Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 07-26-2015, 03:51 PM   #1
soulnafein
 
Join Date: Jun 2013
Default [SS] Cost of Hydrogen

In GURPS Spaceships page 46 it shows that hydrogen costs $2000 per ton.
In a Traveller style game a typical 100-ton Scout Ship with 60 tons of cargo will need about 20 ton of hydrogen for a 2 parsec jump. That's a cost of $40K.

On GURPS Spaceships 2 it suggests that freight rates are $10 per parsec per day. So in a typical 2 parsec jump in a Traveller universe would be $140 per ton. In the case of full cargo, for the example above it would be a total of $140 * 60 = $8400.

Fuel Cost: $40K
Freight Revenue: $8.4K

What's wrong? Is the hydrogen cost too high or the Freight rates too low?
What changes do you suggest?
soulnafein is offline   Reply With Quote
Old 07-26-2015, 04:12 PM   #2
weby
 
weby's Avatar
 
Join Date: Oct 2008
Default Re: [SS] Cost of Hydrogen

Using a ship with just 3% of it devoted to cargo is normally not very cost effective for shipping freight.

But in general for Traveller it is better to use the Traveller costs and incomes as Spaceships seems to assume a few thing in their freight costs: No special costs for FTL travel(not true in traveller), low crew requirement(the example designs are such), massed need for trade causing mega freighters and long repayment times for ships(not unrealistic if you assume low wear value, low interest rates and low risk to losing ships).
__________________
--
weby's gaming stuff: http://weby.roto.nu
weby is offline   Reply With Quote
Old 07-26-2015, 09:43 PM   #3
sjard
Stick in the Mud
 
sjard's Avatar
 
Join Date: Aug 2004
Location: Rural Utah
Default Re: [SS] Cost of Hydrogen

Well, using GURPS Traveller Intestellar Wars for pricing:
Fuel is about $350/dTon.
Freight is $700/dTon/parsec for major or minor routes, and $800/dTon/parsec along branch routes.

If that helps at all.
__________________
MIB #1457
sjard is offline   Reply With Quote
Old 07-26-2015, 09:57 PM   #4
Flyndaran
Untagged
 
Join Date: Oct 2004
Location: Forest Grove, Beaverton, Oregon
Default Re: [SS] Cost of Hydrogen

I always assumed Hydrogen's cost was so high in SS, because in reality most easily accessible is locked in water. Getting it out takes energy that has its own added cost.
Traveller has power production that all but eliminates that hidden cost.
__________________
Beware, poor communication skills. No offense intended. If offended, it just means that I failed my writing skill check.
Flyndaran is offline   Reply With Quote
Old 07-26-2015, 10:32 PM   #5
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: [SS] Cost of Hydrogen

The cost of hydrogen is basically determined by the cost of producing and liquefying it; most of the time, the raw materials are quite cheap. As such, its price can realistically vary quite a lot depending on your tech assumptions.
__________________
My GURPS site and Blog.
Anthony is offline   Reply With Quote
Old 07-26-2015, 10:48 PM   #6
Kale
 
Kale's Avatar
 
Join Date: Aug 2005
Location: Cowtown, Canada
Default Re: [SS] Cost of Hydrogen

Quote:
Originally Posted by Anthony View Post
The cost of hydrogen is basically determined by the cost of producing and liquefying it; most of the time, the raw materials are quite cheap. As such, its price can realistically vary quite a lot depending on your tech assumptions.
I use an advanced gas giant refining economy in my campaign, making hydrogen fairly cheap. The PCs are also mainly operating in a star system that specializes in gas mining, so fuel is *very* cheap in system.
__________________
FYI: Laser burns HURT!
Kale is offline   Reply With Quote
Old 07-26-2015, 11:12 PM   #7
panton41
 
panton41's Avatar
 
Join Date: Jul 2005
Location: Jeffersonville, Ind.
Default Re: [SS] Cost of Hydrogen

Quote:
Originally Posted by Flyndaran View Post
I always assumed Hydrogen's cost was so high in SS, because in reality most easily accessible is locked in water. Getting it out takes energy that has its own added cost.
Traveller has power production that all but eliminates that hidden cost.
For what it's worth most industrial liquid hydrogen in real life comes from natural gas through a process called steam methane reforming. It's also often produced more or less on-site with a fairly short distance between the processing plant and the site that's going to use it. (Most industrial hydrogen is used to make ammonia.)

The real life price of liquid hydrogen (in 2002) was roughly $0.70/kg (roughly $650/ton) if processed on site and between $2.0-3.08/kg ($2,000 to $2,800/ton) if it has to be transported. Considering GURPS uses 2004 dollars and tries to base its prices on real life if at all possible this matches the value in Spaceships. I'd argue a science fiction spaceport probably produces it on site (real life spaceports do) and maybe go with $1,000/ton to represent profit and various fees and taxes, etc.
__________________
The user formerly known as ciaran_skye.

__________________

Quirks: Doesn't proofread forum posts before clicking "Submit". [-1]

My ebook page.

Quote:
"My mace speaks Goblin." Antoni Ten Monros
panton41 is offline   Reply With Quote
Old 07-26-2015, 11:30 PM   #8
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: [SS] Cost of Hydrogen

Producing hydrogen by electrolysis of water requires 285 kJ/mol or 142 GJ/ton or about 40 MWh, which is a couple thousand dollars at bulk electricity prices. Aqueous ammonia can be electrolyzed for a mere 27 GJ/ton; simple electrolysis won't work for methane and I'm not sure exactly what reactions are used. In space, I suspect icy asteroids containing ammonia ices are the easiest source of hydrogen.
__________________
My GURPS site and Blog.
Anthony is offline   Reply With Quote
Old 07-26-2015, 11:45 PM   #9
panton41
 
panton41's Avatar
 
Join Date: Jul 2005
Location: Jeffersonville, Ind.
Default Re: [SS] Cost of Hydrogen

Quote:
Originally Posted by Anthony View Post
Producing hydrogen by electrolysis of water requires 285 kJ/mol or 142 GJ/ton or about 40 MWh, which is a couple thousand dollars at bulk electricity prices. Aqueous ammonia can be electrolyzed for a mere 27 GJ/ton; simple electrolysis won't work for methane and I'm not sure exactly what reactions are used. In space, I suspect icy asteroids containing ammonia ices are the easiest source of hydrogen.
Quote:
Originally Posted by Wikipedia
Steam reforming of natural gas - sometimes referred to as steam methane reforming (SMR) - is the most common method of producing commercial bulk hydrogen. Hydrogen is used in the industrial synthesis of ammonia and other chemicals.[4] At high temperatures (700 – 1100 C) and in the presence of a metal-based catalyst (nickel), steam reacts with methane to yield carbon monoxide and hydrogen.

CH4 + H2O ⇌ CO + 3 H2

Additional hydrogen can be recovered by a lower-temperature gas-shift reaction with the carbon monoxide produced. The reaction is summarized by:

CO + H2O ⇌ CO2 + H2
There's a few other processes used in special cases and the oil refining industry produces elemental hydrogen as a waste product of other useful refining.
__________________
The user formerly known as ciaran_skye.

__________________

Quirks: Doesn't proofread forum posts before clicking "Submit". [-1]

My ebook page.

Quote:
"My mace speaks Goblin." Antoni Ten Monros
panton41 is offline   Reply With Quote
Old 07-27-2015, 01:16 AM   #10
Rupert
 
Rupert's Avatar
 
Join Date: Aug 2004
Location: Wellington, NZ
Default Re: [SS] Cost of Hydrogen

Spaceships clearly bases its prices on the default tech, which does not include a fuel requirement for FTL travel.

I ran into the same issue you did, and did some calculations based on a ship that was just the minimums for surface-to-surface freight transport, using my house-ruled Traveller ship rules:

That a jump drive is always one system in size (and costs the listed price for an FTL drive times (1+ J-number)/2)

That jumps take one system of hydrogen per parsec (because Spaceship designs require much bigger control systems, etc., than Traveller ships).
The result was the following:

Freight and Passenger Rates:

In order to account for the cost of jump fuel, prices are adjusted to the following: Cr300 per ton per parsec for freight, and passengers pay for each jump according to the following table:

Distance...Standard
J-1..........2K
J-2..........4K
J-3..........6K
J-4..........9K
J-5..........12.5K
J-6..........18K

Luxury fares cost three times as much, economy half as much, and low-berth one quarter as much.
These numbers do not allow for the extra mortgage repayments for the high-jump drives, just for the fuel costs. Also, as they were based on a ship that had the maximum cargo space (or passenger space) and assumed each voyage was with a full ship for the maximum jump range, PC's owning ships are unlikely to find these rates attractive (intentionally).
__________________
Rupert Boleyn

"A pessimist is an optimist with a sense of history."
Rupert is offline   Reply With Quote
Reply

Tags
spaceships

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 02:45 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.