China mulls high-speed train to US
chinadaily.com.cn
chinadaily.com.cn
I guess the value of the article kindly submitted here is as a reminder that many news stories about China seem credible to readers who have never been to China, even if they are incredible to people who have been there. The Chinese saying "百聞不如一見" (hearing of something a hundred times isn't worth seeing it once) may apply here. For a long time, there were submissions here to HN about a guy in China who was going to build a pre-fab high-rise hotel building in just one day. That still hasn't happened. Predictions about the future are fun to think about--that's why I used to read science fiction stories--but we can best size up how a country is doing[1] by looking at current news and sustainable trends. (In the case of China, it is important to look at reporting from publications other than official publications of the one-party-dictatorship government of the country as a reality check.)
Good luck with that high-speed train from China to America. I wonder if I will be able to ride that or ride a space elevator[2] first.
[1] http://www.todayonline.com/business/chinas-property-bubble-h...
http://blogs.wsj.com/chinarealtime/2014/05/05/chinas-propert...
It has been running since 2006.
The rail line in the article makes no sense. It would be incredibly expensive (particularly the tunnel), there's no strategic reason for it, people would rather fly at that distance, and freight is cheaper to ship by sea.
https://en.wikipedia.org/wiki/Broad_Sustainable_Building
He's now trying to build the world's tallest building with the same method, and while construction hasn't started, it's a lot less vaporware than this high-speed rail project:
Aviation will almost certainly become too expensive to be viable in the not terribly distant future. The US saw peak avaiation fuel in 1999, from the FAA's own 2000 projections and actual usage[1]. Steve Kopits has noted that peak departures (US) occured in 2005[2]. Total passengers miles remain up, but that's due to more efficient aircraft with higher load factors (a greater percentage of seats filled).
Even if synthetic fuels (possible) or biofuels (exceptionally unlikely) are possible for aviation, fuel costs (already a major component of airfare) will almost certainly rise. The US Naval Research Lab thinks it might hit $3-6/gallon for production costs. I suspect that's optimistic and note that crude oil represents 72% of the final cost of refined gasoline, so this could translate to $4.17 - $8.33/gallon retail (present JetA price is $5.74 in the US NorthEast: http://100ll.com/). Canola biodiesel has a production cost of around $1000/bbl, or (with estimated refining costs) about $33/gallon.
A 3000 mile flight in a Boeing 777 at full capacity gets about 60 passenger miles/gallon, which equals 50 gallons of fuel per passenger. That's $287 presently, $415 at $8.33/gal, or $1650 at $33/gal, just for comparison, in fuel costs alone.
So, yes, exploring ground transit alternatives might make sense.
________________________________
1. http://www.faa.gov/data_research/aviation/aerospace_forecast...
2. http://energypolicy.columbia.edu/sites/default/files/energy/... p. 37., citing US DoT.
You are assuming jet fuel as it is today will be the only way to fly planes tomorrow? What about improved batteries or even fuel cells?
Even those trains will need power, and creating a lined system for that distance without many local power plants to drive it would be a logistical nightmare.
A Boeing 777-300ER carries 304,000lbs of fuel fully loaded. This contains just under 6 terajoules of energy.
The battery pack of a Tesla Model S is about 300 megajoules.
So you,d need 19,700 Tesla battery packs to power your 777-equivilant jetliner. Problem is they weight over 15 millions pounds.
So no, there is no magic bullet in aviation.
People have often claimed that we will exhaust our resources at some future point, but these predictions have always excluded technology advancements that have always come before any resource crisis has occurred.
The best possible battery designs actually do approach the energy storage density of liquid hydrocarbons, nearly, and theoretically (metal-air batteries, specifically lithium-air).
The best currently practical battery designs are at least an order of magnitude less dense.
And as I note above and in my longer piece (linked above), the additional engineering constraints for electrically powered aircraft argue against their feasibility.
Synthetic fuels strike me as much, much, much more viable, though even there the economics of flight will change markedly. Probably acceptable for the military and VIPs, not so much for everyone else.
Shift from turbofan aircraft operating at Mach 0.9 to ducted-fan turboprops at perhaps mach 0.7 would reduce fuel consumed per-mile quite a bit.
Ducted fans and propjets have their own issues (primarily weird/obnoxious noise characteristics) but if fuel costs spike I suspect that will be dealt with.
I'm not an aviation engineer. I'm aware that electrically powered turbines (ducted fans) are possible, and that they're used on some RC-controlled model aircraft (as well as actual fuel-fired gas turbines). My understanding is that they have much lower efficiency than props.
Given the already unfavorable energy, weight, and storage characteristics of aircraft, I'd think that efficiency would win over speed in most cases.
I may not be fair because it may not have been what you meant, but I need to address this.
It wouldn't be like a nuclear bomb going off. It wouldn't even be like a nuclear power station going into meltdown. The US purposefully made a nuclear rocket go through a worst-case scenario in the 60s and it didn't permanently irradiate the desert or anything.[1] It would kill people on the ground and you would need professional clean up, but that's also the case with normal plane crashes.
http://en.wikipedia.org/wiki/Nuclear_thermal_rocket#Kiwi-TNT
Add to this the tendency for aircraft to crash in two general locations: at or near airports, which is to say, in the middle of a bunch of people and/or other stuff generally considered valuable and whose preferred state is non-irradiated, or way the hell in the middle of nowhere, which is inconvenient for all and sundry to access, including radioactive contamination mop-up mod squads.
Then there's the general halt-and-catch-fire problem which further compounds the general tears and frustrations concerned with dumping fissibles and decay products all over creation.
Normal plane crashes tend to kill the people who are loitering around the crash site while it's busy being a crash site. They don't go for the slow lingering kill, or just the damned uncertainty that accompanies known or, well, we're not sure, maybe, maybe not, radiation exposures. The acute nature of most chemical fuel incidents means that the risks, while not insignificant, tend to be effectively mitigated often in a matter of minutes to hours. Not years or centuries.
Garrett Hardin (of "Tragedy of the Commons" fame) was one of the critics of SST, and I believe it was that which prompted him to note, effectively, that humans didn't simply have to follow the technological imperative: that because we could do something we had to do it.
I'm surprised that, post-Concorde the claim is that Concorde was actually making BA a profit. It had always been presented as a commercial failure to my recollection:
http://www.concordesst.com/retire/faq_r.html
On average Concorde made and operating profit of £30-50 Million a year for British Airways in the boom years where many passengers were travelling first class. British Airways reportedly received £1.75 Billion in revenue for Concorde services against an operating cost of around £1 Billion. Air France made a much smaller profit.
Thinking out loud, you might build it with minimal fuel on board at all, doing a sled launch[1] or having it run its own engines off of external power for launch. Then require beamed power throughout the flight, with the provision that the plane can still land if all ground stations fail to provide power. But the plane starts and ends with less weight than a normal plane does because it's not carrying fuel, so it just might be feasible.
Then again, you can also manufacture hydrocarbons from atmospheric CO2 given energy input.
All of the electric airplane work I've seen is either highly experimental (e.g., solar-powered aircraft), effectively powered gliders, or some very small and not-particularly-capable 1-2 person craft.
I mean, it's cool that humans won't have to give up the skies entirely, but we've also got perfectly viable aircraft with no engines whatsoever, for which a ground-tow launch is a present reality.
If you're looking at a credible commercial passenger or freight aviation model, this ain't it.
https://en.wikipedia.org/wiki/Electric_aircraft
Fuel synthesis is something I've discussed elsewhere in this thread. I actually think the US Naval Research Lab's concept of using seawater as both an H2 and CO2 source is inspired -- there's about 140x the CO2 by volume than in air.
It has a energy density slightly lower than Jet Fuel[1], and increasing supply (thanks to new techniques for extraction and some huge gas field finds) and stable cost in the US[2].
Tupolev is developing a LNG power plane, and claims it will cost 40% less than a conventionally fueled aircraft to operate[3].
[1] http://en.wikipedia.org/wiki/Energy_density#Energy_densities...
One characteristic of gas that makes predictions more difficult than oil or coal is that wells tend to peak and fail very suddenly. Which makes sense: you're extracting a gas, not a fluid, under pressure. While oil can be extracted, effectively, by sucking harder, or by forcing water into wells (what Saudi Arabia's been doing for years now), gas flows until it doesn't. Experience to date with fracked natural gas suggests that wells peak even faster, often within a year.
See for example: http://www.oilempire.us/naturalgas.html
http://oilprice.com/Energy/Natural-Gas/Shale-Bust-North-Amer...
As for NG as an aviation fuel: while it tends to perform well on a energy/weight basis, it's not so hot on energy/volume, and presents more significant storage and handling challenges. Where liquid fuels will stay in any reasonably contained tank, LNG needs either refrigeration or pressure to be viable. I'm not saying it's impossible but I'd strongly suspect it's much less practical than liquid fuels, so long as they're available.
That Russian NG aircraft has been under development for four decades and still isn't available. I take any paper-engineering estimates with several tons of salt. Of the touted benefit, carbon monoxide emissions reduction really isn't an issue: CO is a problem in confined environments such as garages and warehouses, in which commercial aircraft rarely operate. In the open atmosphere, CO both dissipates and reacts fairly quickly (forming CO2). Of itself it's not a long-term persistent atmospheric pollutant.
Similarly, NOx and hydrocarbon emissions are results of incomplete combustion and principally represent problems in urban smog where you've got large numbers of vehicles operating in a constrained area. They're not a particular concern in the wide-open reaches most flights occupy most of the time.
The problem with alternative fuels for aircraft is that jet fuel is still so darn cheap and there is no crisis right now. So none of these are economically viable...yet.
Note that "peak in 2030" and "60 years proven reserves" aren't incompatible statements. The problem is that post-peak, it gets a lot more expensive (in terms of energy cost) to extract.
There's also the rate of consumption growth to take into account -- find an annual rate, apply the rule of 72, and realize that in the last period you're using as much as you have in all the previous ones, combined.
And no, there's probably not a whole lot more waiting to be discovered ... at least not anywhere that's readily accessible. Prospecting for mineral resources has been pretty bloody extensive, the types of formations in which natural gas is found are well understood, and any of those which are accessible have been accessed.
What remains is going to be what's difficult to get to, or difficult to get to market (natural gas doesn't ship well in barrels -- it's got to be compressed, liquified, or piped).
Yeah, maybe there's untapped reserves in Antarctica or Greenland, but by the time we're going after that, we'll have a few other concerns at hand.
http://en.wikipedia.org/wiki/Peak_gas
The information is outdated from 2009, we have a lot more than that now since fracking just took off in the last few years.
Dr. Anthony Hayward CCMI, chief executive of BP stated in October 2009 that proven natural gas reserves around the world have risen to 1.2 trillion barrels (190 km3) of oil equivalent, enough for 60 years' supply if consumption is non-increasing, and that gas reserves are trending upward.
A quick check turns up a Motley Fool piece stating that global NG consumption is growing at 2.2% annually, or doubling every 32 years. The ten-year average has been 2.7% for a 26 year doubling.
http://www.fool.com/investing/general/2013/05/09/growth-in-g...
That's reflected as well in BP's annual review for 2013:
http://www.bp.com/en/global/corporate/about-bp/energy-econom...
The "gas reserves are trending upward" comment is consistent with the passage immediately preceding in Wikipedia noting that new discovery estimates are hard to establish, so they're often amended upwards. The increasing reserves noted by BP's CEO aren't the result of new finds, but of revised estimates of old finds. And new gas field discoveries peaked in the 1970s, 40 years ago. We're not finding new gas, we're simply recognizing how much was already found.
Fracking also isn't turning up new gas fields, but is allowing known plays to be further extracted. Again, it's digging further into what we'd already known about.
So: given BP's 2013 report of proved reserved of 187 trillion cubic meters, present consumption of 3,314 billion cubic meters, and an annual growth trend of 2.7%, we'll actually exhaust reserves by 2047. With a 2.2% growth trend, we'll last until 2050.
The interesting thing is that the impact of peak LNG is difficult to model. For example, most of the modeling for peak oil didn't anticipate the rapid shift to LNG use, which has moderated the price impact on oil.
I find any predictions of peak gas made prior to 2009 extremely suspect, as they don't take account of extraction from shale oil fields. See, for example the predicted production graph on [1], which predicts increases in US production out to 2040. I find that graph reasonably defensible, and it doesn't take into account non-US sources (eg Qatar, Brazil & Australia all have huge gas fields).
I don't disagree with the concern about peak oil and peak gas. I just find it extremely difficult to predict what it means - especially since the technologies associated with the gas industry are rapidly changing.
[1] http://en.wikipedia.org/wiki/Peak_gas#Recent_US_peak_predict...
A more interesting and accurate view is argued by Gail Tverberg of "Our Finite World" blog (also "Gail the Actuary" at The Oil Drum): oil prices are constrained between the minimum supply cost imposed by extraction costs, and the maximum demand price based on use value. There are a number of analysts who've cited a price ceiling between around $80 and $115 (my money's on the higher end), over which, if prices rise (because of extraction costs), the global economy tanks.
Another way of looking at this is by considering the productivity of energy on a $GDP/barrel basis -- you can compute this by taking national oil consumption and dividing by GDP -- Wolfram+Alpha allows this easily. The present world price is around $110/bbl and has been reasonably stable there for the past few years. In the US, that barrel produces around $1000 of GDP (though there's a fair argument that this is the result of outsourcing more energy-intensive activity). For China and India the number's closer to $450 - $500/bbl.
Which means that between the oil cost of $110 and the economic value of $450 is all the value that India can access from that oil.
They might be able to increase this through efficiency improvements, but practically, increasing the price of oil means foregoing the previously economically viable activities which produced a low but positive benefit. Or, in other words, raising the cost of energy is an inevitable damper on economic output.
Yes, fracking's seen a transfer of energy use from both coal and oil to natural gas, where such substitution's been possible, but NG supplies are distinctly limited, and I've posted the total reserve exhaustion dates based on present consumption, growth trends (which "years of supply" arguments always leave out), and proven reserves. The dates aren't far off (I can't see my post from this page, but it was ~2030 - 2050 as I recall based on 2.7% to 2.2% growth -- not all that distant). And we don't have an option beyond gas (other than coal, which is suicide from a climate perspective) that we can simply dig out of the ground.
I find any predictions of peak gas made prior to 2009 extremely suspect, as they don't take account of extraction from shale oil fields.
Fracking doesn't produce new gas finds, it increases what can be extracted from known ones. As with peak oil, the story with peak gas is that the biggest discoveries are behind us: about 40 years ago during the 1970s. Fracking is only increasing the rate at which we're extracting a nonrenewable and finite resource.
Richard Heinberg and Gail Tverberg are two sources I'd strongly recommend for more on what the actual dynamics are.
http://www.ourfiniteworld.com (her "getting started" links are a great primer)
http://www.postcarbon.org/ Heinberg's published numerous books, The End of Growth covers much of the economic impact, Snake Oil addresses oil and fracking specifically.
Even absent energy storage density, you've got challenges of power profile (fuel cells love constant operating load, aircraft are anything but), powerplant siting (do you really want to hang your fuel cells outside the fuselage? How are you going to cool them), and motive mechanism (props are more efficient but far slower than turbines, electric turbines are possible but inefficient).
Trains are amenable to electrification, though arranging for that over tundra and a Bering Straight crossing would be an interesting challenge. Energy requirements in general for ground transport are vastly lower than for heavier-than-air powered flight.
Planes are more efficient than cars, so why do you think aviation of all things will become too expensive to be viable?
You have an unrealistically pessimistic view on things. Fuel will only get cheaper, not more expensive.
No it hasn't. You are forgetting to adjust for inflation:
http://inflationdata.com/Inflation/images/charts/Oil/Gasolin...
And that graph is gasoline - if you graphed all energy it would look even better.
http://www.eia.gov/forecasts/steo/realprices/ (too bad it's not logarithmic - it's hard to read without it).
It's basically only the last decade that prices went up - before that it was all down.
> Also, writing off a factor of five, when talking about an industry (transportation) where engineers would kill puppies for another 5%.
I'm not writing off the difference I'm saying that the difference is not enough to make it "non viable" - just more expensive. If we were going to cut back on things because of energy costs, aviation is not what we would cut.
Look up thermoeconomics / biophysical economics / ecological economics for more on this theme. Santa Fe Institute and the EconoPhysics Forum also have some interesting work: http://www3.unifr.ch/econophysics/
http://www.bp.com/en/global/corporate/about-bp/energy-econom...
Otherwise, I agree with you that a factor of five is not negligible.
If I had talked to you 15 years ago you would comment on how gas keeps getting cheaper. It's corrected a bit since then, but adjusted for inflation and taking the long view it's not very expensive right now.
http://inflationdata.com/Inflation/images/charts/Oil/Gasolin...
NB: I'm looking at the cost of oil not necessarily of refined gasoline, using BP's reporting.
The post-2000 price is unprecedented in the prior century.
Note too that the US price was stabilized through production quotas established by the Texas Railroad Commission, in place from 1945 - 1971. They were lifted as US peak oil occurred, and extraction rates could not be increased. This set the stage for the 1973-74 oil embargo (earlier attempts at middle-east oil embargoes had been tried, but were not successful due to excess US extraction capacity).
http://www.bp.com/en/global/corporate/about-bp/energy-econom...
A train achieves 100 - 500 ton-miles/gallon.
A ship such as the Emma Maersk achieves about 1500 ton miles/gallon.
Moreover, if it gets down to it, a ship or train can drag the additional fuel it needs along with it, even if that is some multiples less energy dense than present hydrocarbons. Aircraft are limited by their lifting capacity, and under most scenarios, the battery weight required (assuming conventional batteries) would exceed the maximum takeoff weight.
Though ships require prodigious amounts of fuel and travel long distances, I ran some calculations suggesting you could run the Emma off of LiON batteries -- they'd only take up about half her cargo capacity. I still don't think you'd want to.
I have a hard time seeing fuel getting cheaper, though among the benefits of, say, a solar-driven electricity-to-fuel synthesis using seawater as carbon and hydrogen feedstock is that the cost would be constant. Your sunlight and water aren't going to go away or get more expensive over even geological time, and PV is also based on an abundant material (silicon, plus dopants). So long as population is kept in check, you've got an option for a constant-cost fuel supply for the future. Even if that's more expensive than today, assuming the net cycle EROEI is below a technological civilization sustaining threshold (estimated at between 6:1 and 9:1 by Charles A.F. Hall), we might pull things off.
Then there's just other resources and pollution issues to be concerned with.
Only a tiny faction of fuel is used for airplanes - so save all the hydrocarbons for them, and use the other energy sources for land based things. (And if necessary it's not that hard to make hydrocarbon fuel from sunlight and air - you can pretend the hydrocarbons are a battery.)
We have enough energy sources on this planet excluding sunlight for over 100,000 years. And that includes population growth! Include the local asteroids and the sun and we have enough for longer than I care to predict.
Pessimism like yours has been a constant for hundreds of years now, and it repeatedly makes the same error: It assumes no change, just the continuation of existing trends.
There is some value in it, in that it makes us more frugal, but let's not overdo it.
So, tell me, what's your alternative energy supply budget look like?
Please provide references and sources for consumption and reserves.
What's your population estimate?
Additionally, how do you account for: climate change, sea level rise, phosphorus depletion, topsoil loss?
Thanks.
FYI: Aviation fuel is about 13% of total US petroleum consumption. 36,017 million gallons in 2012, of 6.748 billion barrels of oil consumed.
Sources:
http://www.faa.gov/data_research/aviation/aerospace_forecast...
http://www-formal.stanford.edu/jmc/progress/cohen.html
4 Billion years worth of Uranium on earth. And there's 4 times as much thorium. So 20 billion years then.
We're using about 3 times as much energy per year as when the paper was written, but then again we've found more uranium since then. Even if you want to cut the number in half to account for those that's still 10 billion years - cut it by 10 if you like, for energy usage increase, and that's still 1 billion years.
It doesn't matter what adjustment factors you want to use (more energy usage, more uranium found), we aren't going to ever run out.
> Additionally, how do you account for: climate change, sea level rise, phosphorus depletion, topsoil loss?
Climate change and sea level rise are non issues since nuclear power will be widespread before those things cause any problems. Phosphorus is never actually depleted - it just gets moved from one place to another, it's not possible to actually use it up. If it gets expensive (note: expensive, not rare) it will be profitable to mine it from sewage and the mouths of rivers (which is where it goes).
Same for topsoil, the nutrients that make it good don't get used up, they just get moved into plants. Eat the plant, then put it back.
> Aviation fuel is about 13% of total US petroleum consumption.
I said energy consumption, only 1/3 of which is oil. Don't forget we can make aviation fuel from energy plus air (or preferably some coal and water). And we have a LOT of coal, if we stopped using it for energy and instead made it a feedstock for carbon in aviation hydrocarbons we'll never run out.
Better would be to get carbon from plant waste, hulls, straw, etc. Remove the carbon and make fuel, remove the potassium and make fertilizer. All you need is energy to make this work.
I've addressed a 62,000 year supply estimate for thorium. The author makes a massibe substantive underestimation of present total energy consumption. Correcting for this, using his abundance and reserves estimates the supply is good for 42 years: http://redd.it/23nvqs
NB: Thorium is not present in seawater at any appreciable concentration, and the uranium seawater trick doesn't apply.
Climate change and sea level rise are non issues since nuclear power will be widespread before those things cause any problems.
There's a baked-in several-degrees rise already, and a very significant lag in concentrations and climate effects. We'll be seeing the consequences, it's a matter of how much and for how long. I've seen estimates of 300 - 1000 years for the atmospheric CO2 balance to return to preindustrial levels even if all human emissions cease. See: http://www.nature.com/climate/2008/0812/full/climate.2008.12... http://blogs.edf.org/climate411/2008/02/26/ghg_lifetimes/
There's also the problem that a large portion of carbon emissions aren't due to fossil fuel emissions directly: concrete, agriculture, deforestation, and cattle are all sources. As well as other greenhouse gasses, some with higher effects than CO2, some with longer atmospheric residency. It's complicated (and no, I'm not fully versed in specifics). But these will continue to have to be addressed.
Same for topsoil, the nutrients that make it good don't get used up
Topsoil itself is eroding and being washed away. The soils of the great plains have literally decreased, by many feet, since farming and ploughing began in the mid-19th century. Nutrients aren't merely taken up by plants but are then transported off the farmland, to be eaten and dispersed. Added nutrients wash away with irrigation water fouling rivers (don't move along the lower Mississippi if you can help it) and forming offshore dead zones in the Gulf of Mexico, Yellow Sea, and elsewhere, due to algae blooms and oxygen starvation.
You're ... well out of your depth and highly underinformed (or misinformed) on all these points.
Don't forget we can make aviation fuel from energy plus air
I've addressed that multiple times elsewhere on this post. I see seawater rather than air as a CO2 + H2 feedstock as being much more viable. It's still tremendously energy intensive, and my estimate is that replacing present US petroleum consumption would likely cost ~$16 - $24 trillion between the fuel synthesis and energy inputs. I consider that plausible (amortize the costs over 40 years, roughly $2000 per man woman and child at the low end, about 4% of GDP over that period). Assuming the estimates hold.
https://news.ycombinator.com/item?id=7718584
https://news.ycombinator.com/item?id=7719535
Better would be to get carbon from plant waste, hulls, straw, etc.
Bullshit. Not nearly enough biomass: http://globalecology.stanford.edu/DGE/Dukes/Dukes_ClimChange...
Again: you're way out of your depth here. Get educated.
This train seems like a similarly colossal waste of money that could serve the same GDP purpose while building something of massive novelty value.
I vote yes.
And also: http://www.scmp.com/magazines/post-magazine/article/1318178/...
I wonder how worried the Russians would be about Chinese migrating to Russia. The population of all of Siberia is about 40 million.
It would take only "2 days" to get to the US via this train, and the Russians would have to cooperate of course. Heck, we don't even have a train from Alaska to Seattle yet.
It might make sense for freight, in which case "high speed" is not really necessary (well, it does help increase bandwidth). But for people? It will still be cheaper and fast to fly...maybe even more efficient considering that planes can fly in straight lines, mostly.
[0] http://en.wikipedia.org/wiki/Great-circle_distance
[1] https://farm5.staticflickr.com/4030/4622898186_e71984d836.jp...
All of my flights between Beijing and Seattle are via the arctic, but I doubt a train could achieve since it would have to cross the Bering straight between Asia and NA, and the topology is still extremely mountainous, unless it is completely underground or they drill through a lot of mountains, they will have to divert.
Heck, the only way to drive from Seattle to Fairbanks or Anchorage is by diverting east in the Yukon to avoid the mountains on the panhandle (cities like Juneau and Ketchikan are not even connected by land for that reason).
Oil is preferred to coal for ships for several reasons, among them that oil can be pumped, while coal has to be shoveled or otherwise managed -- and rebalancing a ship's coal bunkers underway was a significant operational concern.
Recoaling is another -- it takes longer and is less convenient than loading up with even no. 6 fuel oil (which must be heated to flow).
And there's ash removal to be concerned with, as well as the indirect power generation of steam as opposed to diesel engines (which at ship scale are truly impressive).
Pelletized fuels address at least some of those concerns. They're not a direct substitute in existing powerplants though, and I've got my grave misgivings as to just how much energy can be derived from biofuels in any regard, though marine transport is very efficient overall in energy per ton-mile of cargo moved.