Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > The Poop Deck
Cruiser Wiki Click Here to Login

Join Cruiser Log Today

Thread Tools Search this Thread Display Modes
Old 09-12-2007, 06:04 PM   #1
Retired Mod
Lighthouse's Avatar
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984

The discovery has scientists excited by the prospect of using salt water, the most abundant resource on earth, as a fuel.


No need to worry about sea-levels rising any longer.


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Old 09-12-2007, 11:36 PM   #2
delatbabel's Avatar
Join Date: Jul 2007
Posts: 700
Send a message via AIM to delatbabel

Someone needs to go back to school and read up on the laws of conservation of energy, and the laws of thermodynamics.

Extracting hydrogen from seawater: 2 x H2O + energy(1) = 2 x H2 + O2

Burning the resulting hydrogen: 2 x H2 + O2 = 2 x H2O + energy(2)

Where energy(2) == energy(1).

In other words the energy that you use to create the hydrogen in the first place (by bombing it with radio waves, or electrolysis, or whatever) is exactly equal to the energy used when burning it (it's not the salt water that burns, but the hydrogen generated by bombing it with radio energy), HOWEVER heat dissipation and increase in entropy (read the 2nd law of thermodynamics) will ALWAYS mean that energy is lost in the process. So you can't use this on your boat to create free energy from the sea -- there's no such thing as "free" energy.

You always have to start with a higher energy (lower entropy) compound (such as diesel) and combust it in such a way as to create a lower energy (higher entropy) compound (such as CO2, water, smoke, fumes, etc) before you can gain any energy. Starting with water, extracting hydrogen, and then combusting the hydrogen to get water again, does not gain you any energy at all -- not in a "closed" system like a boat floating around in the water.

The only rational way to use hydrogen extracted from seawater to create energy is to (1) build a f**kin' huge power station, somewhere near the sea (2) use the power from that power station to electrically separate the hydrogen from the seawater, compress it and stick it in tanks and (3) ship those tanks to shore stations, boat owners, other countries, power companies, etc, who can then burn it to create energy. HOWEVER the energy used in (2) will always be more than the energy gained in (3). It makes a modicum of sense if the power stations are either massive pollution devices that nobody wants near their city (but can handle a clean hydrogen-burning generator nearby), or nuclear.

Find some desolate stretch of coastline somewhere, e.g. along the Western Australian or South Australian coast a long way from any people, build a big stack of nuclear power plants there, use those plants to extract hydrogen, and then ship that hydrogen around the world as a form of clean power. But that's another argument for another day.

And for those wondering about the three laws of thermodynamics, they are:

1. You can't win.

2. You can't break even.

3. You can't quit the game.


delatbabel is offline   Reply With Quote
Old 09-14-2007, 06:11 PM   #3
Trim50's Avatar
Join Date: Feb 2006
Home Port: Who cares really...
Vessel Name: T
Posts: 1,215
Send a message via Yahoo to Trim50


In general you are correct, however you can use electricity from solar and wind to perform catalytic electrolysis (hydrogen pump) to free your hydrogen from the bonds of oxygen and then store it in a keel based metal hydride. The energy balance works out, unfortunately the cost balance does not.


Trim50 is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Best Water Maker, Ac/dc/engine, Pump Type Trim50 Other Equipment 36 09-23-2015 05:01 PM
Salt Water Tap Replacement linnupesa Other Equipment 17 03-04-2011 06:09 AM
Hello From The Great Salt Lake kory The Tavern | Welcome Aboard 2 06-26-2010 03:38 AM
Old Salt, New Member, Now In Mexico totemthepole The Tavern | Welcome Aboard 1 11-25-2009 06:41 AM
An Old Salt Who Is Ready To Live Aboard And Cruise Chowan The Tavern | Welcome Aboard 5 11-17-2009 01:49 PM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

All times are GMT. The time now is 08:31 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0