Sunday, February 15, 2009

Off grid energy storage - practical hydrogen?

I usually post only original material on my blog, but I came across a video so incredible, I wanted to share it. (This man is incredible as well.) Like my house, this guy's house has geothermal and solar power. He has a utility line run to his house (it was his original power source and still functions as a backup), but for some reason, he's chosen not to sell power back to the grid.

I'm not selling my power back either (I don't even have an umbilical from the grid here), so the question becomes... how to save the extra energy in the sunny months so one can use it in the cloudy months? Lead acid batteries can only do so much. His solution... split water to create hydrogen, store it in LP tanks, then use a fuel cell to convert the hydrogen to electricity in the winter. Brilliant! I looked into something like that, but I couldn't get the economics to work out for me. Heck, I couldn't even locate a fuel cell for less than 6 digits. Because I live 150 feet up on a hill (with another 150 feet to the ridge), some day I'd like to implement pumped-water-storage-hydro to bank my seasonal electricity peaks. But this guy has me thinking about hydrogen for storage again...



By the way, I've been using a 15 amp, 120 volt floor sander for the past 24 hours using nothing but my off-grid power system. (While I was sleeping, the neighbor kid ran the sander!) My point is not that I'm cheap and trying to milk the 24 hour rental for all it's worth (although that much is true). The point is, if I hear someone in the media or government say that solar power isn't practical, one more time, I'm going to lose it! Solar power is absolutely practical. It's also expensive, but it is not prohibitively expensive... even in Kentucky where the available solar resource is 70% of what it might be in California. On an inflation adjusted basis, off grid solar power is the same price as grid electricity was in the 1940's. Was fossil-fuel grid power practical in the 40's? Of course it was, so how could anyone say that solar power is not practical now? OK, energy storage problems not withstanding, but we can solve that too! Please check out the video if you have 7 minutes to kill. I love the twangy banjo sound track!

9 Comments:

Blogger Ed said...

Outstanding link! I'm an engineer and I'm blown away with all that that guy has done! I also have to add that your house continues to amaze and inspire me as well!

February 16, 2009 at 7:59 AM  
Anonymous Anonymous said...

Hmm. Interesting, but incredibly impractical with respect to storage. Why is he only pressurizing the H to 200 psi? That is an incredibly inefficient process. How much energy was used to make that field of 1k gal tanks? They even offer the caveat at the end as to the "high" cost of such a setup. I would love to know how much it actually cost, including the donated items.

Sorry to sound like a wet blanket, Thomas, but I think your methane digester idea has more merit.

Jim

February 18, 2009 at 10:55 AM  
Blogger Thomas Massie said...

Jim, I agree that his system is not a cost effective one to emulate. I think the donated fuel cell is probably worth a big chunk of change. Also, I think he is using a lab grade electrolisis machine. I could be wrong, but I think it is probably only 25% efficient at best. Still, he got it to work and I don't see a reason why that same system couldn't still be working 100 years from now, so that is admirable.

His storage system intrigued me the most. (neglecting for a minute, all of the embodied enrgy in all those tanks!) I need to store methane when I scale up my pilot plant to a bigger digester. A 1,000 gallon plastic tank full of methane at atmospheric pressure has only as many Kwhr's (or BTUs) as one gallon of gasoline. I was thinking of compressing the methane when (and only when) my batteries are full and there is extra solar power. I have also looked into compressed air as a storage medium. When they do it on a large scale, they heat the air before extracting energy from it - so they get a nice little boost. Works if you have extra heat from somewhere... hmmmm, where might I find that. :)

February 18, 2009 at 1:32 PM  
Blogger Whit said...

Nice story! It's always enjoyable to discover folks with a story of persistence.

February 19, 2009 at 3:30 PM  
Anonymous Anonymous said...

Neat setup, if on the obscenely expensive side.

@oldmilwaukee- Any reason you decided not to go with the compressed air? I'm working on a compressed air system in Colorado right now. Great blog and beautiful house.

-Chase

March 10, 2009 at 4:30 PM  
Blogger Unknown said...

This comment has been removed by a blog administrator.

May 4, 2009 at 3:38 PM  
Blogger AKpolarboy47 said...

I'm an engineer, and I love this video... However, let me respond to your claim that this is practical: "HAHAHAHAHAHAHAHAHAH".

May 15, 2009 at 9:25 PM  
Blogger Thomas Massie said...

AK,

Actually I'm not vouching for the practicality of hydrogen - just solar. I agree, the hydrogen system he has is not within a factor of 10 of being cost effective. I like that he built _something_ though!

Thanks for the comment!

May 16, 2009 at 11:06 AM  
Anonymous Jonson said...

Really great work.
Weldone...
I would like to hear more from you.

April 24, 2010 at 8:21 AM  

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