I have a stake in these, so I'll have a disclaimer there.

As of 2007, there are only about 4 square miles.

(Laughter)

I've got data to back up all these assertions, by the way.

This makes a Hydrogen economy unlikely.

We can do the same for geothermal energy and solar power.

I love renewables. But I'm also pro arithmetic. (Laughter)

China leads their explosive growth and their plummeting cost.

And the technology that we settled on as an ideal partner for the Seawater Greenhouse is concentrated solar power, which uses solar tracking mirrors to focus the sun's heat to create electricity.

(Laughter)

Went straight to the president.

For the first time, this year the cost of solar generated electricity is 50 percent that of diesel generated electricity in India 8.8 rupees versus 17 rupees.

This was from Nature magazine.

And in six months they can become solar engineers.

They're speaking to each other and actually becoming solar engineers.

So, about two and a half hours of the day we could collect with a stationary component.

Sunny as in the sun and sunshine.

I'm, first of all, renewable energy's biggest fan.

CA All right. So this is only one string to your energy bow.

pennsylvania's exercising leadership on solar power and wind power.

Yeah. I believe we don't really appreciate what we have, and I only speak for myself.

Two terawatt hours, it's roughly half what the U.S. solar industry produced last year.

There's massive P.V. arrays on the roofs as well as wind turbines.

He knows more about solar than anyone I know anywhere in the world guaranteed.

Those three women have trained 27 more women and solar electrified 100 villages in Afghanistan.

We're using energy we can harvest on our roofs, and also on the training pitches, which will be covered with large, flexible membranes, and we will see in the next years an industry coming up with flexible photovoltaics, giving the possibilities of shading against strong sun and producing electric energy in the same time.

And trust me, I've got a day job, I've got a lot of day jobs.

But better what is more important is that they would have to concentrate sunlight.

What if you combine the petals and the engine in the center?

In fact, every region of the country could do this.

The sun sends out light.

Likewise, with solar, especially here in California, we're discovering that the 80 solar farm schemes that are going forward want to basically bulldoze 1,000 square miles of southern California desert.

This has to be a bridge to the point where you can get to wind, to the point where you can get to solar, to the point where you can get to nuclear and hopefully you won't build the next nuclear plant on a beautiful seashore next to an earthquake fault.

(Music)

This optic was 22 feet long.

They were dependent on solar power and it was believed that they would be unable to survive without an energy source as abundant as the sun.

(Laughter) (Applause)

I love being around these big wind generators.

This is what we teach in the night schools.

On an average adjusted day, a solar cell because the sun's moving across the sky, the solar cell is going down with a sine wave function of performance at the off axis angles.

Did you see the glare?

MICHAEL We're losing the light!

Light years are about 63,000 astronomical units.

I won't say never because once it becames summer, they will be able to see the Sun, so, no sunlight, no day I guess you could say.

The output power of a one square meter solar panel is about one watt, so it is difficult to use solar power on a large scale at present.