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30 years ago I had a credit card calculator powered by a solar panel. Ideal pairing. Viewable screen in direct sunlight too thinking about it.

Renaud 6y ago
Calculators need mere microwatts of power to function. A very basic laptop is in the tens of watts. A difference of many orders of magnitude that you can't compensate by the size of solar panel on a small device.
- supermatt 6y ago
  > A very basic laptop is in the tens of watts The latest version device in question (the OLPC) is ~5W under normal usage and less than 1W when idle. Im not sure about an integrated solar panel - im not sure i would want to keep my laptop exposed to the sun - but i was able to keep a 2015 macbook charged with a small solar panel while travelling (approx 4 hours a day of heavy usage). Obv depends on time of year, location, weather, etc.
  - AshamedCaptain 6y ago
    But even 1W is several orders of magnitude greater than the average LCD calculator.
    - deleted 6y ago
      [deleted]
numpad0 6y ago
It’s interesting that electronic calculators are basically the only type of devices ever to have successfully powered by integral solar panels. There are some electronic price tag products, wireless keyboards, decorative keychain tags, etc. that could work on solar only, but even those are rare. e: Forgot digital wristwatches. They seem to work fine.
- AshamedCaptain 6y ago
  And it's pretty simple to figure out why it's so for electronic calculators. I had one of these, a modern-ish one though, except that the solar panel was defective and never actually worked. I only noticed after 3 years of use. That's how much the builtin _half-discharged_ coin battery would last... and how useless the solar panel actually is... I would even guess they only put in the solar panel for the look. You could probably power such a calculator from ambient radiowaves, using a galena crystal...
  - frosted-flakes 6y ago
    A lot of basic solar-powered calculators don't have batteries at all. Covering the solar panel will shut it off.
    - kn0where 6y ago
      And a lot of cheap calculators don’t even have real solar cells: https://youtu.be/uLTDuGhqE2w https://youtu.be/uLTDuGhqE2w
    - AshamedCaptain 6y ago
      Yeah, what I mean (and has been better put elsewhere) is that the consumption of your average calculator is so low as to be practically negligible (<1mW?), otherwise capable of running for years on a depleted battery. Which is why they may work from such a small solar panel, but at the same time it says nothing about the solar panel itself.
- csharptwdec19 6y ago
  > wireless keyboards I really like the Logitech K700 solar keyboards, with two caveats: - In a couple of mine, the included battery seems to have lost the ability to keep a charge well before you would expect (i.e. a year). This is a bit of an annoyance in that it is a rechargable button cell, not your run of the mill AA/AAA sized NIMH/Lithium bit. - The build quality on these as far as sturdiness/etc isn't great. And if it ever gets 'flexed' too much, you wind up with broken traces internally, leading to issues where the juice doesn't flow one way or another unless you flex it back in the right way. I love them in the office, but at home they just don't handle the use of clumsy roommates.

Renaud 6y ago

Calculators need mere microwatts of power to function. A very basic laptop is in the tens of watts. A difference of many orders of magnitude that you can't compensate by the size of solar panel on a small device.

supermatt 6y ago
> A very basic laptop is in the tens of watts The latest version device in question (the OLPC) is ~5W under normal usage and less than 1W when idle. Im not sure about an integrated solar panel - im not sure i would want to keep my laptop exposed to the sun - but i was able to keep a 2015 macbook charged with a small solar panel while travelling (approx 4 hours a day of heavy usage). Obv depends on time of year, location, weather, etc.
- AshamedCaptain 6y ago
  But even 1W is several orders of magnitude greater than the average LCD calculator.
  - deleted 6y ago
    [deleted]

numpad0 6y ago

It’s interesting that electronic calculators are basically the only type of devices ever to have successfully powered by integral solar panels. There are some electronic price tag products, wireless keyboards, decorative keychain tags, etc. that could work on solar only, but even those are rare. e: Forgot digital wristwatches. They seem to work fine.

AshamedCaptain 6y ago
And it's pretty simple to figure out why it's so for electronic calculators. I had one of these, a modern-ish one though, except that the solar panel was defective and never actually worked. I only noticed after 3 years of use. That's how much the builtin _half-discharged_ coin battery would last... and how useless the solar panel actually is... I would even guess they only put in the solar panel for the look. You could probably power such a calculator from ambient radiowaves, using a galena crystal...
- frosted-flakes 6y ago
  A lot of basic solar-powered calculators don't have batteries at all. Covering the solar panel will shut it off.
  - kn0where 6y ago
    And a lot of cheap calculators don’t even have real solar cells: https://youtu.be/uLTDuGhqE2w https://youtu.be/uLTDuGhqE2w
  - AshamedCaptain 6y ago
    Yeah, what I mean (and has been better put elsewhere) is that the consumption of your average calculator is so low as to be practically negligible (<1mW?), otherwise capable of running for years on a depleted battery. Which is why they may work from such a small solar panel, but at the same time it says nothing about the solar panel itself.
csharptwdec19 6y ago
> wireless keyboards I really like the Logitech K700 solar keyboards, with two caveats: - In a couple of mine, the included battery seems to have lost the ability to keep a charge well before you would expect (i.e. a year). This is a bit of an annoyance in that it is a rechargable button cell, not your run of the mill AA/AAA sized NIMH/Lithium bit. - The build quality on these as far as sturdiness/etc isn't great. And if it ever gets 'flexed' too much, you wind up with broken traces internally, leading to issues where the juice doesn't flow one way or another unless you flex it back in the right way. I love them in the office, but at home they just don't handle the use of clumsy roommates.