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?), othe

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.