The cooking pots that we use now have flat bottoms. These pots absorb certain amount of heat energy from the heat source from the bottom. This heat in turn is conducted to the water in the pot. This takes a certain amount of time to boil the water.

Change the flat bottom of the pot to a corrugated bottom as shown. This will increase the surface area exposed to the heat source. This will increase the amount of heat absorbed by the same heat source. Also the corrugated bottom will increase the surface area that transfers the heat to the water in the pot.

With the corrugated bottom cooking pot, the same amount of water, in the same size pot, on the same source of heat, will boil quicker compared to the flat bottom pot resulting in savings of energy.