[Stoves] solar cooker response (changing thread name)

[Andrew Heggie]

On 12 June 2017 at 21:39, Crispin Pemberton-Pigott
<crispinpigott at outlook.com> wrote:
> Dear Andrew
>
> When we were looking at the claim that simmering a pot could produce an 'efficiency' and fuel consumption 'per litre simmered', Yixiang and I investigated induction cookers in the 1800-2100 W range. All were single plate, like a gas fired wok cooker. Some have six settings for power, down to 300 W.

Unfortunately this one only goes down to 450W in 9 steps but I see a
hay box as being complementary to it.
>
> The 88% efficient were marked C, the 90% were marked B and the 92% were rated A. That is a Chinese national rating system.

I cannot see a rating on mine, as most electrical goods on sale here
it is made in China.
>
> ‎In Canada there were, for a time, no powerful ones. All were under 1 kW.  It could easily be run on a 1 kW inverter. Given the coincidence  of the voltage being half and the power being half, I am wondering it the guts are same, just that it runs on a lower voltage. They are still rare in Canada except for expensive built-ins, 4 or 5 plate glass tops.

I'm guessing the electronics rectified from our 240V supply and then
the frequency for the induction reformed so it probably has a DC bus
if one were clever enough to know what to do.
>
> That is all an aside. What we measured was the direct heating of the water and it was a lot less than 90% efficient. The stability of the power consumption was excellent. Yixiang reported the efficiency in the 70's.  ‎It is possible that the pot itself has an effect of the efficiency of the induction. That is going to affect the battery life.

In the early days of playing with TLUD I did use the weight of water
evaporated by the dry weight of wood burned for my efficiency tests.

I can do so again for this if you suggest a protocol. I only have
kitchen scales.

Andrew