[Stoves] solar cooker response (changing thread name)

[Andrew Heggie]

On 12 June 2017 at 20:35, Crispin Pemberton-Pigott
<crispinpigott at outlook.com> wrote:

> There are two kinds of induction heater that I have seen at the bottom of the market: single and double plates. The double one has a high power (often 1000-1100 W) and a 700 W one. Both plates on is about ten amps.

Mine was the cheapest I could find locally and is rated at 2100W but
you seldom use high power, indeed my first few tries I burned food
when frying

https://www.amazon.co.uk/Tefal-Everyday-Induction-IH201840-Ceramic/dp/B00ER445UQ
>
> ‎The efficiency of the single plate units is 88-92%. That is much higher than an electric hot plate.

Yes and because it heats the pan directly there is no loss involved in
heating the hob, it does have the parasitic load of a cooling fan for
the electronics.

>
> So running the big plate for 30 minutes is 0.5 kWh. 500 Watt-hours. That is roughly a quarter of a regular car battery (1800 Wh). Is that reasonable?
>
> A large car battery can store about 4.8 kWh. It is fine for cooking, but not heating water.

Because it is fast you don't need it on for long, it also has various
sensors and a timer for things like gently heating milk, or porridge,
without it burning on the bottom of the pan.

If no one else has figures I will try and monitor its electricity
consumption, we tend to only have two for meals in this household and
I don't believe I have ever used it for more than 15 minutes at a
time.


A typical lead acid battery for a large diesel engined car is about
95Ah but you seriously damage it's life if you run the voltage below
11.5V, in practice as long as you have the capacity for the peak load
you would use a similar rated leisure battery but still only get about
24Ah from it, so about 0.5kWhr. This just about matches your
calculated usage.

My panels actually run at 300V and I would be looking to a lithium ion
storage battery if I were not grid connected.

I guess this sort of thing is for the remote but middling affluent
users rather than the sort of people we normally think would benefit
from improved stoves as the capital investment is large.