Emily Kwong

They are the end result of humankind's enduring ambition to harness the power of the sun.

These scientists at Bell Labs back in the 1950s used the photovoltaic effect.

This is Jenny Heinzen, master electrician and the curriculum director at the Midwest Renewable Energy Association.

And she went full teacher mode in explaining to me how this photovoltaic effect turns the energy of the sun into an electric current.

So first, you need a material.

And it was Bell Laboratories in New Jersey that figured out you could use strips of silicon, the same stuff found in sand.

Silicon ended up being such an efficient and scalable material that it is what modern solar panels are made out of.

So basically the solar panel has a positive side and a negative side.

It's designed that way.

And the positive side is what absorbs the sunlight.

The sun's energy travels as photons.

Those photons, when they hit the solar panel,

They knock electrons free.

So then there's all these free electrons which then travel through the solar panel to the negative side.

And the flow of electrons, as we know, is electricity.

And this process is happening across hundreds of cells on any given solar installation.

Of course, you need a device to accept these electrons.

A lot of people use solar inverters.

These are magic boxes that convert that direct current into an alternate current.

So if you need more electricity, it pulls from the utility.