Wave Powered Hydrogen System 

Correct Energy Solutions by XDOBS- 800-658-8745  sales@xdobs.com

A band of Ocean less than 14 miles wide is capable of producing a sufficient amount of Hydrogen to completely replace the 19.6 million barrels of oil consumed by the USA every day.

Of the wave based systems there are several designs which we have developed to various stages of completeness with one design which we believe represents the best strategy for large scale deployment as part of the National Plan to eliminate petrolum use as a fuel.  The following choices where the major contendors:

Our concept is a series of self contained float units each of which has floats capable of displacing about 600 cubic foot of air.   This size is large enough to make installing a local water condensation,   disassociation and secondary compression stage  in each unit so that only the anchor line and a high pressure  hydrogen lines need to be plumbed together.     The size on these units could range down to 10 cubic foot of displacement and up to 50,000 cubic foot displacement driven by the local sea conditions and customer desires.      The 600 cubic foot units are nice because they are big enough to be predominantly self contained and small enough to lift and place with standard ship board cranes.
 

Design options

All of these designs use a premise that it is better to consume the electricity locally to generate hydrogen which can be stored on site or delivered via pipeline to shore based consumers.   Any one of them could work but we have a favorite choice.

• Anchor based floats with linear or rotational electric generators paired with  traditional high efficiency electrolsyis units.   Advantage of using off the shelf components.   disadvantage of requireing large amount of copper and magnetics also requires more electrolsyis units than the market is capable of delivering at the current time.  In addition the current generation of eletrolysis units require more maintenance than is ideal and to reach reasonable economies of scale they must be sufficiently large that it complicates system design by requiring more cross unit plumbing.   This approach would be the fastest and cheapest to demonstration.
• A piezo electric strategy that converts wave energy into very high voltage pulses which is combined with a new generation ceramic transducers that allow hydrogen dissociation to be directly driven from the sea water which simplifies other concerns.  This strategy could be ideal due to extreemly long life,  low maintance and the ability of the ceramic transucers to self clean by chaning their voltage and vibration characteristics.   Unfortunatly the piezo materials needed are not manufactured at the scale needed and would require massive integration efforts for every unit.   This option remains our second favoirite because it shares the characteristic of allowing hermetically sealed units which are immune to damage by  the corrosive ocean enviornment.
• A flip flop float based system which converts a oscilating motion into mechanical energy that is directly converted through mechanical leverage into high pressure needed to reach the 2600F direct disassociation temperature where it becomes fairly easy to separte water into Hydrogen and Oxygen.  This system is ideally suited to deliver ultra pure water for this process using a distillation based process I is also ideally suite to a hermetically sealed flotation chamber which can easily withstand the worst seas and can be rapidly deployed in large numbers.   This process has one maintance challenge which is a compressor capable of withstanding the 2600F operating temperatures with low maintance while operating for extended periods of time.  The rest of the system  can be deployed and forgotten.   The heat based dissociation process has the ability to operate at higher efficiencies than electrolysis based approaches which means that a larger portion of the harvested energy is delivered in the form of usable hydrogen.  This approach is also  ideally suited to compressing hydrogen for storage and delivery.  This is our favoured approach because once the long life compressor is tested the system can be deployed in massive scales and it does not require extensive amounts of expensive copper.    Unlike most ocean based wind harvest systems this system has minimal impact on the surrounding ocean and floats low enough that it is unobtrusive.

Compressive float hydrogen generation overview

 This works by using a hermetically sealed chamber which tilts up and down as waves travel underneath it.   A specialized weight system travels back and forth from end to end.   The weight is mechancially coupled to a speicalized piston which where a small amount of air is compressed by a sufficient amount to heat it to over 2600F.   The heat in this gas is used to drive a water dissocation process and optionally a zinc binding process for the produced hydrogen.  

During the same cycle a a second compressive + vaccum cycle  at much lower pressures is used extra mositure from the ocean air using our propriatary Air to water techniques. This ultimately produces highly purified water which is used latter during the electroysis process.   By extracting the water from the moist ocean air we avoid chaning the salinity content of the water.

A given float can easily displace 600 cubic foot of water (4,488 gallons) 37,449 pounds.       The motion is mechanically levered to compress air in the sealed loop  to 5.78 ATM (68 PSI) to obtain 2600F compressive heating.      This is done in a  sealed loop so the high temp compressive component can be sealed for long life which also allows us to use specialized lubrication components for the high temperature compressor.   In reality we would design for 20% higher pressures to allow for system losses.   

We ultimately came up with a float design which even seals the moving weight system  inside a sealed chamber and which can be simply installed and anchored in massive flotillas.  This sealed strategy allows the units to easily withstand the worst weather but does have a weakness in that energy harvest actually goes down during extreme weather conditinos when the wave lenght period changes from the design optimum.  

The 2600F is used to heat small streams of ultra pure water to a temperature where they disassociate and can be separated.   This can be entirely heat driven or combined with electricity and it generally requires less electricity to drive the electroliziation proces as you the temperature approaches 2600F.    The hydrogen and oxygen can be extracted in the form  of gasses or combined into solids such as the Zinc Oxide approach. 

The same compressive strategy allows the system compress the hydrogen gas to the point of liquefaction but requires several intermediate cooling steps.     

One challenge with the heat based separation approach is separateding the oxygen and hydrogen gasses before they recombine.    There are a number of strategies for accomplishing this some of which have been funded by the DOE.  In the intial implemtnation even if we see a higher than desired recombination rate the simplicity of the system will still deliver favorable economics.    The best short term option is to use an electolsysis approach which becomes incredibly efficieint when operated at above 2,000F where the wave energy is supplying both the heat and the needed electricity.

The main concern with this strategy is a compressive piston and sleve system capable of withstanding the 2600F with long maintenance intervals.    Metals such as Titanium are operating at the edge of their envolope but newer ceramic composits are readily available that can withstand these tempratures.   There are a number of industries that regularly operate at these extended tempeatures such as high performance jet engines so while being esoteric and requiring carefule design and testing this is well within the realm of current technology.

The Energy in Context

This system is designed for optimal production in 5 to 6 foot waves on a 6 second interval.  This is a very common wave condition which can be found off most coasts.   A design tradeoff was chosen to use much smaller waves than typical designs so that we would have a much larger area of ocean surface to deploy the system on.       The design can with stand larger waves but they will actually generate less power becuase larger seas tend to generate longer wave periods.   Any seas which generate equal wave heights but shorter wave periods will increase production.    The design can be modified to accomplish optimal generation in most wave conditions.

To put the amount of energy in context a 600 cubic foot float will displace 37,449 pounds of water.  We can not use all of this so we cut the total displacement by 50% to 18,724 pounds.    Our design uses a shifting weight which moves back and forth as the float ends move up and down so we have effectively 8,000 pounds moving end to end twice per wave cycle over a 5 foot vertical distance.   When operating on a 6 second interval the the system will experinece 10 oscilations per minute and we harvest energy in both direction 20 strokes.     This gives us 8,000 pounds * 20 strokes * 5 foot = 800,000 foot pounds per minute.   A horse power is defined as 33,000 foot pounds per minute or 746 watts which gives us an energy harvest 24.24 HP or 18,083 watts.    We could probably push the weight up to close to 20,000 pounds which would nearly tripple our energy harvest but we will use 8,000 to be conservative.

A typical 600 cubic foot unit is 18 foot long by  5 foot high by but only 3 foot of height is used for draft purposes which makes the unit  11.1  rounded to 12 foot wide so in a space covering   216 square foot (20 square meters) we are harvesting 18,083 watts or  904 watts per square meter which tends to occur for more than 20 hours per day  so on a daily basis we are harvesting  18,080 watts per square meter versus the 1260 harvested by the best case solar pannels giving us a energy density 14.35 times greater than photo voltatics (PV) at a cost under 1/8th which gives us a net economic payback 114 times better than PV.

With 100% ocean coverage we could install 201 units per acre.    We can not  not cover the entire surface of the ocean with these since we need to be able to reach individual units for service  and we want to allow sunlight to reach the water surface so the local fish can take advantage of the new structures.     Assuming  a placment where we reach a 70% coverage we will have 151 units per acre which will harvest a total of   2,730,080 watts per acre per hour.     70% would represent a maximum feasible coverage 20% to 30% would be more typical.

Cuirrent state of the art for hydrogen requires 52,000 watts to disassociate and compress 1KG of hydrogen.    The 904,150 watts per acre is mechanical energy we have harvested.  Assuming we reach a 40% efficinecy conversion using the high efficincy heat dissasociation we can produce 21KG per hour per acre or approximately 420KG per acre per day assuming 20 hours of favourable waves.

A barrel of oil uses converts to 42 gallons of product per barrel (19.5 gas + 9 Fuel oil + 4 Jet Fuel + 11 Other).      So the Brookshire oil field which produces 600BPD is producing a net of  25,200 gallons of product  per day.     1KG of hydrogen is the energy equivelant of 1 gallon of gassoline which allows a direct converstion.      It would require approximately 60 acres (0.09375 square miles)   to produce the energy equivelance of  hydrogen.  It would require  9,060 of our 600 cubic foot units to cover that space.

The brookshire field sald dome covers 8,000 acres.   The ocean based hydrogen system could produce an equivelant amount of energy using 60 acres of ocean surface.

This ultimately works out to about 10BPD (barrels per day) per acre of installed system.     If we look at the 21 million barrels of oil per day  consumed in the USA  it would require 2.1 million acres or 32,812 square miles.       The USA controlls  4 382 645 square miles (11,351,000 km²) of ocean surface in the EEZ.   In other words less than 1% (0.00075) of the EEZ would supply 21 million barrels consumed.         The USA has 12,380 miles of coastline.  This means it would require 

Another way to look at this is USA coast covers an area of  band of ocean less than 3 miles wide to deliver the energy equivelance of 21 million BPD.  

Economics

The brookshire field is producing approximately 600BPD which at $60 per barrel is worth 1.08 million USD per month or 12.96 million per year.    Using a 30 year revenue basis this would place the approximate value of this field at 388.8 million.    As calculated above we would need 9,060 of our cubic foot units which gives us a maximum installed cost per unit of  42,913 per unit.   In reality we expect  these units to cost under $40,000  each for a total cost of  under  362.4 million.   This shows  a favorable valuation comparison between the two technologies.

Another way to look at valuation is time required to return the invested capital.  Using an installed cost of  $362 million the 9060 units would be producing  25,200KG of hydrogen per day or 756,000KG per month.   With a market value of $3.00 per KG it would be worth $2,268,000.       Using an installed cost of 362 million the payback period would be
  13 years.  There would be maintance and operation costs but those also exist with crude and the price of energy can be exected to continue to increase over the period so the actual payback period may be 1/2 the 13 years.

As volumes go up the price will come down quickly.  If the volumes needed for the national plan are installed the cost would drop by up to 60% which moves the payback period from 13 years to less than 6 years. 

Anscilarry uses of the heat energy

After being used to donate it's heat for the separation process the surplus heat is used to drive a TEC module (Thermal Electric Coupler) which generates DC power directly from heat differentials.    The remaining heat can be used to drive large scale desalination .       The systemn will be operating with some areas with more than 3,000F temperature differentials which is where TEC modules can perform with maximum efficinecy.      Some of the TEC power is used to operate on board systems and computers however a substantial amount is left which can be used to drive local electrolysis exported.

The TEC will not utilize all the heat so the remainder is used to drive large scale distillation when the pipeline or storage capacity to deliver the frresh water is available.      The amount of fresh  water available is orders of magnitude larger than what is produced by all the current desalination plants operating in the USA even when combined.

After fully utilizing the heat energy the oringal  gas is allowed to re-expand.   Due to expansion based chilling it  will be at very close to absolute zero and this cold is used to chill massive volumes of air which allows us to harvest the water we need for the separation process directly from the ocean air.     This process can harvest a lot more water than needed for electrolysis which can be stored or delivered to shore as an additional sellable items.   There is in fact sufficient cold energy available that the fresh water can be stored in specilaized submerged barges where it is frozen which can increase it's value when delivered to shore.   The Air to water system can be utilized in locations where enviormental concerns or water contamination would prevent desalination from being used.   The actual water harvest is part of our A2WH system.     

 

Storage and Delivery of the Hydrogen

The ideal implementation allows the hydrogen geneated to be delivered directly to shore via submerged pipelines.   In the context of a national plan the ideal location for these units is right at the boundry of the USA coastal waters about 100 miless off shore.   This can make the pipeline difficult due to water depths especially during the initial stages.  Eventually a pipeline which services the entire band could be used and theon shore legs would be held off util relatively shallow water is reached.   Underwater pipelines are well understood and are used on a regular basis by off shore oil rigs which have amassed a extrordianary level experties and best practices.

Sub surface storage

One challeng that must be solved in any large scale hydrogen system is storage of sufficient hydrogen to meet long term needs during peak demands.   This requirement can be combined with our short term storage problem in the form a speciallized bladders that contain the hydrogen submereged below the waves.   This approach allows us to use the weight of the water to  counter the hydrogen pressure which allows they bladders to be composed of relatively weak materials.

In the initial implementation these units would be designed to store the produced hydrogen at between 100 - 2000 PSI in specialized bladders.  These bladders would be ballasted such that they ride 50 to thousands of feet  below the ocean surface.  The pressure of storage is chosen by the depth of submersion such that there is a net 0.2 PSI positive pressure exterted by the water at the top of the bladder.  

Between 0 and 100F Hydrogen will weight about 3 pounds per cubic foot at 2000 PSI.   In an all scenarios the bladder will be at least 60 foot below the surface where is not subject to surface turbulence.    In ideal  scenario the bladder will be fare enough below the surface that the hydrogen can be kept at pressures slightly above whatever pressure the hydrogen supertankers or delivery barges will carry the fuel.    

According to standard formulas you get roughly 3 ATM 44 PSI of pressure per 100 foot of depth so to store the hydrogen at 300 PSI would require the bladder to be floating at roughly 680 foot in depth.      To equalize the flotation units as hydrogen is pumped in to these bladder  air is pumped out. 

Super tanker or barge delivery

 A super tanker would periodically  visit and upload the stored hydrogen for delivery until a pipeline or blimp infrastructure could be put in place.     By floating at depth the bladders would be low cost and would be immune to the surface weather storms.  These submerged bladders also have no free oxygen to react with so there is no explosion potential and even if ruptured the hydrogen will simply float to the surface and disburse.   Supertankers are mentioned first because hydrogen capable super tankers already exist and have amassed good quality of best practices data.   The cost of transport will be minimized because in most instances the fuel only has to be transported from it's sub surface storage point to the nearest pipline access point which will normally be under 150 miles.
 
As an alternative to the super tanker specialized automated barges can be constructed which use computerized guidance to automatically deliver hydrgoen to  pipeline access points points of storage where the fuel is delivered transferred into the onshore pipelines similar in strategy to how bulk oil is transfered from super tankers today.      In this context these barges would never have to travel closer to shore than several miles and they can burn a portion of the hydrogen they are tranporting for fuel.  They can be under powered because speed will not be a significant issue and since hydrogen even under extreeme compression is the compression ratio is chosen to keep the hydrogen slighly boyant in water it simplifies the vessle design.     GPS guidance couple with local ultrasonics can be used to guide the barges to offload points so the barges do not need to be manned.   The under sea local storage can be setup so that each storage location can contain 10 days of production which allows a limited number of barges to collect and deliver fuel from an extended area.   The barge design can be mostly flexible where it is held rigid by the pressure of the fuel it is transporting and kept rigid for the return trip by leaving a slight over pressure in the storage holds.

In the very long term the automated barge concept can be combined with a floating blimp which allows the the hydrogen to be delivered in bulk to inland locations wich can dramatically reduce pipeline and overland transport costs.

Reference:

• High-Temperature Water Splitting  by DOE EER  
• Nuclear Production of Hydrogen: the Key Points
• Milestone for H2 Production by High-Temperature Electrolysis  29 November 2004
• we may be able to produce hydrogen by breaking up water molecules in association with the high-temperature heat from nuclear power reactors, or through renewable energy  Rich Diver invents new way to make hydrogen for fuel
• Maximum output temperature from solar thermal troughs is 5,500C or 9,932F which is much richer than we would need.    A pressurized direct air system is producing 1,100C or 2012F more than enough to drive direct conversion to hydrogen. 
• THERMAL ANALYSIS OF PARABOLIC TROUGH SOLAR
  COLLECTORS FOR ELECTRIC POWER GENERATION collector efficiencies in excess of 73% where reported.
• Solar Energy System Design 
• Statement of George W. Crabtree Senior Scientist and Director Materials Science Division, Argonne National Laboratory Before the Subcommittees on Energy and Research Science Committee U.S. House of Representatives  July 20, 2005 
• 1 kg of hydrogen contains the energy equivalent of about 1 US gallon of gasoline.
• By weight, H2 has 4 times the energy capacity of gasoline but by volume it has 1/20th the energy capacity.
  
• http://www.hydrogen.org/Knowledge/w-i-energiew-eng2.html - 1 kg of hydrogen contains the same amount of energy as 2.1 kg of natural gas or 2.8 kg of gasoline. The energy to volume ratio amounts to about 1/4 of that for petroleum and 1/3 of that for natural gas. Water consists of 11.2% hydrogen by weight.  -   Hydrogen electrolysis conversion is possible at 50% to 65% with esoteric technologies claiming higher.
• http://www.solartoday.org/2004/may_june04/h2_afford_it.htm -  Available Electrolyzers have system energy efficiencies ranging from 56 percent to 73 percent without compression,.
• http://www.bellona.no/en/energy/hydrogen/report_6-2002/22869.html.. - Efficiency factors for PEM electrolysers up to 94% are predicted,
• http://www.windsun.com/Solar_Basics/Solar_maps.htm - Facts and statistics on Solar energy
• http://www.eia.doe.gov/emeu/cabs/Usa/Oil.html.. USA Oil production numbers
• http://www.gravmag.com/oil.html - Oil production numbers.  This report claims that USA consumes over 21 million barrels per day.
  
• http://www.energybulletin.net/4189.html - Bush, Iraq and the Hydrogen Economy  a nuclear viewpoint.   Includes some interesting numbers and financial calculations.
• http://ecoworld.net/ - Bush and Fuel cells.
• http://www.msnbc.msn.com/id/4177740/ - Hydrogen Economy possible in time?
• Solar Hydrogen Economy: Why We Need It Now -  By Wayne D. Reynolds, PhD.  http://www.evworld.com/general.cfm?pageIDENT=solar_h2economy.cfm&storyid=1001 
• http://en.wikipedia.org/wiki/List_of_countries_and_outlying_territories_by_area - Sizes of Countries and territories not including territorial waters.
• http://en.wikipedia.org/wiki/Exclusive_economic_zone - Exclusive Economics zones area coverage by country. 
• http://en.wikipedia.org/wiki/Geography_of_the_United_States - USA Geography overview - 12,380 miles of coast line. 
• http://findarticles.com/p/articles/mi_pwwi/is_200408/ai_n8556777 - Background information on Texeen / brookshire field in texas.
• http://sec.edgar-online.com/2003/02/19/0001002014-03-000071/Section8.asp - Additional notes Texen oil includes information on brookshire fields.
• http://www.beg.utexas.edu/mainweb/services/pdfs/giddings.pdf - Texas Oil fields background and economic impacts
• http://www.gravmag.com/oil.html - Good overall background of gasoline and petroleum industry.  
  

 

           thanks,  Joe Ellsworth
                       CTO of XDOBS.COM LLC                
                       435-657-2280 main
                       408-230-3780 cell
                       joe@xdobs.com