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How to Charge Your Cellphone Using Wasted Heat

Posted by ScuttleMonkey on from the diy-and-try-not-to-burn-the-house-down dept.

Ilya writes "Companies such as BMW are investing in Thermoelectric Generators to make their cars more efficient by replacing the alternator. Thermoelectric Generators convert wasted heat from the engine into electrical power. This green instructable shows how you can use the same technology right now at home to harvest expelled heat from home appliances to charge your cellphone and other gadgets. Also features a lego racer powered by the roaring flames of a tea candle."

4 of 214 comments (clear)

  1. Sipping From a Firehose by lobiusmoop · · Score: 4, Informative

    Given that the average American consumes 13,500KWh per year, getting a couple of Watt-hours into your phone from wasted heat instead of the grid isn't going to make a damn bit of difference.

    --
    "I bless every day that I continue to live, for every day is pure profit."
    1. Re:Sipping From a Firehose by DirtyUncleRon69 · · Score: 4, Informative

      I worked at Toyota for a while we have been talking about this for at least a year. The technology has been around for a long time, but we usually call them thermocouples. It's exactly the same concept, except they need to be much larger, and have a much higher temperature differential to be useful. The main problem is the size and weight. The weight is significant when you're looking to reduce mass to improve fuel economy, and obviously it adds cost to the vehicle.

      As for extracted heat reducing the efficiency of the engine, after heat leaves the cylinder head, unless it is used to do work (as in a turbocharger) it is waste.

      --
      They say, "Evil prevails when good men fail to act." What they ought to say is, "Evil prevails."
    2. Re:Sipping From a Firehose by lobiusmoop · · Score: 4, Informative

      OK fine I will run the numbers for you:
      One day a month is statistically significant at around 3%.

      My cellphone battery is 3.V, 750mAh, or about 3Watt-hours capacity. Emptying/charging it every week of the year gives about 150Wh consumption then, compared to 13,500,000Wh an American uses a year, or about 0.001%. This is statistically insignificant.

      Hopefully that makes things a bit clearer for you.

      --
      "I bless every day that I continue to live, for every day is pure profit."
  2. Not news, not new technology! by kheldan · · Score: 4, Informative

    Peltier Junctions are really old news, they're not very efficient at all, they don't last forever, and they're not particularly cheap. TFA doesn't have anything new to say or any links that have anything new to say. Mod the entire post down to -1, Useless post and move on.

    --
    Are YOU using the TOOL, or is the TOOL using YOU? Think about it!