Dirty Clean Power

Yesterday no.10s output fluctuated a bit, hitting 237mv mid-day then it was at 239mv by 10:30pm.  This morning at 9:14am it was at 245mv, 3mv over yesterday's high, and at 11am it was at 247mv 0.88ma.  We're slowly gaining day over day.  It's still a little erratic in its behavior(what conditions trigger output changes), but the output is otherwise very stable, so I'm guessing it just needs a little more time to stabilize and grow.  

No.9 is rock solid as usual, and it just passed TWO months of continuous discharge, with ZERO signs of fatigue or fuel depletion.

10mv or more.  I'm guessing the cooler temps at night are more favorable for reproduction while the warmer are better for energy production..?  Who knows what's going on for sure, but gains are gains.  I completed the insulation and finally reached a 20degC cell temp.  Recycled bags do wonders.  I will build an enclosure at some point soon.

We have somewhat normal behavior.  Cell no.10 was reading 231mv 0.82ma @ 15.5degC around 8:45am today.  I was half expecting that something more dramatic would have been waiting this morning.  It's steadily rising with the ambient temps, right now bumping off of .83ma @ 232mv reading about 16.5degC.  We'll see if we can't coax a good daily rise out of it now.  It has to at least meet the output of no.9 in the next few days or it's just not worth fussing with it anymore.  For now though, this mess is still proving somewhat educational.

Within 4 hours of turning the heat up, cell no.10s output bottomed out at around 217mv 0.78ma cell temp ~ 18degC, then fairly rapidly began to rise.  Two hours later at around 10:30pm we're reading 230mv 0.82ma, cell temp holding around 18degC.

It's close to 11pm now, no.10 is bouncing off 0.83ma at 231mv.

The morning expects some kind of surprise, for certain.  

This is one of those moments where automated continuous data logging would be amazing.  The graphs would certainly look a lot prettier.

So, after some minimal deliberation I decided the most productive way to move forward concerning cell no.10 would be to see if I can resurrect the warm loving microbes.  

I would have re-innoculated the substrate when I replaced the top half of the soil substrate anyhow, so they should be present.  The fish tank heater was ill-equipped to maintain 10degC, which seemed like the area that the current culture liked, but it tops out at about 30degC.  Which sounds perfect for the warmer cultures.

I'll let you know how far the output falls, with any luck though it will begin rising again shortly thereafter.  

And if all else fails, it'll get the hose.  We'll start fresh with completely new substrate, and get a chance to inspect the electrodes for signs of corrosion.  

In natural soil similar shifts happen when the seasons change, microbes that are dormant in the summer due to heat become active in the cooler fall weather.  I know that this is a gross over-simplification of these incredibly complex bio-chemical processes, but also something that seems easily testable in these circumstances.

So, we shall see what happens when the warm water circulator gets up to temperature and the fuel cell starts warming up.

As I had guessed this morning arrived with low temps and a Gain in output by no.10.  While no.9 is at its lowest in days.

Yet, this is totally fascinating.

One culture established in warmer temps with appropriate moisture levels from the start, no fiddling with the substrate.(no.9)

The other(no.10) established in aprox. 10degC cooler ambient temps, first incubated with excess water(~2x) in the soil until a strong fermentation was started.  Then it was cooled and the much too wet top half was removed and replaced with lightly dampened substrate.  

I'm truly curious now, if the warm fermentation period might have killed off the warmer loving soil microbes and simply made the colder loving ones go dormant?  If so, then this procedure should be repeatable.  

A mass "burn out" due to all the warm water and nutrients would explain the huge output spike and subsequent fall.  Like yeast in sugar water.

Another curiosity, if no.9 has both sets of microbes, and possibly that is why it holds its output in the cold as well as it does?

Now I've just got to decide if I want to chase the idea of cold loving fuel cells or call this cell a failure and reset it completely.  

It seems I may be onto something with the notion of cooler temps being better.  Aside from the fact that no.9 seems just fine with it.

Cell no.10 has registered a 2degC rise in temp and a corresponding significant drop in output.  I've consequently lowered the heater temp as low as it will go, at best though that's only 2 or 3degC lower than where it was set before.  It may be time to try removing it from the heater, but I want to give it another night to see if we get a repeat of this behavior.

It's cold this morning, reading 12degC at no.9 and 13degC at no.10..

Yet we are doing quite well.  No.9 is still exceeding 1ma and no.10 gained 6mv from my last reading of 221mv at 10pm last night.  Honestly, that's an incredible gain for the coldest time of the day...  Kind of puzzling.  My assumption is that some of the microbes actually prefer the colder temps.  We'll see, if the nightly gains continue I may need to adjust my incubation strategy.

Presently, and always set at 271ohms.  I just realized, I don't think I've made mention of that.

There they are..  In all their glory.

Yesterday cell no.10 continued falling until it bottomed out at 215mv 0.77ma around mid-afternoon.  Since then it has been climbing steadily.  At the time of this log, no.10 is gently settling into 223mv 0.8ma.  Just 10mv more and we will exceed the reassembly voltage of 232mv.  At that point I will consider the cell to be properly incubating... Finally.

Here's a mugshot of no.10, sporting the latest in fall fashions...lol.  That black dot is my temperature sensing location, just above that you can see some holes I poked in the container, closer to the substrate so heavier gasses don't puddle up and choke out the cathode...  No idea if they have helped honestly, once it has become fully stable I may experiment with them more.