Plausibility of Modern Coal Powered Ships and Heaters?

[Napoleonrules]

All of this is nice and theoretical for bringing back coal, except for one big giant elephant in the room- global climate change and the problems of excess human-caused carbon in the atmosphere is real and exists. No, we can't bring back coal-powered ships, nor should we, and I hope no homeowner ever changes their house to coal for a heating source. That's horrible. There is no "clean coal" as far as carbon is concerned, clean coal was a term to describe the scrubbing of sulphur from the by-product of burning coal, and it did a great job of eliminating acid rain in the US; the "tarnishing" or turning of copper roofs to green actually takes over 10 years longer now than it did in the 1960s and 1970s because we've done a great job of eliminating sulphur; but clean coal as in no carbon output or even a carbon output less than that of natural gas has not been proven to be cost-effective, is not widespread, and does not exist in large-scale nor is it planned to be continued beyond existing "test plants". A steam-punk TL is the only one I can think of as having wide-scale coal beyond what OTL already uses too much of, and in that scenario you're ATL ends with- we all die of climate change by the 1980s.

 

[b0ned0me]

In 20 years a diesel ship would consume $211,480,280 to $223,675,540 of fuel (fuel costs of $10,574,014 to $11,183,777 for year for fuel oil and diesel, respectively), while a coal ship would consume $8,034,520 to $29,842,540 of fuel (fuel costs of $401,726 to $1,492,127 per year). Total system costs would be $249,880,280 to $262,075,540 for diesel and $267,714,520 to $289,522,540 for coal.

That's capital and fuel, but what about MRO? As I understand it, one of the biggest difficulties with coal is that yoiu have a load of complex heavy machinery to handle the fuel/combust/exhaust element to get out the thermal energy, then another whole set of complex heavy high-precision gear to handle the feed water/boiling/condensing element which transforms the energy, and then even more complex high-precision turbines and gearing to finally get the work done. All of these need skilled people to operate and maintain, and are subject to wear.
By comparison even a big modern diesel is a miracle of simplicity. Squirt in fuel and air. Gaseous exhaust comes out, thermal energy transformed in situ and transferred directly to prop shaft without gearing. Job done. Even added complexity like a turbo is minor compared to the normal level of shenanigans in a turbine plant...

 

[Summoner]

All of this is nice and theoretical for bringing back coal, except for one big giant elephant in the room- global climate change and the problems of excess human-caused carbon in the atmosphere is real and exists. No, we can't bring back coal-powered ships, nor should we, and I hope no homeowner ever changes their house to coal for a heating source. That's horrible. There is no "clean coal" as far as carbon is concerned, clean coal was a term to describe the scrubbing of sulphur from the by-product of burning coal, and it did a great job of eliminating acid rain in the US; the "tarnishing" or turning of copper roofs to green actually takes over 10 years longer now than it did in the 1960s and 1970s because we've done a great job of eliminating sulphur; but clean coal as in no carbon output or even a carbon output less than that of natural gas has not been proven to be cost-effective, is not widespread, and does not exist in large-scale nor is it planned to be continued beyond existing "test plants". A steam-punk TL is the only one I can think of as having wide-scale coal beyond what OTL already uses too much of, and in that scenario you're ATL ends with- we all die of climate change by the 1980s.

I dont think we will see a wide spread conversion to coal in terms of home heating. People want push button convenient fuels that are quick simple and easy for them; hence the proliferation of oil and gas boilers and furnaces. Solid fuel fire require tending which eliminates it from many people's consideration.

The coal I am talking about is anthracite which burns with a hot blue flame, no smoke and low sulfur. It is a smokeless fuel and not like the characteristic images of coal (belching smokestacks and locomotives under full steam). That coal is bituminous coal which burns with smoke and stink.

There is an economic cost to using oil for instance for home heating. Last year when heating oil was at an all time high, it was costing thousands to heat a home for a season. Oil was $3.91 a gallon. A ton of anthracite is roughly $300. If we compare to coal on a BTU to BTU basis you need roughly 175 gallons of oil per ton of coal. It costs almost $700 to for 175 gallons of oil vs $300 a ton of anthracite- over twice as expensive. (This is an overly simplified comparison of heating fuels and not considering myriad of other factors such as boiler efficiency etc...). You also have the advantage by using coal of paying American wages and not sending dollars to the middle east.

 

[Napoleonrules]

I dont think we will see a wide spread conversion to coal in terms of home heating. People want push button convenient fuels that are quick simple and easy for them; hence the proliferation of oil and gas boilers and furnaces. Solid fuel fire require tending which eliminates it from many people's consideration.

The coal I am talking about is anthracite which burns with a hot blue flame, no smoke and low sulfur. It is a smokeless fuel and not like the characteristic images of coal (belching smokestacks and locomotives under full steam). That coal is bituminous coal which burns with smoke and stink.

There is an economic cost to using oil for instance for home heating. Last year when heating oil was at an all time high, it was costing thousands to heat a home for a season. Oil was $3.91 a gallon. A ton of anthracite is roughly $300. If we compare to coal on a BTU to BTU basis you need roughly 175 gallons of oil per ton of coal. It costs almost $700 to for 175 gallons of oil vs $300 a ton of anthracite- over twice as expensive. (This is an overly simplified comparison of heating fuels and not considering myriad of other factors such as boiler efficiency etc...). You also have the advantage by using coal of paying American wages and not sending dollars to the middle east.

Agree with you on everything but the last two words. You meant "not sending dollars to Canada". Petroleum and petroleum products in the US comes primarily from domestic sources and Canada is the largest source of foreign oil imported into the US (2014- at 37% of all foreign oil Canada outpaces all Persian Gulf countries combined at 20% and all OPEC countries combined at 35%, Saudi Arabia is second at a distant 13% and Mexico third at 9%). As far as I know Canada is not a threat significant enough to make us want to switch to coal. We export 12 million short tons to the Netherlands (our largest destination of exporting coal) and import 8 million from Colombia (73% of all imported coal to the US) it's a weird economy we live in, but I guess we have to give Colombia something other than cocaine to send us.

 

[Delta Force]

That's capital and fuel, but what about MRO? As I understand it, one of the biggest difficulties with coal is that yoiu have a load of complex heavy machinery to handle the fuel/combust/exhaust element to get out the thermal energy, then another whole set of complex heavy high-precision gear to handle the feed water/boiling/condensing element which transforms the energy, and then even more complex high-precision turbines and gearing to finally get the work done. All of these need skilled people to operate and maintain, and are subject to wear.
By comparison even a big modern diesel is a miracle of simplicity. Squirt in fuel and air. Gaseous exhaust comes out, thermal energy transformed in situ and transferred directly to prop shaft without gearing. Job done. Even added complexity like a turbo is minor compared to the normal level of shenanigans in a turbine plant...

O&M is 10% to 20% of capital costs for diesel over a 20 year period (PDF page 64 and 65 here). I think that's likely total costs, not per year. That means an 80 megawatt diesel plant would cost $3,840,000 to $7,680,000 to maintain over 20 years.

Coal has $37.80 per kilowatt fixed O&M per year and $4.47 variable O&M per megawatt hour generated (PDF page 10 here). That gives a cost of $60,480,000 fixed O&M and $18,795,460 variable O&M over 20 years.

Adding it to the capital and fuel costs from earlier, total lifecycle costs over 20 years at 30% capacity factor are $253,720,280 to $269,755,540 for diesel and $346,989,980 to $368,798,000 for coal.

With 35% capacity factor it becomes $261,854,137 to $278,358,445 for diesel and ($38,400,000 plant cost, $219,614,137 to $232,278,445 fuel costs, and $3,840,000 to $7,680,000 fixed O&M) and $348,021,902 to $370,668,692 for coal ($259,680,000 plant costs, $8,343,540 to $30,990,330 fuel costs, $60,480,000 fixed O&M costs, and $19,518,362 variable O&M costs).

It cost diesel $8,133,857 to $8,602,905 to increase capacity factor by 5%, but coal only $1,031,922 to $1,870,692. I'm going to run some analysis to see where the break-even point is.

 

[Delta Force]

Here are the scenarios. It would appear that a coal ship needs a capacity factor of around 40% to break even. In other words, the coal plant shouldn't be any larger than it has to be, and the ship shouldn't spend too much time in port. It's probably best to operate on long routes.

High Variable / (Low O&M, Low Variable)

Step 1. (259,680,000 + 60,480,000) + 1,870,692(X) = (38,400,000 + 3,840,000) + 8,133,857(X)

Step 2. 320,160,000 + 1,870,692(X) = 42,240,000 + 8,133,857(X)

Step 3. 277,920,000 = 6,263,165(X)

Step 4. X = 44.37% capacity factor

High Variable / (High O&M, Low Variable)

Step 1. (259,680,000 + 60,480,000) + 1,870,692(X) = (38,400,000 + 7,680,000) + 8,133,857(X)

Step 2. 320,160,000 + 1,870,692(X) = 46,080,000 + 8,133,857(X)

Step 3. 274,080,000 = 6,263,165(X)

Step 4. X = 43.76% capacity factor

High Variable / (Low O&M, High Variable)

Step 1. (259,680,000 + 60,480,000) + 1,870,692(X) = (38,400,000 + 3,840,000) + 8,602,905(X)

Step 2. 320,160,000 + 1,870,692(X) = 42,240,000 + 8,602,905(X)

Step 3. 277,920,000 = 6,732,213(X)

Step 4. X = 41.28% capacity factor

High Variable / (High O&M, High Variable)

Step 1. (259,680,000 + 60,480,000) + 1,870,692(X) = (38,400,000 + 7,680,000) + 8,602,905(X)

Step 2. 320,160,000 + 1,870,692(X) = 46,080,000 + 8,602,905(X)

Step 3. 274,080,000 = 6,732,213(X)

Step 4. X = 40.71% capacity factor

Low Variable / (Low O&M, Low Variable)

Step 1. (259,680,000 + 60,480,000) + 1,031,922(X) = (38,400,000 + 3,840,000) + 8,133,857(X)

Step 2. 320,160,000 + 1,031,922(X) = 42,240,000 + 8,133,857(X)

Step 3. 277,920,000 = 7,101,935(X)

Step 4. X = 39.13% capacity factor

Low Variable / (High O&M, Low Variable)

Step. 1 (259,680,000 + 60,480,000) + 1,031,922(X) = (38,400,000 + 7,680,000) + 8,133,857(X)

Step 2. 320,160,000 + 1,031,922(X) = 46,080,000 + 8,133,857(X)

Step 3. 274,080,000 = 7,101,935(X)

Step 4. X = 38.59% capacity factor

Low Variable / (Low O&M, High Variable)

Step 1. (259,680,000 + 60,480,000) + 1,031,922(X) = (38,400,000 + 3,840,000) + 8,602,905(X)

Step 2. 320,160,000 + 1,031,922(X) = 42,240,000 + 8,602,905(X)

Step 3. 277,920,000 = 7,570,983(X)

Step 4. X = 36.71% capacity factor

Low Variable / (High O&M, High Variable)

Step 1. (259,680,000 + 60,480,000) + 1,031,922(X) = (38,400,000 + 7,680,000) + 8,602,905(X)

Step 2. 320,160,000 + 1,031,922(X) = 46,080,000 + 8,602,905(X)

Step 3. 274,080,000 = 7,570,983

Step 4. X = 36.20% capacity factor

 

[BlueTrousers]

I did see, years ago, a serious suggestion from the 1970s for a coal-fired steam plant on a merchant ship. It was contended that for a bulk carrier transporting coal, it would be economically viable to use coal firing. The coaling facilities would already exist, by definition, so the capital expenditure would be minimal. Since steam turbines were widespread at the time, the machinery wouldn't be particularly unusual other than the fuel.

Not one such ship was ever built. That's probably an indication of the viability of the idea, despite the fuel cost advantages.

 

[Delta Force]

I did see, years ago, a serious suggestion from the 1970s for a coal-fired steam plant on a merchant ship. It was contended that for a bulk carrier transporting coal, it would be economically viable to use coal firing. The coaling facilities would already exist, by definition, so the capital expenditure would be minimal. Since steam turbines were widespread at the time, the machinery wouldn't be particularly unusual other than the fuel.

Not one such ship was ever built. That's probably an indication of the viability of the idea, despite the fuel cost advantages.

If a few hundred coal or nuclear powered steam plants were built for ships, that would certainly bring down the capital costs and further enhance the economics. The issue of course is getting that level of orders, and also the possibility of public concerns for coal and nuclear powered ships. There's probably less concern for both in the 1970s.

 

[Barry Bull]

Another thing to consider is that a ship could be equipped with a larger coal fired power plant to achieve higher speeds. Because coal is cheaper than petroleum it would still have lower fuel costs, but the ship could potentially transport more cargo in the meantime. A coal fired ship could be twice as fast as a petroleum fired ship and would consume four times as much fuel, but it would have only 60% the fuel cost. Ships are expensive to operate and time is very much money for them, so there could be a niche for fast bulk transports.

Don't forget about the increase in weight due to change of engine and fuel, which affect speed. And the necessary change in design may decrease tonnage available for cargo. Fuel cost is just one of many variables in the calculation.

 

[BlueTrousers]

Don't forget about the increase in weight due to change of engine and fuel, which affect speed. And the necessary change in design may decrease tonnage available for cargo. Fuel cost is just one of many variables in the calculation.

And in fact volume - the kinds of ships where speed is at a premium are the ones where volume is also at a premium. Coal plants are larger for equal power than oil plants, thanks to the lower energy content.

That's why this is most viable for bulk carriers - it's perfectly economical to build a slightly bigger, slightly slower ship if it means you can use much cheaper fuel.

Incidentally, the RN studied coal power in the 1970s - the conclusion was that it was more economically viable, at least on warships, to convert the coal to liquid fuel ashore.

 

[Barry Bull]

And in fact volume - the kinds of ships where speed is at a premium are the ones where volume is also at a premium. Coal plants are larger for equal power than oil plants, thanks to the lower energy content.

That's why this is most viable for bulk carriers - it's perfectly economical to build a slightly bigger, slightly slower ship if it means you can use much cheaper fuel.

Incidentally, the RN studied coal power in the 1970s - the conclusion was that it was more economically viable, at least on warships, to convert the coal to liquid fuel ashore.

While technology improves, the wear and tear caused by coal is still a hassal to deal with. Oil is much more "clean" in this sense, which means smaller engine and less service requirement, reducing engineering crew size.

 

[Summoner]

I did see, years ago, a serious suggestion from the 1970s for a coal-fired steam plant on a merchant ship. It was contended that for a bulk carrier transporting coal, it would be economically viable to use coal firing. The coaling facilities would already exist, by definition, so the capital expenditure would be minimal. Since steam turbines were widespread at the time, the machinery wouldn't be particularly unusual other than the fuel.

Not one such ship was ever built. That's probably an indication of the viability of the idea, despite the fuel cost advantages.

Reminds me of the liquefied natural gas carriers being built right now. Many of these ships can be fueled from the boil-off natural gas from their transport tanks and like your example, the fuel facilities would exist at their ports.

 

[BlueTrousers]

Reminds me of the liquefied natural gas carriers being built right now. Many of these ships can be fueled from the boil-off natural gas from their transport tanks and like your example, the fuel facilities would exist at their ports.

That's actually why LNG carriers were the last steam turbine ships built (excepting nuclear ones) - it took a long time to design and build diesel engines that would run on natural gas boiloff.

 

[Summoner]

That's actually why LNG carriers were the last steam turbine ships built (excepting nuclear ones) - it took a long time to design and build diesel engines that would run on natural gas boiloff.

Interesting. I thought natural gas was already in use as a fuel in "diesel" type engines (compression ignition). Do you know what the engineering hurdle was?

 

[NORGCO]

That's actually why LNG carriers were the last steam turbine ships built (excepting nuclear ones) - it took a long time to design and build diesel engines that would run on natural gas boiloff.

Side question/admission of ignorance: So what replaced steam turbines?

I remember hearing that some new warships - Spruance class cruisers - were supposed to get gas turbine engines developed from the RB-211 Rolls Royce aircraft engine. The fuel consumption issues were said to be prohibitive for civilian shipping, in the same sense that the M-1 Abrams tank got a gas turbine engine but nothing since has, fuel consumption was one of the things people bitched about when that was new too. Claimed it was a crippling defect making the whole tank worthless...

Ok, is this just me being old and out of touch? I know the M-1 did actually work out well in the end.

Also, what happened to fluidised bed combustors? I distinctly remember a lot of publicity about how this was going to coal the equivalent of oil in terms of convenience of use and cost etc. The coal was going to be ground to powder and blown by high pressure air making it effectively a fluid. Presumably it didn't work or what?

I can't be the only ancient relic who wonders about this stuff.

 

[BlueTrousers]

Interesting. I thought natural gas was already in use as a fuel in "diesel" type engines (compression ignition). Do you know what the engineering hurdle was?

Side question/admission of ignorance: So what replaced steam turbines?

Diesel engines modified to run on natural gas. I've no idea why it took so long to make them commercially viable, but they've only really come along in the last decade or so.

I remember hearing that some new warships - Spruance class cruisers - were supposed to get gas turbine engines developed from the RB-211 Rolls Royce aircraft engine. The fuel consumption issues were said to be prohibitive for civilian shipping, in the same sense that the M-1 Abrams tank got a gas turbine engine but nothing since has, fuel consumption was one of the things people bitched about when that was new too. Claimed it was a crippling defect making the whole tank worthless...

Ok, is this just me being old and out of touch? I know the M-1 did actually work out well in the end.

Aeroderivative gas turbines are old news - the Spruance class was built in the 1970s with LM2500s, which are related to the General Electric CF6. The MT30 is loosely derived from the RB.211, and the operative word there is 'loosely'; it's used on the Queen Elizabeth class carriers, the LCS, and the Zumwalt class destroyer.

They're a bit too thirsty for commercial transport use except in niche roles. Gas turbines excel when high power is required for low installed weight and low volume - they're ideal as a boost plant, for example. Warships and high speed craft are obvious applications, but there are actually a lot of aeroderivative gas turbines on oil platforms. There, they can burn what's essentially waste gas, and for some applications (compressors) they supply direct mechanical power.

Also, what happened to fluidised bed combustors? I distinctly remember a lot of publicity about how this was going to coal the equivalent of oil in terms of convenience of use and cost etc. The coal was going to be ground to powder and blown by high pressure air making it effectively a fluid. Presumably it didn't work or what?

AIUI, fluidised bed combustors make coal much easier to work with and improve performance a lot - they're commonplace onshore. For shipboard use, though, they don't do anything about the poor energy density of the fuel, which is what cripples coal firing.

 

[1940LaSalle]

Back on the topic of space heating with coal: there are still a few homes in the greater Philadelphia area that heat with coal (the handful I'm aware of are in old-line southern NJ industrial towns, with residents who've been in those homes for perhaps 60 or more years). The problem is that the distribution mechanism for home heating with coal has essentially vanished.

While there are plenty of fuel oil dealers, only the older ones-going back to the inception of home heating with oil-would ever have had the capacity to deliver coal, and nearly all have dropped carrying coal. (Again, I can think of one in the immediate area.) You'd have to have multiple dealers investing in coal tipples, dump trucks, and rail spurs--as well as have homes retrofitted with coal chutes and coal bins. I question you could even get the necessary hardware for a coal chute any longer, in fact.

I will stipulate that a coal furnace can be hand fired and go nicely for 24 hours, and will keep a home pleasantly warm even if the power goes out (I know, from experience in Baltimore in the blizzards of March 1958). But the move away from coal, I believe, is largely irreversible on economic and distribution considerations, except perhaps in areas close to coal fields.

Coal is also very dangerous to extract in conventional mining (see for example the ever-present methane hazard). Strip mining with heavy equipment is not environmentally friendly on the short term. All in all, coal is now / likely will be the province of large stationary power generating plants, as opposed to ocean- or rail-going vehicles or homes.

 

[alexcoppo]

Coal is also very dangerous to extract in conventional mining (see for example the ever-present methane hazard).

There is no need for methane, just coal dust in air is a wonderful explosive (see Mount Mulligan disaster). Even "safe" stuff like flour, if properly dispersed, can explode . The sooner we can kiss bye bye to coal, the better.

 

[Summoner]

Back on the topic of space heating with coal: there are still a few homes in the greater Philadelphia area that heat with coal (the handful I'm aware of are in old-line southern NJ industrial towns, with residents who've been in those homes for perhaps 60 or more years). The problem is that the distribution mechanism for home heating with coal has essentially vanished.

While there are plenty of fuel oil dealers, only the older ones-going back to the inception of home heating with oil-would ever have had the capacity to deliver coal, and nearly all have dropped carrying coal. (Again, I can think of one in the immediate area.) You'd have to have multiple dealers investing in coal tipples, dump trucks, and rail spurs--as well as have homes retrofitted with coal chutes and coal bins. I question you could even get the necessary hardware for a coal chute any longer, in fact.

I will stipulate that a coal furnace can be hand fired and go nicely for 24 hours, and will keep a home pleasantly warm even if the power goes out (I know, from experience in Baltimore in the blizzards of March 1958). But the move away from coal, I believe, is largely irreversible on economic and distribution considerations, except perhaps in areas close to coal fields.

I respectfully disagree. I am in Southern NH and hundreds of miles away from Pennsylvania coal fields and have located at least 5 coal dealers in my immediate vicinity (and a few more south towards Boston). I'd imagine in Philly/Baltimore area there would be many more. While I agree the delivery mechanisms of the past for coal has vanished or disappeared, it doesnt mean this product is impossible to find. Sure we might not have fully loaded trains of coal leaving Pennsylvania on a daily basis for New England markets like 80 years ago but I would be hard pressed to say coal is dead from a home heating perspective. The economics of coal are hard to ignore, its price per BTU cant be beat and it has several advantages over hardwood (anthracite forms no creosote in the chimney for instance).

I know of several coal burners near me that once a year hire a trucking firm to haul a fully loaded trailer up from Pennsylvania and they split a 20-30 ton load amongst themselves. Instant stockpile of heating fuel for next few years. The other guys who burn just get a 3-5 ton yearly order from hardware stores, agway, tractor supply etc... Coal is not always shipped loose. They ship it in 50 pounds bags too; all wrapped together on a wooden skid which any delivery operation can handle. In fact, most places (around here at least) that carry wood pellets will also carry coal.

Regarding the coal bin issue you raised, Id say its irrelevant. People who want a coal bin can have it easily built (inside or outside the home) out of regular lumber with a chute and door too. Something any competent carpenter/framer can do.

I'd admit that considering today's generation and how accustomed they are to push button heating fuels, coal or even wood are not going to be common heating choices if easier options are present. I mean who wants to have to load solid fuel, tend the fire and then ash out? Its cleaner/easier to work a thermostat and IMO, that's what killed coal for the majority. Then you have the environmental concerns (another nail in the coffin) as you have alluded to which has relegated coal to only those truly dedicated to using it. Most coal burners wont advertise it and are reluctant to admit they burn out of fear of backlash from neighbors. Its easy to hide as anthracite smokes and stinks far less than a typical wood stove. I only found out it was still a viable choice about 3 years ago and consider it a viable choice for myself on purely economic reasons. And I dont consider tending a fire once or twice a day to be a hassle.

 

[Delta Force]

And in fact volume - the kinds of ships where speed is at a premium are the ones where volume is also at a premium. Coal plants are larger for equal power than oil plants, thanks to the lower energy content.

That's why this is most viable for bulk carriers - it's perfectly economical to build a slightly bigger, slightly slower ship if it means you can use much cheaper fuel.

Incidentally, the RN studied coal power in the 1970s - the conclusion was that it was more economically viable, at least on warships, to convert the coal to liquid fuel ashore.

Can coal be converted to heavier petroleum products without the need for expensive facilities? Most attempts have tried to make lighter fractions such as gasoline and kerosene, but what if the aim is just to acquire things such as bunker fuel, fuel oil, tar, bitumen, etc.