Collin’s Lab: Solar


Right now – energy radiating from the sun
is making me sweat Fortunately solar power technology allows
me to also use the sun’s energy to cool off a
bit. Your move … sun. Right – anyway! Solar panels were first used to power satellites
back in the 1950s, but since then they’ve become much more
efficient & widely used. A panel like this one converts light into
electricity using an array of solar or “photovoltaic”
cells – These cells are surprisingly simple devices
– quite similar to diodes. As you may recall, a diode uses two types
of silicon stacked together to allow electrical current to flow in a single
direction – negative-type silicon,
which has an excess of electrons and positive-type silicon
which has an excess of electron holes or vacancies waiting to be filled. Each photovoltaic cell uses a wide, flat layer
of p-type silicon covered by a thin layer of n-type silicon.
When light hits the surface of the cell, photons pass through the top layer
and hit the junction between the negative and positive layers. These photons knock electrons out of their
holes and toward the top layer of the cell…
while those empty holes are pushed toward the bottom. The positive layer of the cell is connected
to a single flat metal conductor, while the negative side is connected to thin
metal finger-like conductors which leave most of the surface exposed to
light. When we connect a circuit to these conductors,
electrons leave the negative layer and travel through the circuit
in order to reach those available holes down on the positive layer. All the while, more photons are knocking electrons
out of holes, and the cycle continues. Hmmm. Well that’s quite a bit different
from what a diode does, eh? I mean, a diode can’t generate electricity
or even respond to light … … or can it? Ok – here we have a bunch of silicon diodes, They’re the “small signal” type so they
have glass packages – which should allow light to pass directly
to the silicon. By wiring them all up in parallel and exposing
them to light We can see that in fact they do produce a
voltage of x.xx volts Wow. Ooh – and what about Light Emitting Diodes?
A row of 8 LEDs produces a voltage of x.xx These little tests won’t produce much current
– still it’s sort of bizarre that common LEDs
and diodes can act as solar cells. But I digress … A single photovoltaic cell can provide one
half of a volt. My panel here has … 2-4-6-8-10-12 cells – So at half a volt each that means it can provide
a total of 6 volts. It’s much more practical to use a solar
panel to charge a battery – and then use the battery to power … well,
whatever needs powering. In order to charge this 3.7V LiPo battery
from the panel, I’ll need a specialized charging circuit
… Which will manage the unstable output from
the panel to provide a steady charge to the battery. This small power boost circuit will convert
the battery’s 3.7 volts to a standard 5 volts
suitable for use with USB devices, microcontrollers and what have you …
In any case – even after understanding how it works,
the ability to convert light into electricity is still a bit mind blowing to me.
So go make something solar powered – but umm, don’t wear a black suit on the roof. Can I get a towel from somebody?

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100 thoughts on “Collin’s Lab: Solar”

  1. Xano Trevisan Kothe says:

    Finally! Collin's Lab!

  2. Kevin Carmical says:

    Great work! I wish he made a video weekly.   🙂

  3. Afrotechmods says:

    Best one yet!

  4. Lucas Zanella says:

    collin's lab video production is of the greatest quality

  5. Jeff Barr says:

    Excellent as always !

  6. SeiRruf Wilde says:

    I learned that LEDs can actually produce power here first, folks! Awesome haha That makes me wonder, do outdoor LED billboards take this into consideration? I'd imagine the back-feed of that much power being generated when the sun hits them, creating a problem.

  7. erehwyrevekool says:

    WOW …. refreshed from the sun!

  8. Rob Townsend says:

    I love Colin's Lab.  Keep them coming!

  9. PB P says:

    Very glad to see this series continuing.

  10. Gonzalo Ramirez says:

    Learn a lot! I have no idea about the diodes and leds can capture light and transform it in voltage. Thanks!

  11. Scott Tuohy says:

    Great explanation!

  12. PhattyMo says:

    2:55 ,yelling at my screen "Ahh,but they do!" 
    Also,some old transistors work too- find an old TO-3 case transistor,and pop the top off to expose the die to the light. 🙂

  13. Jon Mumbo says:

    This is awesome. Love Colin's lab. This this is the first one I've seen and very interesting indeed. Thank you!

  14. Blueberry Wiskus says:

    Yay Collin, I miss his videos…

  15. Blueberry Wiskus says:

    Yay Collin, I miss his videos…

  16. Noorquacker says:

    Hooray! More Collin Cunningham!

  17. Naheem Sheikh says:

    YOU ARE THE MAN. love the video

  18. Joven Albarida says:

    one that dislike the video are retarded

  19. Lakes57 says:

    Love the hat!, should have worn a white/cream suit though. 🙂

    For his next video Colin will be modeling a solar powered baseball cap with cooling fan. 🙂

  20. Zorn101 says:

    Do more please. This is a fantastic production.

  21. Rotchild says:

    Great production as always by Collin's Lab. I wish the uploading schedule was better though. I think that every two weeks would be a fair amount of time to film and edit the videos. There is roughly a month and a half between each of these videos. Keep it up Adafruit! 

  22. Thomas Records says:

    When I was younger, before there was one… I thought a solar powered flashlight was a good idea.  It does sound silly but it's on the market now.   Follow your dreams!  It's great to see that "Colin's lab" is still around.

  23. Marc Norris says:

    Thanks Collin!  I learn something new every time – Keep up the great work!

  24. Kent Dyer says:

    I always look forward to Collin's videos.  

  25. Christopher Kroupa says:

    Collin's Lab videos are probably my favorite thing on YouTube.

  26. Mike Black says:

    thank you!

  27. Francis Ziegler says:

    Collin Cunningham is a natural teacher–he always makes everything so simple.  God bless the Adafruit Gang. 

  28. coatduck says:

    You're back!
    This was my favorite series back on make, and you were the one that got me into electronics!

  29. Jorge Mario Zuleta says:

    What a beautiful video!

  30. Joseph Dawson says:

    More Colin!

  31. Smooooth says:


  32. Ryan Jensen says:

    It is bittersweet to see that Collin Cunningham is making videos again.
    They are definitely different than the videos he was making years ago.
    These new Adafruit videos seem watered down. They feel scripted, unlike the old videos which seemed geeky in an organic way.
    Nevertheless, I will continue to watch. Collin is better than no Collin.

  33. EvoRulz says:


  34. Brown Dog Gadgets says:

    Collin, as always, your labs are educational and entertaining.  More teachers should use your videos (like I used to), as they're typically all around better than than the ones supplied by curriculum makers.  Kudos galore!

  35. BecauseVideos says:

    I cant get enough of Collin's Lab

  36. Rouverius says:

    The raw output a small solar panel can be used in place of a light dependent resistor (LDR). Also, hooking a small panel to an amplifier or a voltage controlled oscillator creates some interest sounds. Allows you to hear sunlight.

  37. J S says:

    dont wear a black suit..on the roof lmaooo

  38. 13th Human says:

    Wow! Awesome! I have been reading lots of books about solar and… I just understand the basic concept by viewing this 5.25 minutes video! Cool! Keep it up! 🙂

  39. Innasoul Φ Music Φ says:

    Colin's back!!

  40. Jay D. Anderson says:

    Great video — Collin, you have a knack for making something complex very understandable. I have learned a lot from you — A LOT!   Thanks.

  41. Evansmustard says:

    Holy crap i used to watch colins lab all the time and i just thought i would revisit some of his old videos and somehow slipped under my radar and made a small series! Looks like he is gone again though…

  42. john doe says:

    Please make more collins labs! these are great!

  43. Rafael Scott says:

    AWESOME! More Collin's Lab, please!

  44. Justin Hall says:

    Mistake: "They do prove that diodes and LEDs work in a similar way… but I digress."  I think you meant diodes and solar cells…

    But I digress.

  45. Dunjii says:

    More of Collin, please. He's very entertaining and informative.

  46. HK Park says:

    really amusing

  47. ElecTroMan DIY AMPLIFIER says:

    I never notice that before zener diode and LED diode are producing small amount of electricity! wow

  48. Larry Kaufhold says:

    If LEDs read light coming in – can your monitor be a camera? I believe The LCDs have LEDs behind the liquid crystal. If so aren't all TV's, watches and cell phones just cameras? Is big brother watching you?

  49. Maxim Zodal says:

    OK, I've gone through all your videos and I'm ready for MORE!  Great videos.

  50. Michael says:

    Where did that show go? 
    The show with that adabot is stupid.

  51. Practically Atargaryen says:

    Collin, sweet vids.

  52. Harry Merzin says:

    do the electrons ever reset to the junction between the positive and negative layers?? or once they get nocked out once, they're done…

  53. My first name My last name says:


  54. FirstInstruMentalist says:

    Alton Brown+Dwight Schrute.

  55. Keith Green says:

    Would a magnifying glass be able to magnify the results of a solar cell? Where are the bottlenecks in the current design?

  56. Ty Luna says:

    What does he use in this video, (like how did he connect everything)

  57. Orlando Selenu says:

    Very interesting and very useful! Thanks 🙂

  58. Nick Farrow says:

    How cool would it be if lights of the future suck up energy in the day and produce light at night.

  59. Zed says:

    You're move sun

  60. chaseswafford says:

    Simple, Basic, Quick and to the Point. Ty

  61. phuturephunk says:

    Nice frame of lower Manhattan and Jersey City at the end there. Great video!

  62. Benjamin Lord says:

    I dig Collin's Lab don't stop doing it bro.

  63. Luigi Pizzolito says:

    what is the song in the intro?

  64. Scott .T says:

    great video don't stop making Collins lab

  65. Ted Van Matje says:

    why has collin not been enrolled to work in the startrek movies yet? i could just imagine the a discussion between him, scotty and spock 🙂
    thanks for posting!

  66. Sience Tech says:

    great thks

  67. chabka34 says:

    omg this guy is my favorite

  68. Taavet says:

    I always notice the way he nods every now and then and kinda squeezes the lips or something like that.

  69. R4zE says:

    "Your move, Sun."
    Solar Flare

  70. cncz says:

    Can the panel run out of electrons?

  71. Severīns Dudeničs says:

    where i can listen to your music?

  72. Tomas Sab says:

    awesome style

  73. Ahmed Hameed says:

    WAAAAAAAW , I love your work Collins 🙂

  74. warden says:

    Colin's lab reminds me of pokemon trainer tips.

  75. James Cullins says:

    You very funny ! which make it fun to watch.

  76. FraznoFire says:

    "Your move sun" lol

  77. Bill says:

    Collin is burnt. I love it.

  78. Colin Godsey says:

    these are really good. make moar!

  79. AJ Pro says:

    very enjoy watching this….he is so funny, more pls…

  80. walperstyle says:

    Note: Much of the material in solar panels comes from mined goods, of which are powered by fossil fuels. If you are voting in a politician that is for a Carbon tax, you are actually helping drive up the cost of solar technology. Please stop!

  81. Pedro Mano Fernandes says:

    Hey Collin, great video! I'm interested in doing it myself. Can you please list the materials/components used? Maybe with links to Adafruit store. Thanks.

  82. Tracti0n says:

    "Your move Sun"
    Sun intensifies

  83. TrueDesire Elements says:

    I LOVE "Collin's Lab", It's the best EVER!!!!!!!

  84. Jonathan F. Jackson 2nd says:


  85. Polar702bear says:

    Collin, shave your head and grow a beard. You'll look like you can really rock the look.

  86. Crazy Couple says:

    Mate you are awesome

  87. oceanblue christnineangel says:

    You do the job call "Steve Job " you so awesome .
    big thanks to all your lectures
    and your teaching so fun .

  88. Erik Burman says:

    The hat is a good look for you.

  89. Bob Wareham says:

    I love your videos there very good just wish you had your own youtube channel it would be cool

  90. Octillic 2 says:


  91. Bryan St.Martin says:

    WooHoo! We have an excess of holes! And next you're going to tell me that the holes flow from positive to negative, right?

  92. MARCELO JAVIER says:


  93. Jayaon Natoc says:

    make a music instrumental… like arduino drum with you own code,, that will be cool… i wish you can make one….

  94. Domo Brah says:

    Only Collin could make me laugh in the first 3 seconds 😂😂😂

  95. RobMacKendrick says:

    Just the music, man. This was the best series ever.

  96. Chrismofer says:

    I'm so glad this videos are still around. just as watchable, well paced and informative as 2014

  97. Engr Noor Salam says:

    Great videos ever I have seen and the presentation style is awesome

  98. Doug Stanton says:

    Where are you Mr. Cunningham? These tech sites are getting views because of you sir. Please come back to YT.

  99. Teslafan says:

    Quality video made by quality man. You are my favorite electronics guy.

    But one video is missing. ie., How computers work.. Would you please make it for us..? Based on these points..>> memory, CPU, input and output. I will be very grateful if you make one.

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