Posted by Curbie on April 5, 2009, 10:35 pm
I know steam was in its hay-day before computers so obviously
computers were not needed then, but getting to a practical solar
device to generate electricity with-out running the number seems
un-likely at best and fatal at worst. You'll probably spend a huge
amount of time and waste some money chasing this idea, so let me
purpose another option. I don't think there any more of a chance of
getting to usable electricity from this idea as opposed to steam on a
small scale, but it's safer and cheaper to experiment with.
Algae can produce either sugar or oil, if this sound familiar it
should, if you collect 2 liter coke bottles, take off the label, add a
small amount of water and nutrients, then deposit them round say
with-in a 20 mile radius of your property, you can then retrieve and
analyze the algae that is growing in them for both sugar and oil.
The general idea is to find indigenous algae that contain either sugar
or oil, use selective cultivation to increase the % sugar or oil in
the strain and when and IF the basic numbers make sense, mass produce
the algae in a simple raceway pond to harvest for ethanol or
bio-diesel. Both solar thermal and algae are being produced at
commercial scale. I don't know what your water situation is, but that
could be a killer.
If this idea has appeal to you, let me know and I'll write something
up in a few days.
Posted by Tim Jackson on April 5, 2009, 11:01 pm
You'll probably find that when you've carefully selected the breed of
alga that wastes it's energy making it available to you, and started
growing it, it will be quickly displaced by some local thuggish breed
that keeps its energy to itself so it can breed faster, or makes lots of
cellulose to clog up your machinery.
I'm saying you'll have to keep your pond sterile, which is quite a
challenge. Ask a brewer, making beer is almost exactly the same discipline.
I did an inadvertent experiment a while ago, Against advice, I made
small a spring-fed pond as a garden water feature. After a few months
it grew algae in large quantities, the stringy cellulose sort that can
block drains, which it quickly did. You can't grow a culture in an open
pond like growing potatoes, there's a whole ecosystem already going on
Posted by Curbie on April 5, 2009, 11:41 pm
I agree with your assessment for non-indigenous strains of algae, but
in general (to my understanding) providing the exact nutrients for the
needs of your algae strain restricts its indigenous competition. The
commercial guys seem to be broken into two camps on your point, the
indigenous raceway camp and best producing photo-bio-reactor camp,
both camps have pros and cons which seemed pointless to chat about
unless there was interest. NREL seems to be advocating indigenous
raceway, Europe seems to advocating best producing photo-bio-reactor,
too many variables for me to make a blanket conclusion. But there may
potential in algae?
Posted by Winston on April 6, 2009, 5:25 am
You are on to something there, Curbie.
I saw a PBS show recently where a company used stacks of algae tubes
to change some portion of a biogas digester's CO2 output to oxygen.
Don't *faff*, dear.
Posted by Curbie on April 7, 2009, 5:45 am
I'm on to two somethings here the HYPE and the REALITY of the idea,
separating the two is only the first step.
Nature seems to have algae to provide whatever it needs, scientists
think they only cataloged 10%, the rest are either un-discovered or
dormant just waiting for nature's circumstances to throw a party for
them (the HYPE).
The REALITY is when we try to throw a party for algae to produce
something that nature doesn't need, as Tim points out, nature can send
algae to crash, contaminate, and spoil our party.
So, the two commercial solutions so far is find/grow an low-yield
indigenous algae in an open raceway (cheaper) OR use a best-yield
non-indigenous algae enclosed in photo-bio-reactor to try and protect
it from party crashers (more expensive). Both plans are subject to
A home-scale effort seems to me to rests on your ability to find a
suitable indigenous algae for the cheaper raceway plan,
photo-bio-reactors even home-built ones made with commercial tubes (or
tubes built from commercial sheets) is a BIG expense.
I experimented with 2 liter coke bottles (clear), peeling the label
off, gluing them end to end and configured horizontally (to avoid the
effects of gravity on the bottom bottle in a vertical configuration)
with a plastic tube running end to end for CO2 (air contains too much
oxygen that will poison algae contained in a photo-bio-reactor). Coke
bottles are trashed in huge amounts, I collected over 100 in a couple
hours by fishing through recycle bins of large apartment complexes
nearby. I'm confident I could collect 4000 free 2 liter coke bottles
for a 1000 gallon photo-bio-reactor in no time.
MORE MATH CHEESE derived from a European Photo-Bio-Reactor company who
published way too much technical information in their sales
literature, I knew the literature was created by the tech group
instead of sales group and was a business mistake when first saw it. I
checked back tonight and they replaced their technical information
with standard sales hype, but too late. I already go it.
I plugged their specs into a spread-sheet to produce ratios for
volume, algae, and individual nutrients per gallon which were
basically consistent between their 1, 10, 25, 50, & 100 ton
photo-bio-reactor products. Their products were tuned for a specific
best-yield non-indigenous oil-algae so individual nutrients per gallon
are not really relevant to my point.
The point is, using their ratios, for that specific algae, with a
year-round growing season (or heat to keep the algae party going) a
1000 gallon coke bottle photo-bio-reactor could only produce 500
gallons of oil for bio-diesel per year best case.
NOT GREAT, but then again, NOT BAD, but then again, TOO MANY UN-KNOWN
VARIABLES for me to run with the idea just yet. I think it has enough
merit to experiment (on the cheap) to try and nail down some of
variables to see if I can make the numbers work.