Hello and welcome to Business Daily. I'm Justin Rowlatt.

And you're listening to the latest in our Elemental Economics series

where we look at the role of the chemical elements in the world economy.

And for this program, I've been traveling.

You won't be surprised. You're going to San Francisco.

You won't be surprised to hear that San Francisco was the birthplace of a new high-tech industry,

but the people who first recognized the potential of this one weren't the spectacle techno nerds.

They were hippies fleeing the swinging city in the early 70s

to grow illicit marijuana in communes up in the hills.

Poor Lung, these executives at Arco Solar,

was like the first company down in L.A.

These guys flew up in Learjets with business suits

in this hippie general store in Willets.

And they came in and it just stuck out like sore thumbs.

We want to know why all of our solar panels are selling in Willits.

What the hell's going on?

But as we'll discover, it would take decades of improvements

and the intervention of some very surprising fellow travelers

before this industry would really take off.

What we're able to do now with some of the investments we've made is to be able to say to the homeowner within seconds,

we've already looked at your roof from the satellite image, here's a picture of what this will look like,

and here's exactly how much money you're going to be paying us monthly.

...