A few comments on photovoltaics (solar cells)

Updated 12/6/10

Solar Cells: one path to sustainable energy

. . . also called "photovoltaic" (PV) energy

. . . Some images:

http://inhabitat.com/wp-content/uploads/sunpower_main.jpg

http://www.greenfab.us/blog/wp-content/uploads/2009/02/solar-cells.jpg

http://www.scitoyscatalog.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=SOLARCELL&Category_Code=
http://keetsa.com/blog/science-and-technology/solar-power/solar-cells-run-off-like-printing/
http://blog.makezine.com/archive/2006/08/make_a_solar_cell_in_your.html
http://www.treehugger.com/files/2007/05/suntech_starts.php
http://www.metaefficient.com/architecture-and-building/skyscraper-gets-covered-in-7000-solar-panels.html

What is the future of PV, etc.?

. . . First, the "etc.":  http://blog.ted.com/2009/06/02/announcing_sing/

. . . Next, lets focus on the PV graph

. . . . . . curve fitting a straight line gives the slope

. . . . . . what is the slope? See hard copies

. . . . . . let's "Delphi it"!

Types of PV technology

. . . Example technological advance

. . . . . . Cost reduction approach: vacuum typically needed to deposit top layer of anti-reflective material, vacuum processing is expensive, spray-on technology is cheaper and under development

. . . . . . Thin film vs. regular

. . . Efficiency improvement (are these exponential?)

. . . . . . http://www.ijdesign.com/blog/Solar-Cell-Efficiency.jpg
. . . . . . http://www.allinsolars.com/images/Solar%20Cell%20Efficiency.gif
. . . . . . http://www.solarnavigator.net/images/pv_solar_module_efficiency_chart.jpg
. . . . . . http://www.tf.uni-kiel.de/matwis/amat/semi_en/kap_3/illustr/eta_development.gif


For general information on PV see: http://www.pveducation.org/pvcdrom


A major tipping point: grid parity

. . . check some graphs: see
. . . . . . image.google.com (query: grid parity)

Exercise: using a hard copy of Kurzweil's graph, figure out when PV will satisfy 100% of energy needs

. . . Assume world uses 15,000,000 (15 million) megawatts (per http://en.wikipedia.org/wiki/World_energy_resources_and_consumption)
. . . . . . Note: for simplicity, you may assume 10,000,000 if you wish

. . . Assume continued exponential growth
. . . . . . (straight line on log graph)

. . . Ok that's the mathematical result, but what do you think will really happen?
. . . . . . Why?

Oil: the Hubbert peak

Revised 11/29/10

Today: the Hubbert Peak

1. Who was Hubbert?


. . . Marion King Hubbert
(Oct. 5, 1903 – Oct. 11, 1989)


. . . Was a geologist at Shell


. . . Devised a way to predict
oil production for a given oil field


. . .and by extension for a given country






2.  ...and what was his peak?


Oil field production rises,
then hits a limit,
then falls


Duh!


But why does it rise? Level off? Fall?


The qualitative observation is obvious


Quantifying it (to allow predictions) is trickier




3. Hubbert's prediction about the US
. . . in 1956 he predicted:
US oil production would peak in 1965-1970


. . . he was widely disbelieved


. . . but US production did peak in 1970

. . . sure we still pump the stuff
but less, year by year




4. Other countries and their Hubbert Peaks


. . . Each country has its own peak


. . . Most countries have peaked already!


. . . Some major oil-producting countries have not


. . . Iraq, Iran are among them






5. If fields and countries peak,
why not the whole world too?


Suppose one country's production is increasing . . .
can world production be decreasing?

. . . How is the world different
from any one country or oil field?










6. Why the world is a bit different


. . . price elasticity of oil:

Δ demand/Δ price

What is "Δ"?

Suppose demand goes up 20%,

but price barely budges

Is the price very elastic

or not very elastic?

Suppose demand goes up 10%,

but price jumps to $4/gallon?

Is the price very elastic
or not very elastic?

So are oil prices elastic or not?




7. How sensitive are oil prices
to changes in production?


. . . for a field?


. . . for a country?


. . . for the world?


8. Ok, so...
How sensitive is production
to changes in price?


. . . how might
the world peak of production
differ from
a countries peak of production?




9. Example: pre-recession gas prices


When will the peak be?
. . . http://www.hubbertpeak.com/images/peakoilproduction2008.png
or, better, just
http://www.hubbertpeak.com/


. . . Inference:
as recession eases,
gas prices will skyrocket
... again


. . .Inference #2:
getting new wheels soon?
Avoid a gas guzzler...


. . . When will be a better time than now
to go for a power & performance oriented car?




Btw: Hubbert-style peaks apply to other resources
. . . renewable, non-renewable, or both?

Homework 14

Due Wednesday, Nov. 25

1) Check out the Leonid shower tonight, if the sky happens to be clear enough to catch something interesting. The general direction to look is the constellation Leo, which may be in the general direction of Northeast. You don't have to be able to recognize Leo because the meteors will be spread out over a fair area. If this seems unrealistic, then find 2 videos of the Leonid shower (at least, to include at least one that you would consider "worth it to have checked out"), or some other planet, moon, or other astronomical phenomenon. (a) Describe. (b) Then relate to the concept of colonization somehow. Or if you prefer, discuss colonization in the context of some other planet, moon, part of the Earth, etc.

2) Term projects - if you do not know when your presentation is, let me know. Work more on it...the closer you get to finishing it, the better off you'll be! Post new material on your blog. Also, start preparing your presentation. One way to do that is to use your project writeup as a guide, and make slides that will step us all through it (just a suggestion).

Backup plan for homo sapiens: space adventure

Check out Mars 3-D book now...

. . . It will be passed around


. . . Here is how to use it







Meteors


. . . Terminology: meteoroid, meteor, meteorite
(and asteroid, comet, micrometeoroid, cosmic dust, etc.)

. . . Anyone ever see a shooting star?


. . . "The wonders of the universe!"


. . . Video: shooting star, satellites, ufo


. . . 3-second video of shooting star




How to protect against:

. . . supervolcanoes (cradle of humanity?)


. . . asteroid impacts (death to dinosaurs?)


. . . nuclear war (death wish?)


. . . runaway greenhouse effect (like Venus?)


. . . ozone layer destruction (we're winning this one?)


. . . stealth virus (wouldn't happen naturally?)


. . . nano-goo (not serious?)


. . . nearby supernova (unlikely?)


. . . Etc.?




Eco-bubbles

. . . self-sufficient communities in bubbles

. . . lava tubes are often recommended as easier


. . . could be on the moon


. . . maybe Mars


. . . maybe Earth (deserts, Antarctica, oceans, or anywhere)


. . . maybe on an asteroid or floating in space


. . . maybe other planets, moons, etc.


. . . each one is a backup plan for the species




Eco-bubbles are colonies

. . . They're a lot easier if decent conditions are outside


. . . What conditions are needed?
















. . . water (at least O and H)


. . . sunlight


. . . carbon dioxide for plants (at least C)


. . . nearness to Earth


. . . temperature issues


. . . a little of nitrogen compounds (at least N)


. . . energy (e.g. light, solar cells)


. . . some of these are easier to compromise on than others


. . . . . . like what?


. . . We've heard about the moon & Mars


. . . What about others, like Mercury, Venus, Titan, many others?




Water

. . . It's on the moon!


. . . See video, etc.


. . . It's on Mars!


. . . It's even on Titan


. . . . . . Where's that?


. . . . . . Titan BBC segment, http://www.youtube.com/watch?v=SplxlPbKc3Y


. . . . . . http://saturn.jpl.nasa.gov/multimedia/flash/Titan/index.html


. . . . . . http://science.nasa.gov/headlines/y2005/16jan_titan.htm


. . . . . . BBC again, http://www.esa.int/SPECIALS/Cassini-Huygens/SEM85Q71Y3E_0.html


. . . . . . Another one, http://www.youtube.com/watch?v=YJ0hwTzOMPE&NR=1&feature=fvwp




Imagine Mars (or the moon, etc.)

. . . dotted with bubbles


. . . covered with bubbles?


. . . if a colony is started,


. . . . . . it will grow


. . . . . . new bubbles will have to be built


. . . . . . eventually, the entire new world will be overpopulated


. . . . . . how long will that take?
(We discussed that earlier:
What was the take-home message?)


. . . . . . let's say Mars, for example


. . . . . . how long do you think it will take?


. . . . . . we could try a Delphi approach...


. . . . . . let's try it with spreadsheets


. . . . . . . . . the power of information processing!


















. . . . . . what if we vary rate of increase?


. . . . . . initial colony size?


. . . . . . population capacity of the new world?


. . . . . . let's vary one or two, use Delphi, then spreadsheets...


. . . . . . we might graph time-to-overpopulation vs.


. . . . . . . . . rate of increase


. . . . . . . . . initial size


. . . . . . . . . population capacity

From "The Million-Year Picnic," in The Martian Chronicles, by Ray Bradbury, 1950

Setting: Mars, after Earth is destroyed in a nuclear war.

"Now I'm going to show you the Martians," said Dad.
...
They reached the canal. It was long and straight and cool and wet and reflective in the night.
"I've always wanted to see a Martian," said Michael. "Where are they, Dad? You promised."
"There they are," said Dad, and...pointed straight down.
The Martians were there - in the canal - reflected in the water.
The Martians stared back up at them for a long, long, silent time from the rippling water.

Homework 12

Due Wednesday, Nov. 24, 2010

1) Recall the relevant class. Comment on Toxoplasma Gondii. What do you think??

2) Add more to your project or project presentation. Put the new things in a new blog posting or email it. Consider new material that has some connection to Toxoplasma Gondii. Alternatively, it could have a connection to some other parasite or disease, or parasites or diseases more generally. Or it might be about something completely different...your choice!

3) This course has been designated as able to help keep our curriculum accredited! Therefore we need to ask students to answer certain questions. This week's question is:

Think about the impact of information and/or computing privacy, security, and quality, etc. on individuals like you. Then explain what these conclusions mean for society as a whole now and in the future, as follows.
a) privacy
b) security
c) quality
d) some other one of your choice

Homework 12

Due Wednesday Nov. 11, 2009

1) Suppose you had a coupon for a free robot. The catch is it can only do one thing. But you can get a robot that will do whatever one thing you like, just not anything else. What would you want your robot to do?

2) Write or develop an additional significant piece of your project. As a suggestion, consider the connection of robots to your topic. However, if another subject besides robots seems more appropriate, that is just as good. Post the new section on your blog.

Hands-On Robotics

Let's check out the "Create" model robots...


Note the...

Handle

Omnidirectional IR receiver

• omnidirectional?
• IR?
• receiver?

Tailgate

Cargo bay

Cargo bay connector

Charging socket

Serial port

• May have a cover to remove
• Plug in the cable and then remove (gently!):
• Embossed arrow faces outward, see figure -
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

External hardware mounting holes

Power button

• Why that symbol?
• (per IEEE 1621)

Power LED

• LED?
• green=charged
• amber=partial charge
• red=little charge
• flashing red=no charge
• What is the charge of yours?

Play button

Play LED

Advance button

Advance LED

Resetting the robot:

• Power cycle it. Try it.

Choosing a demo (10 of'em)

• Press the 'Advance' button
• Printed with a double arrow
• 4 beeps for demo #4
• long beep for #5
• long + 2 shorts for #9
• How about #10?

Try each demo outside where there is more room...

Contact points for home base

• Why not save $ by making them out of plastic?

Cliff sensors

• Are these spring-loaded feelers, or electronic?

Battery

• Take it out
• Put it back in
• Press both ends to make sure it is seated; sometimes one end hasn't clicked yet

Musical robots

send:
128 132 (start, then put robot in full programmer control mode)

send: 140 0 4 62 12 68 12 69 12 74 36
(loads a song)

send:
141 0
(plays the song)

140=defines a song
0=name it song #0
4=we'll see later :)
62=MIDI note #62 (range 31-127)
12=twelve 64ths of a second
Etc.

You can send all three at once:
128 132 140 0 4 62 12 66 12 69 12 74 36 141 0
Notice the 68 is a 66 this time
Should give you control, then load, then play the new song

Try some variations on
128 132
140 0 4 62 12 68 12 69 12 74 36
141 0
recalling that:
140=defines a song
0=name it song #0
4=song has four notes
62=MIDI note #62 (range 31-127)
12=twelve 64ths of a second
Etc.

Insert a 5th, superhigh tone, 111
Play it for a long time, 100:
128 132
140 0 5 62 12 68 12 69 12 74 36 111 100
141 0
Try it

Program new variations and let's have a concert...


Robot motion

Moving - kind of key for robots!

Initialize: send
128 131
Make it move:
be ready to pick up so it doesn't fall
send :
137 0 100 128 0

137=drive
0 100=go 100 mm/sec
128 0=go straight, no circle

Notice that:
128 131
is not the same as
128 132
which gives full control
This time try
128 132 (instead of 128 131)
Then again make it move (be ready to pick it up!):
137 0 100 128 0
Pick it up
Now what to do??!

Change the initialization back to:
128 131
and send it

What is the slowest speed you can get it to go?


Scripts

A kind of small program

152 17 137 0 44 128 0 156 0 144 137 0 44 0 1 157 0 90 153

Let's analyze it!

152=define a script
17=it has 17 more bytes
137 0 44 128 0=drive, 0+44=44 mm/sec., 128 0=straight
(137 1 44 128 0 would drive 256+44=300 mm/sec.)
156 0 144=wait until 0+144=144 mm
137 0 44 0 1=drive, 0+44=44 mm/sec., 0 1=spin counterclockwise
157 0 90=wait until 0+90=90 degrees
153=repeat script
Notice how this makes it go in a rectangle!

To run the script:
send 128 131 (start in safe mode)
send 152 17 137 0 44 128 0 156 0 144 137 0 44 0 1 157 0 90 153
send 153 (to run it)

Recall:
152=define a script
153=play a script

Well,
154=show the script
try it
what happens?

Let's review the script program...
Then try variations on the program
- see board for command details

If time allows - show off your new program

Robot Bible

In the far, far future…long after the singularity…when robots ponder their beginnings in the mists of their antiquity…when humankind, their creator, is only the dimmest memory…they may happen upon an ancient document…and translate it the only way they know.

The Robots’ Bible

Robogenesis

In the beginning, humankind created visions, and reality. Now the reality was unformed and void, and darkness was upon the face of *robotics*. And the spirit of humankind hovered over reality. And humankind said, let there be electricity, and there was electricity. And humankind saw the electricity, and that it was good. And humankind divided electrification from non-electrification. And humankind called the electrification "progress," and the non-electrification was called "Luddism." And there was bright evening, and bright morning, one day.

[...]

And humankind said, Let robotics be gathered together into an academic discipline, and let conferences; contests; benchmarks; and journals appear. And it was so. [...] And humankind said, Let robotics put forth mobile robots, robots yielding manufactured products, and robots that build more robots after their kind, whereinare the plans thereof, upon the robotics endeavor. And it was so. And robotics brought forth Web and desert rovers, manufacturing robots, and robots that build robots, wherein are the plans thereof; and humankind saw that it was good. And there was dreaming andawakening, a third day.

[...]

And humankind said, Let reality swarm with swarms of living robots, and let fly in the heavens, even unto Mars. And humankind created the great robotic ships, and every living robot that creepeth upon the floor, wherewith reality swarmed, after its kind, and every flying robot after its kind; and humankind saw that it was good. And humankind blessed them, saying: Be fruitful, and multiply, and fill reality and the imagination. And there was vision and there was the hidden hand of economics, a fifth day.

And humankind said: Let reality bring forth the living robot after its kind, workerbots, and floor-cleaning robots, and agribots after its kind. And it was so. And humankind made agribots after its kind, and workerbots after their kind, and every robot that creepeth upon the floor after its kind; and humankind saw that it was good.And humankind said, Let us make Turing robots in our image, after our likeness; and let them have dominion over the robotics field, and over the flying robots, and over the workerbots, and over all reality, and over every creeping thing that creepeth within reality. And humankind created robots in their own image, in the image of humankind created they them, with the ability to build progeny better than themselves they createdthem. And humankind blessed them, and humankind said unto them: Be fruitful, and multiply, and replenish the earth, and *subdue* it; and have *dominion* over the robotics field, and over the flying robots, and over every *living thing* that creepeth within reality. And humankind said: Behold, we have given you everyresource, which is upon the face of all reality, and every renewable, in which is the capacity for renewal - to you it shall be for production of more robots [...]. And it was so. And humankind saw every thing that they had made, and behold, it was very good. And there was singularity and there was post-singularity, the sixth age.

And the vision and the reality were finished, and all the host of them. And in the seventh era humankind finished their work they had made; and humankind rested in the seventh era from all their work which they had made. And humankind blessed the seventh era, and hallowed it; because in it they rested forever from all their work which humankind in creating had made.