LED science fair question

[hsp]

We are doing the old fruit cell battery experiment. Our fruit is generating 1.54V, so how is it possible that it lights our 2.4V, 20mA LED? Of course, it is not emitting a bright light, but it is definitely powering the little red bulb. Please help this mama!

[Sebi]

Simply build two fruit-cells and connect serial for 3V output voltage, or You can build a step-up converter: that widely used in solar-cell-garden-lamps.