Steve Walker wrote:
But none of that reverses the simple physical fact that
cooking/heating/baking/toasting will all use less energy by using a high
power for a short time than using lower power for a longer period due to
heat loss - nop matter how good the insulation.

Funnily enough, my microwave cooks food quicker than my gas oven, and with a
lower thermal input. Probably cheaper too, despite electricity costing
4x the price of gas per kWh.

It's not the power that counts, it's what you do with it.

Theo