Interesting concept for off grid, or just a dream.

mcgivor

Found this link interesting in concept, wonder if it works as planed.
https://www.curbed.com/2016/1/22/10844376/solar-powered-hydrogen-home-thailand

Solray

Lol. There is a reason those are only used in remote unattended locations. I wouldn't want to be within a mile of that thing.

WaterWheel

It's a take off of the old "hydrogen generator" a lot of guys built and installed on their cars to supplement the gasoline the carburetor supplies.        Yes they do provide a small amount of hydrogen that supplements the gasoline and I've seen several on operating vehicles but the alternator works much harder but.... I do know one guy who carefully documented the fuel mileage difference when the unit was operating and he was getting several more miles per gallon of gas with the hydrogen generator working.       He and I opened the unit to refill it with water and it was a fairly simple design and had to be refilled with about 3 quarts of water once a week.

At the same time he was basically driving with a very unstable bomb under the hood.   He took power directly off  the alternator instead of his battery so it would never run if the engine was not running but in an effort to clean the lines of hydrogen before shutting down the engine he also had a switch in the cab so he could shut it down a few seconds before he turned the ignition off.      It pulled 40-50 amps at 12v if I remember correctly (separate amp gauge in the cab).     I wonder if with that constant high load the alternator may keep putting excess power out chronically overcharging the battery.
Since it was pulling power from the alternator I suspect the alternator couldn't provide the required 40-50 amps for full hydrogen generation at engine idle so to an extent the generator was probably somewhat self regulating.

Estragon

> @Solray said:
> Lol. There is a reason those are only used in remote unattended locations. I wouldn't want to be within a mile of that thing.

They can be quite safe. The tech is fairly mature, but AFAIK the main hurdle in commercial acceptance is cost and lifespan of catalyst.(platinum?).

MarkC

Don't think it's likely there is any new technologies involved - possibly catalytic electrolysis for better efficiency of H2, O2 generation and state of the art fuel cell technology.  Sure like to review the "economic" calculations and the claim that it beats batteries for energy storage.  I designed (and oversaw startup) of electrolytic cells that produced molecular chlorine gas - for a number of years.  The technology evolved from asbestos to ion exchange resin "membranes" and one of the main concerns was loss of membrane integrity.  I hope that is resolved with H2 and O2 - a potential reaction of serious consequences.  H2 storage is a real challenge.  H2 gas at low pressures requires huge storage space (maybe a bomb shelter ).  Putting 15,000 psig compressors/storage of dense H2, in a home environment is quite a safety/maintenance challenge.  Innovation is great - colonizing the sun is not - even if it can be done (IMHO)!  

With the $$$$'s spent, I'll bet a Tesla SolarCity would cost less with the ability to throw in several Tesla Model 3's for both transportation and energy storage AND not require an industrial maintenance crew to "fix" when something breaks.

BTW, I have a similar opinion of the H2 automotive initiative - thermodynamically and mechanically, a nightmare. 

HOWEVER - I've been proven wrong on many an occasion - eating crow is one of my specialties - just ask my wife.

Marc Kurth

MarkC said:

Don't think it's likely there is any new technologies involved - possibly catalytic electrolysis for better efficiency of H2, O2 generation and state of the art fuel cell technology.  Sure like to review the "economic" calculations and the claim that it beats batteries for energy storage.  I designed (and oversaw startup) of electrolytic cells that produced molecular chlorine gas - for a number of years.  The technology evolved from asbestos to ion exchange resin "membranes" and one of the main concerns was loss of membrane integrity.  I hope that is resolved with H2 and O2 - a potential reaction of serious consequences.  H2 storage is a real challenge.  H2 gas at low pressures requires huge storage space (maybe a bomb shelter ).  Putting 15,000 psig compressors/storage of dense H2, in a home environment is quite a safety/maintenance challenge.  Innovation is great - colonizing the sun is not - even if it can be done (IMHO)!  

With the $$$$'s spent, I'll bet a Tesla SolarCity would cost less with the ability to throw in several Tesla Model 3's for both transportation and energy storage AND not require an industrial maintenance crew to "fix" when something breaks.

BTW, I have a similar opinion of the H2 automotive initiative - thermodynamically and mechanically, a nightmare. 

HOWEVER - I've been proven wrong on many an occasion - eating crow is one of my specialties - just ask my wife.

Great post

Photowhit

Interesting, but if they can achieve "...the electrolyzer achieves 80 percent efficiency" that is just one part of the equation as MarcC has said. Storage is the biggest issue. Low pressure here's a 10,000 gallon's stored in propane tanks, I think he says each 1000 gallon tank stores the equivalent of 3 gallons of gas!

https://youtu.be/Vel9LH57RII

Solray

Estragon said:

> @Solray said:
> Lol. There is a reason those are only used in remote unattended locations. I wouldn't want to be within a mile of that thing.

They can be quite safe. The tech is fairly mature, but AFAIK the main hurdle in commercial acceptance is cost and lifespan of catalyst.(platinum?).

Nuclear power plants can be quite safe as well, but I don't want to live next door to one. You go ahead though.

MarkC

Photowhit said:

Interesting, but if they can achieve "...the electrolyzer achieves 80 percent efficiency" that is just one part of the equation as MarcC has said. Storage is the biggest issue. Low pressure here's a 10,000 gallon's stored in propane tanks, I think he says each 1000 gallon tank stores the equivalent of 3 gallons of gas!

Mike was definitely ahead of his time - 2006, he went off-grid - over ten years ago with what must have been emerging technologies at that time.  What a pragmatic inventor and it appears he even got grant money and some "public utilities" backing - might as well work the system.  His use of "geothermal" (of sorts) and combined heat cycles for water heating via freon condensing is something an equipment packager ought to commercialize right now and offer for sale!  What a grand experiment - especially at that time.

OTOH, I would not select the H2 route - the storage costs, the amount of 200 psig on-site hydrogen gas, compression, electrolysis, fuel cells - just no way, especially if you have an in-place natural gas supply for backup generation.  For one carbon out of four hydrogen atoms, I wonder if the carbon "footprint" of using natural gas is actually smaller than the complexity of manufacturing/operating and maintaining a hydrogen fuel generation system.  Anyone know of such a study?

Photowhit

MarkC said;

I would not select the H2 route 

Agree completely!

Pretty much the point I was trying to make with the very low energy density of storing as a gas, and energy costs of storing as a liquid....

peakbagger

There was a much publicized project in Maine several years ago to install a H2 storage system for a PV installation at the Chewonki Foundation which is youth outdoor/development facility. Several  firms donated time and materials to put in place. It was designed around a prototype high pressure electrolyzer. I think high pressure was relative. It got a lot of press but its seemed to disappear off the face of the earth once the initial ribbon cutting was held. I have subsequently search for high pressure electrolyzers and haven't seen any.

I used to work in a pulp mill that had a low pressure gas accumulator for various gases from the pulping process, including hydrogen sulfide. It was big "beach ball" about 20 feet in diameter, the bottom was stainless steel with mylar diaphragm mounted at the halfway point. There was top stainless section vented upwards. The gas would go in at fairly low pressure and the diaphragm would fill the upper dome. We would then meter it out slowly back into the disposal system. Hydrogen sulfide will burn and even explode but the flame velocity is very slow. It was definitely a potential bomb  but we dealt with it. Nothing I would want within any distance of my home. The same thing would work with H2. 

BB.

One thing that is a big issue with hydrogen is "hydrogen embrittlement" of the tanks/pressure lines/etc.

https://en.wikipedia.org/wiki/Hydrogen_embrittlement

A big problem with Salt Water (bridges), deep sea wells, and high strength steels:

http://www.materialsforengineering.co.uk/engineering-materials-news/bridge-failure-sparks-concern-over-hydrogen-embrittlement/52014/

I would not dozens of steel pressure tanks near my home without a whole bunch of research/testing.

-Bill