup on for 10 hours each day with coal power is 3KWh or 2.5kg of CO2.

So it takes the computing power equivalent of a 300W PC running for 10 hours to serve a thousand page views? At 50 req/page view, that server is handling ~1.5 requests per second.

That kind of throughput can be handled by a RaspberryPi, so are we seriously wasting 95%+ of the power budget routing packets and idling servers?

A million, not a thousand. Milliwatt-hours to kilowatt-hours.

When I reached the bottom of the page it even loaded an extra article. Now that's a real waste of CO2.

Sending a short email is estimated to release 4g CO2:

https://phys.org/news/2015-11-carbon-footprint-email.html

The average human breathes out 1g of CO2 every minute and a half.

By comparison, average UK cars put out 124.5g for every km driven.

It's not nothing, but it's not a lot either. It probably is worth evaluating the electrical efficiency of the tech industry as a whole, both in terms of highly executed code hotspots and entire pieces of business of questionable utility (ad javascript, cryptocurrency proof-of-waste), but individual web pages are the plastic straws of the industry compared to the giant flare stacks of real problems.

Ads and all the services that make a modern Web page should be included in the estimation.

It's the equivalent of driving 19 metres in an average UK car. That's not far, but that is for a single web page. That seems incredibly high to me.

What is the comparison of the number of cars in the world versus the number of people in the world ?

Estimates of vehicles in use (including commercial) seem to be about 1.2 billion. But the relevant number is surely total miles driven?

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)

Here is the methodology https://www.bbc.com/future/article/20200131-why-and-how-does...

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.

In case someone wants to do the math again :

50W for 1 hour : 50Wh or 0.050kWh

California : 187gCO₂eq/kWh according to https://www.electricitymap.org/zone/US-CAL-CISO

-> 9.35gCO₂eq/h -> 0.16g/min -> 0.935g for 6 minutes

I'd probably use closer to 10W as the device power level (a standard laptop, what I'm using right now), so the number for me would get close to 0.2g, but your point stands; the article is answering a different question than I was assuming, but regardless it seems that the majority of the energy is clearly the local device.

Isn't a modern laptop mostly idle after loading the page (< 5 seconds) ?

There would be a peak for the first seconds, then less than 10W for the rest of the reading time ?

Definitely the peak would be higher. My laptop has a ~60Wh battery and gets ~6hours of battery life, so I was just assuming 10W average for web browsing.

Thanks for the figures. I've bought an ARM PC in part for lowering its footprint.

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.

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.

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

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

Surely "view" should also include the human doing the viewing? :P

According to https://news.ycombinator.com/item?id=24068986, that's 1g every 90s, so 4g CO2 for 6 minutes reading time.

Rest assured that you can make the numbers even worse by using a VPN thus requiring even more intermediate servers and cryptographic computations.

But before admonishing users please consider defending Net Neutrality and copyright reforms so that theses workaround become useless (for general usage). And while you are at it don't refrain from taxing ad-networks that use bandwidth and cpu cycle with over-engineered adware!

But nah, better stick to boomers worldviews, Governments and Big Corp can't do nothing for the planet because people are so dumb ¯\_(ツ)_/¯

How is this comment admonishing users? It looks like an attempt to put mathematical justification to a claim.

The comment is not admonishing anyone, it's about the underlying narrative the comment is addressing.

Sorry my ironic and rhetorical intentions might not have been clear enough, English is not my mother tongue so I might been confusing here.

Basically my point is that heavy calculation about "X is emitting Y shame on you people" is too often used as decoy so you never actually audit Z.

It's the bbc - accuracy is the very least of their concerns. They're much more focused on harassing pensioners for their state sponsored extortion racket money.

I'm not sure that's relevant to this discussion.

The government continues to reduce the amount of money they send to the BBC, which continues to produce world-class television and is struggling to find the money to do so.

They've decided that they will no longer offer the complimentary license to the elderly.

None of that should have any bearing on the accuracy of their environmental reporting.

Just watching a movie about CO2 emissions is order of magnitudes above.

I recently saw another site that tries to offset its carbon footprint: https://mynoise.net/carbonFootprintCompensation.php

I hope this becomes more prevalent at least for paid services.

Not the whole story. The link provides more details (https://www.bbc.com/future/article/20200131-why-and-how-does...)

It involves counting carbon from journalists' travel etc. So a full tally (which is good but isn't just about literal pages loaded)

I also wonder how much JS + adverts have to offer as part of that carbon load.

We need an open source model for estimating the CO2 emissions of a server, of the network (including CDNs, etc.), of a device.

I was also disappointed with the amount of text compared to the amount of information in the article.

It seemed like every paragraph started with for sure you have been in the waves so you know they are waves

Agreed, far too much waffle. The first three paragraphs don't even mention the new ship design.

Why on earth would it finally push companies to do anything? Where is the profit motive in this?

I am not against lighter websites. But it's not gonna happen unless we start pricing carbon.

I remember writing a paper in college about what the environmental impact of a web page was. One of the biggest energy savings Identified by far was changing the color of your website to use dark backgrounds.

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.

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.

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

I assume this works similar in premise to how someone can generate forward momentum by pumping a hydrofoil surfboard like this https://youtu.be/3Ksamgpu2S0

But it looks like this boat isn't using a foil, but rather hydraulic pump based electrical generators inside the boat. The article is short on details on how the design works. They do link to two other foil based propulsion boats though:

https://www.popsci.com/gear-gadgets/article/2008-02/wave-run...

https://newatlas.com/autonaut-autonomous-unmanned-surface-ve...

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.

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.

Oh this kind of thing? 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?

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

Hydrofoils have a very high lift drag ratio. You also have to remember the wetted area of the hull produces significant drag too. Lifting most or all of the hull out out of the water can enable dramatically higher speeds, at the cost of stability and complexity. The biggest America's Cup catamarans were roughly the scale of a 7 story apartment building, but were capable of lifting their entire mass on a foil the size of an ironing board. Because of the density of water, foils can generate a lot of force as lift.

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.

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

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...

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

I’m no expert, but it’s possible that advances in material science, our understanding of wind & ocean currents, GPS, etc. over the last, what, 150 years? all could massively improve efficiency.

As far as I know, humanity was still improving sailing tech till the steam engine dominated it. I guess my point is that it’s impossible to tell where we could’ve been now without actually having those years of iteration & innovation; the steam engine quickly and abruptly stymied all developments on that front.

I can't imagine there would be that many.

Sails just don't provide all that much motive force, and they're far too unreliable (wind dies down, it doesn't matter how much sail you have.)

Maybe the GP was thinking more along the lines of general 'green' tech -- wind turbines, solar panels, etc? It would certainly be cool to see more of those to supplement existing propulsion systems on ships, and that would help reduce the amount of fuel burned for shipping, which uses some of the dirtiest fractions of petroleum.

Combining technologies would absolutely be a great way to pivot, as the article shows. Maybe it’s a dumb question, but why don’t we have sails on modern ships as a supplement?

I just lament that we basically completely abandoned such a great mechanism (sails) so haphazardly just because coal was cheap & reliable; now the environment pays the price.

We use the form factor quite differently. A game and watch is about the size of a cell phone these days.

Sails take quite a bit of space to store, they aren't exactly the lightest thing, and you need training and coordination of the sailors to deal with them. They also probably just dont provide enough benefit to offset the costs -- as I said before, sails don't actually provide that much force.

There are a lot of smaller boats that have both sail and mechanical engines, but that only works because they're small enough that the sails can provide a significant amount of force. And if you look at the transition period between the Age of Sail and Age of Steam, there were a lot of boats and ships that had both sail and steam engines. The sails were mainly relegated to backup, or to help out the steam engines, but these hybrids existed.

Low tech magazine has some practical examples of ships that operate sails in addition to fuel to lower fuel-usage: https://www.lowtechmagazine.com/2007/09/sailing-ship-re.html

At 10 mph wind, sails generate about 0.256 pounds of force per square foot (according to random website found via google). Therefore your several ton cargo ship gets next to nothing from sails.

We do. They just don't look like sails. This is a Maersk ship.

https://en.wikipedia.org/wiki/Rotor_ship#/media/File:Norsepo...

I just looked into the economics of rotor sails.

On average, they save $400/day ($146,000/year) in fuel costs (2017) or about ~10% of fuel consumption. In real terms, it's not much.

They cost about €1-2 mil ($1.1-2.3). Under the most ideal circumstances, that is a ~8 year payback, which is fairly long.

In order for the economics to work out, oil prices need to be higher and externalities (CO2 emissions) need to be included in the price.

Only thing I could think of would be a hybrid boat...sail + solar powered / wind powered electric motor?

They don't work like a traditional sail but "rotor sails" are a fairly recent innovation and seem interesting: https://en.wikipedia.org/wiki/Rotor_ship

I've seen articles here and there about adding them to tankers to increase fuel efficiency.

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

[1] https://cleantechnica.com/2018/09/11/airbus-seawing-kite-sai...

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

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

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

Off the top of my head:

- Motorised rotation of the sails to capture the wind.

- Automated tacking.

As someone who was a racing dingy sailor in his youth, the answer is a gob smacklying lot of improvements have occurred in my lifetime, mostly this century.

Have a look at the America's cup races. Eg: https://www.youtube.com/watch?v=Y325JWyRslE

The first thing that hits you is the hull isn't in the water. The next thing is the sail boats in a modest breeze are giving the powered boats a run for their money speed wise. One thing that is not so obvious is the sails are now more aerofoils.

Back in the day, boats that had no hulls were a mad mans dream. Now we call them kite surfers. Some exotic ones have keel hanging from a bit of rope.

I think you're vastly underestimating how slow it is to ship things by sail. Take a look at some of the routes boats had to take to avoid the doldrums and find favorable winds: https://en.wikipedia.org/wiki/Winds_in_the_Age_of_Sail. Having to sail 2/3 of the way to America just to stay in good winds added 3 weeks to a month to every trip out of Spain or Portugal.

Take a look at the clipper route https://en.wikipedia.org/wiki/Clipper_route. To ship goods across the world by sail in any reasonable amount of time, you have to sail way down in the southern ocean, where the winds and seas are incredibly rough and dangerous, and many many people have died horribly. https://en.wikipedia.org/wiki/Roaring_Forties.

We stopped using sails, because people were tired of sailors taking one for the team.

You are correct for that time period and technology. Linen sails on square rigged vessels required directional winds towards your destination, as they were only efficient for downwind sailing.

Things have greatly improved with the wide adoption of the Bermuda Rig allowing you to efficiently set a course on all points of sail; https://en.wikipedia.org/wiki/Bermuda_rig

There's many challenges for sailing commercial freight but I don't think this would be as much of an issue these days.

Also note that many ships don't require speed.

Yes, your avocado's have to be delivered very time-sensitive. But coal, oil, soy and most other bulk not so much.

In fact, due to price-fluctuations, ships delivering bulk goods sometimes deliberately slow down their route (but I cannot find the incident where and when this was reported anymore)

Edit: three guys I know, operate a sail-powered cargo service [1]. Time is a factor, not because clients require speedy delivery, but because paying three sailors for 2 weeks on-board is more expensive than 3 days. They deliver e.g. chocolate from the west-indies to Amsterdam with their boat.

[1] https://fairtransport.eu/nl/tres-hombres/

> It’s honestly a shame that we didn’t keep pursuing sail technology.

We did, modern sail boats are much faster than they used to be and can almost sail against the wind (~30° from the wind direction). Fastest sail boats can cross the Atlantic in few days now. (speed record: 3days15h [1])

https://en.wikipedia.org/wiki/Transatlantic_sailing_record

Isn't it purely for sport though ?

> It’s honestly a shame that we didn’t keep pursuing sail technology ...

You mean something like this? https://www.top-yachtdesign.com/oceanwings-by-vplp/

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!

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.

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

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.

Thank you for such a thoughtful response.

Second order wave effects can cause drifting also.

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...

The wave-glider is much more practical.

https://www.liquid-robotics.com/wave-glider/how-it-works/

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.

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?

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.

surfboard shape?

You can capture wave motion in all directions with a pendulum based design like this:

https://www.witt-energy.com/howitworks.html

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

Reply on news.ycombinator.com