Question: How much energy does a single half-lemon produce? And for How Long :)

Petra Cameron answered on 18 Jan 2017:

The lemon is not really producing the energy! The battery is created when a piece of zinc and a piece of copper are put into the lemon and connected together with a piece of wire. The juice of the lemon acts as an ‘electrolyte’ that can conduct charge and so it completes the cell. Electricity is created as the zinc is oxidised and the copper is reduced, an ideal single copper/zinc cell gives a voltage of 1.1 V when the copper and zinc are first connected. As a current flows the mass of zinc metal decreases and the mass of copper metal increases. After a short time there will be no driving force for the reaction and the battery will be dead!