Why must an Energy pyramid have more producers than consumers ?

Answer 1

At each trophic level some energy is used in the metabolism of the organisms (and other losses from the system) and some is incorporated into the bodies of the organisms at that level. Only the energy incorporated into the bodies is available as food to the next level. Since the producers are the bottom level, they must have more energy than the higher levels because of this loss.

Answer 2

It is like if your mom puts food in the refrigerator and all the kids in the family try to eat it even faster than she can refill it.

If energy amount isn't at least as much as people want to use then the consumers are out of luck.

Answer 3

It doesn't have to. In some, admittedly unusual,
communities the biomass of consumers at any
given time is greater than the mass of producers.
To make this possible the producers have to
multiply faster than the consumers, so that the
rate of production exceeds the rate of consumption.

Answer 4

Because some energy is always lost (wasted) in the conversion (as one moves up the pramid).