7Energy consumptionTo save energy, you should . .- use only cooking and frying utensils with smooth,flat bottoms.- place pots and pans in position before switchingon the cooking zone.- wherever possible, cover pots and pans with a lid.- switch off the cooking zone a few minutes beforethe end of the cooking time, in order to make useof the residual heat.- use the residual heat of the cooking zones forkeeping food warm or for melting.- position pots and pans centrally on the cookingzones.Saucepans and frying pansSaucepans and frying pans should not be smaller thanthe cooking zone, and preferably not more than 10-15mm larger than the diameter of the cooking zone.Always use cooking and frying utensils with smooth,flat bottoms.The bottoms should always be clean and dry. Cookwith a lid in place.Check that the bases of utensils are smooth andundamaged; bases with burrs and sharp edges willscratch the ceramic glass surface.To avoid scratching or damaging the ceramic cookingsurface, pots and pans should be moved on the plateby lifting them, and not by sliding.Utensils with aluminium and copper bases can leavebehind metallic discolorations which can only beremoved with difficulty or sometimes not at all.ii