Are Renewable Powered Ships Possible?

this video was made possible by curiosity stream sign up for the nebula bundle deal for just 1479 at curiositystream.com forward slash real engineering to get access to our nine part logistics of d-day series the lion's share of attention in our quest to neutralize carbon emissions in the transport industry has always been on road transport it's technology we interact with every day it's visceral the smell sound and sight of the internal combustion engine is near inescapable but if we actually take the time to examine the world's carbon emissions we start to see some less obvious polluters that don't get as much mainstream attention yes road transport accounts for around 12 of our total greenhouse gas emissions and we have the technology to reduce that to zero but what about the other 88 percent there are many industries around the world working to neutralize their carbon footprint and each is coming up with ingenious and novel technologies to get them closer to that target one of those industries the shipping industry is responsible for around two percent of the world's emissions the vast majority of this is created by container ships which carry 80 of the world's trade astoundingly there aren't millions of cargo ships hauling our commodities around the world mursk the world's largest shipping company with 17.6 percent of the world's market share of container transport only has 786 ships 786 gigantic ships these ships typically last 20 to 30 years so it's important that we are prepared to convert these ships to carbon neutral technology when their time comes the largest ship in the maersk fleet the triple e is the same length as the empire state building the scale of these ships is mind blowing a single triple e is capable of hauling over 20 000 teu which means it can carry 20 000 standard 20-foot containers to put that into more human terms a single 20 foot container can hold about 6 000 shoe boxes so a single triple e shipment could deliver over 123 million pairs of shoes enough to fit nearly every single person in japan that's insane it's easy to see these ships as gigantic pollution machines each one of these ships has an astounding impact on global emissions maersk as a whole released over 36.5 million metric tons of carbon dioxide in 2019 roughly equivalent to a small country's emissions like ireland but to give credit where credit is due cargo ships are astoundingly efficient much more efficient than any other form of transport this figure was closer to six grams in 2007 but maersk didn't invent some revolutionary technology to achieve this they just slow down fuel consumption of these ships is primarily a function of their size weight and speed this graph shows the relative fuel consumption per day at different speeds and cargo capacities the fuel consumption rises exponentially with each knot of speed added and the heavier the ship the more pronounced that fuel increase is an 8 000 teu container ship traveling at 24 knots would be expected to burn 225 tons of fuel per day but a reduction in speed of just 12.5 to 21 knots would result in a 33 decline in fuel consumption to 150 tons per day the practice of lowering speeds began in 2007 not because of climate change concerns but as a result of rising fuel prices and then in 2008 the practice was fortified by the arrival of the financial crisis placing financial strain on the world economy to survive and lower costs shipping companies looked towards lower fuel consumption and the trend continues today as climate change has come into focus that 42 reduction in emissions is great but getting to 60 by 2030 and 100 by 2050 as maersk aims to do won't be easy slowing down a ship to reduce fuel consumption is a game of diminishing returns below 12 to 15 knots and it just doesn't make sense and to achieve 100 with this method we would just need to turn off our engines a good way to collapse the world's economy so what's the plan to get to 100 percent [Music] something interesting happened when these ships started to slow down their carefully shaped hulls stopped working as designed the hulls of huge ships like this are shaped very carefully to minimize drag but at a particular operating speed lowering the speed of the ships messed with the fluid dynamics and prevented some drag reducing designs from working properly the bulbous bow is a particularly important efficiency device for large ships capable of reducing drag by up to 15 they are by no means a new technology the first ones were fitted to ships like the uss delaware all the way back in 1910 and they work by producing a secondary bow wave which acts through destructive interference to negate the primary wave created by the whole of the ship in simple terms this technology reduces the energy that is being lost to wave creation and also reduces frictional drag as the contact area the ship has with the water is reduced the range of operating speeds for a typical ship in 2007 was pretty narrow today the speeds are not only lower but far more variable bows that were designed for this speed simply won't work as desired at this speed so as part of maersk's fuel saving efforts they began retrofitting their bulbous bows for ones better suited for the new lower operating speeds in 2012 getting an industry like this to clean up their act starts by increasing efficiencies with a machine this large efficiency has to be our primary focus in lowering emissions it's low hanging fruit that can as we have seen result in millions of tons of fuel being saved there is a huge number of technologies being developed with this goal in mind one particularly interesting shift we are seeing in the industry is towards a return of wind power to offer additional thrust to these massive ships a centuries-old technology that once powered shipping empires like the dutch west india company it's difficult to integrate wind power into modern ships shipping companies won't incorporate them if they take up too much space which could be used for cargo and designing them in a manner that allows for a timely return on investment is difficult one particularly interesting form of wind power which is currently being tested is the flatner rotor these rotors use the magnus effect to generate thrust which is the force experienced by a rotating object as a result of the deflected airflow around it when presented with a crosswind these rotors can provide a good deal of thrust for very little energy input modern composite materials have allowed the rotors to be much lighter and thus take less power to spin according to norse power their largest rotors can provide up to three megawatts of forward thrust for an input of just 90 kilowatts of electricity critically they are simple in construction minimizing costs they take up a minimal space on the deck minimizing loss of revenue can be easily retrofitted to many different types of ships and the rotors are controlled by a computer requiring little to no input from the ship's crew these rotors are currently being tested on a maersk tanker and between september 2018 and september 2019 saved 8.2 percent of their fuel if that is repeatable i can't imagine it will be long before we see these devices being fitted to more ships on routes with favorable prevailing winds of course wind isn't going to power these ships by itself we can only get fuel consumption so low and this is where the shipping industry faces its biggest challenge fuel traditionally the shipping industry has used this horrible pollutive heavy sludge like fuel literally bottom of the barrel quality fuel cheap but incredibly dirty releasing heavily polluting sulfur and nitrous oxides into the air the international maritime organization mandated that these emissions need to be reduced and the shipping industry has primarily responded by turning to low sulfur heavy fuel oil fitting scrubber systems to remove the pollutants from the exhaust while others are turning to liquefied natural gas the largest liquefied natural gas-powered ship launched just two months ago which will all but eliminate many of the problems associated with heavy fuel oils and result in about 20 percent less carbon emissions but they are leaking a large amount of methane into the atmosphere a much more potent greenhouse gas at the end of the day this fuel is still a fossil fuel we could switch to biofuels like biogas or biodiesel these are both fuels that are derived using renewable methods of converting biomass into fuel but their ability to eliminate carbon emissions are debatable some methods help reduce the net carbon dioxide output and others are worse for the environment than fossil fuels biofuels like biodiesel unless carefully regulated are completely pointless and could just encourage the conversion of even more woodland areas into farmland to grow soya beans while barely reducing our carbon emissions i'm not convinced biofuels are the answer but i need to look into the subject in more detail to have a more solid opinion on the topic hydrogen is also an option but comes with the usual disadvantages primarily that it is currently very expensive but that hasn't stopped countries like norway and japan from placing their bets in hydrogen for industries like this the shipping industry much like the long-haul trucking industry can take advantage of the hub to hub nature of the cargo hauling industry and build out critical infrastructure along single heavy use routes first japan is one of the primary refuelling stops for the high traffic trans-pacific route connecting the two largest economies in the world china and the united states this route as a result of its length poses some interesting logistic challenges in a transition to hydrogen because while hydrogen has a high gravimetric energy density its volumetric energy density is quite low meaning ships would need to sacrifice some cargo space for fuel storage one study found that about 43 of voyages on the trans-pacific route could be completed without replacing cargo space with fuel storage or making an additional refueling stop they also found that if two percent of the cargo space was replaced with fuel storage 86 of voyages could be made as normal and 5 would allow 99 of voyages to continue as normal alternatively 99 of trips could be made by making one extra refueling stop where that fueling stop can be for a roost this long poses more problems a large detour to refueling stations in alaska would cut into profits perhaps if demand allows it floating refueling stations with their own hydrogen generation powered by offshore wind could service routes like this and allow for the shortest route between china and the usa to continue being used thankfully the shipping industry is already pretty efficient but there is always room to improve this will take investment and will cut into the shipping industry's profits as fuel prices rise but these are necessary moves to not only reduce but eliminate our carbon emissions as we saw the only reason these shipping companies began to move away from heavy fuel is because the international maritime organization mandated it we need to continue putting pressure on companies to not only clean up their technology but be ready for the next step these are big machines that will be sailing our oceans for decades making the wrong move now and betting on a fuel that ultimately isn't better for the environment and isn't scalable is a problem we will have to live with for decades we need to be future focused and make the right decisions today the shipping industry is the backbone of our modern world shipping products from all over the world from food to fuel the modern economy would simply grind to a halt without this service the liberty ships of world war ii are arguably the most influential technology developed during the war cheap and quick to build they allowed the united states to act as the manufacturing hub for the allies on all fronts transporting thousands of tanks men fuel and supplies across the atlantic and pacific oceans in our nine-part series available exclusively to nebula we explore how logistics like this shaped one of the most pivotal battles of world war ii d-day in this two and a half hour long series we explored the unique ships the allies used to get ashore and the secret floating harbours they built and towed across the english channel why normandy was chosen and how they broke through the defenses to get their men ashore how engineers rushed from the beaches to build airfields and fuel pipelines and repair the railways in our final episode released this month we explored how the allies managed to supply the front line as it marched closer and closer to germany this is just the first series we plan to make for nebula and season two is already in the works where we will be exploring the battle of britain in the same nerdy detail the best way to watch this series and ensure that future projects like this can be funded is by signing up for the curiosity stream and nebula bundle deal here you will get access to both platforms for just 1479 a year a great deal that will get you access to this series add free videos from your favorite youtube creators nebula exclusives and new exclusive podcasts like show makers where sam from wendover productions and i interview some of your favorite youtube creators about their life as youtubers what's insane is that you get all that for free because it's bundled with curiosity stream which has loads of award-winning documentaries itself you

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