Thursday, December 13, 2012

Fun With Polynomials

UPDATE:  The mother of all polynomial fits from the Canadian Medical Association Journal.

Here, we discuss how the outcomes of clinical trials may be affected by the extinction of all mankind and recommend appropriate changes to their conduct. In addition, we use computer modelling to show the effect of the apocalypse on a sample clinical trial. 

It looks like Roy Spencer may finally have given up using his third order polynomial fit for the UAH TLT record

September 2012

November 2012

Some, not Eli to be sure, might speculate because the  temperature was going up while the curve was going down, but just to join the party, Eli was looking at an interesting development in Graetzel cells (dye sensitized solar cells) in Science.  Briefly put some characters (Lee, Teuscher, Miyasaka, Murakami and Snaith) took the cell apart and put it together from scratch.  The original cells, first described in the 1990s had thin layers of light absorbing dye coated on an electrode coated with titania. A photocurrent then flows between the electrode and a counter electrode across an electrolyte.  Folks have been working on this cell for about 20 years and efficiencies have gotten up to 12% or so, about half of the best silicon cell, but a lot cheaper to build.  The new twist is to replace all the parts keeping the smile.  Time for a rebuild say Lee and friends, and they substitute the dye with an inorganic perovskite, the titania with alumina and the electrolyte with an organic conductor.  They get 11% efficiency, but it is early days.

Eli, reading the perspective by Norris and Aydil came across a figure showing that since 1975 the cummulative photocell electrical capacity doubles roughly every  2.45 years, but the fit is not quite linear.  Taking Dr. Roy's advice, why use two parameters when you can use four, Eli had a fit

 No problem by 2016:)  More conservatively, fitting a straight line on the semi-log plot which assumes the continued exponential growth, it is all OK by 2030.


Anonymous said...

c.60 and +300.

David B. Benson said...

Lst sentence makes no sense.

Hank Roberts said...

I've been reading that it may now make sense to replace solar thermal (hot air/hot water) collectors with solar PV and run the electricity through a resistance heating coil -- no plumbing. And also that it begins to make sense, instead of trying to make a living space completely airtight (and risking humidity and mold problems), instead, roof it with solar PV and dump the heat into the house, and let the air flow through keeping the structure dry just like we did with cheap fossil fuel home heating.

I think this may make sense.

Anonymous said...

Why do I read Pielke Jr.'s blog? His latest statement that managed to annoy me:

"Issues associated with the "hurricane deductible" likely played a role in NOAA's immediate reversal in setting up an assessment team to evaluate the agency's performanceon Sandy."

Nowhere does Pielke mention that the official statement actually involves FACA (, not hurricane deductibles, or what inside source he has in NOAA that has informed him about this deductible link...

(Mind you, I actually do agree with one of his broader points that it is dumb to have deductibles depend on whether an agency classifies a storm at landfall as a hurricane vs. a tropical storm vs. an extra-tropical storm, especially when such classifications can change with reanalysis)



Only five more suns until The End Of Shopping Days and the Great Olmec Calendar Reset

Rattus Norvegicus said...

Re: the update.

Why not a zombie apocalypse? A normal apocalypse is just so jeune et se quois, whereas a zombie apocalypse? Now you've got something!

Anonymous said...

The young person and himself watts (snicker)!

Quoi encore?

Je ne sais quoi! :-)

Cymraeg llygoden

John said...

Here's an even better way to save the planet:
Plot the efficiency of solar cells as a function of year. It goes up with time.
Next, extrapolate into the future.
At some time in the near future, efficiency will exceed 100%. This violates the 1st law of thermodynamics, but who cares? That's just negative thinking anyway.

At some point in the future, the efficiency will be so high that all the electricity needs in the US can be met by one football field covered with solar cells.

Which football field shall it be? I nominate the football field of the Kansas City Chiefs, whose record is currently 2-11. Nobody will notice anyway. And the Chiefs arguably aren't really a professional football team any more.

EliRabett said...

John, have you been consorting with engineers? - Eli

Anonymous said...

>100% efficiency?

More likely "cavorting with economists".

"Untainted by Physics"

-- by Horatio Algeranon

Engineers abide by physics
Aware of its constraint.
Economists abide by bizzics,
Which physics does not taint.