[Stoves] Insulated pots -- retained heat cooking

[Crispin Pemberton-Pigott]

Dear Edward

>It would seem a crock pot of such design
>with embedded electrical element could
>with potentially surprisingly low energy
>rate of usage achieve boiling points and
>automatically switch on or off as desired
>and maintain temperatures as desired for
>prolonged cooking effect.

Well that is a very good description of an efficient cooker.  An electric
kettle, a coal stove for space heating and an electric frying pan with a
cover on are all really efficient.  Water heaters are very good.

Something that is worth considering is how the electricity is produced.  If
the efficiency of the power generation is 35% from coal, the transmission
efficiency is 75%, and the distribution efficiency 90%, you can see that the
nest improvement is to use local heat sources for heat applications - like
cooking.

I have been wondering about the total pollution from a really modern coal
plant compared with the total pollution from a well made small stove - for
cooking.

If you use an electric stove with an efficiency of 50%, only 12% of the
coal's heat reaches the water in the pot.  No better than an open fire.  For
space heating, a local fire is far better than an electric heater!  Perhaps
it is 7 times more efficient.

Best regards
Crispin in Maputo