5 ms·

A human has to refill the bottles.

• gkop 11y ago
  Another mechanical approach that is relatively cheap and doesn't require refilling bottles is to use a closed system of a hydraulic cylinder and two exposed freon tanks, one facing east and one facing west: http://www.motherearthnews.com/diy/solar-tracker-zmaz77ndzgoe.aspx http://www.motherearthnews.com/diy/solar-tracker-zmaz77ndzgo... These mechanical approaches are generally awesome because they hold up well in bad weather. If you wanted to go all out I don't see why you couldn't combine the gravity system and the freon system and track on 2 axes! (Anybody got a clever idea how to make one system or the other neatly handle the axis corresponding to the height of the sun?)
  • biot 11y ago
    What about an array of photodiodes like this: o o o o X o o o o This is in an enclosed box with a hole over the center. Here, "o" represents a photodiode and "X" represents the center of the hole. When the solar panel is pointed directly at the sun, the sun is at position X and no photodiode is lit up. As the sun changes position, eventually it will light up one of the photodiodes. That completes a circuit which uses power from the panel to drive a motor, which is attached to a worm gear and rotates the panel towards the sun. Eventually the sun will be pointed at the X position again which breaks the circuit and stops the rotation. Each diode completes a circuit, driving one or both motors (in the case of the corner diodes) rotating them appropriately. It'd be interesting as well to have some sort of mechanism which, when the panel receives power, keeps it locked in place. When the panel has no power for a period of time (ie: after sunset) the mechanism disengages and the panel falls back to its default position pointing towards sunrise.
    • gkop 11y ago
      Good ideas! I had in mind a purely mechanical mechanism that takes the linear motion of the hydraulic piston or the water clock and turns it into a parabolic movement. I'm a software guy and could not find such a mechanism easily on Google, though.
    • mapt 11y ago
      Finding vertical & finding north is not a problem, you can get that trivially in a tiny MEMS IMU if you don't want to do it manually, and from there determine the optimal path for solar tracking without added variables, supposing you have the timezone set by the distributor (or use a GPS for that at a few dollars a chip). The cost is in the rotating frame and the motors.
• justifier 11y ago
  i think analogous from your observation could be: fill water bottles once in the morning or additionally use mind, motor skills, and body, lose the free use of a hand, resources to wave a fan in front of your face all day;
  • glibgil 11y ago
    Or, humans use electronics and motors because it actually is more efficient than getting a human to do the work.
• cb18 11y ago
  "Gravity powered," not "fully automated." I think this is pretty clever.
  • glibgil 11y ago
    "It is 30 times less expensive than conventional motorized solar panel rotators" if you ignore the fact that getting a human to do something is super expensive.
• 2sk21 11y ago
  In a country like India, especially in the villages, there would mist likely be enough free labor to do something like this.
  • glibgil 11y ago
    Free labor? Slavery?