[SQUEAKING]
[RUSTLING]
[CLICKING]
JEFFREY GROSSMAN: Now, why does this matter?
I've got two Why This Matters today.
My first one is on a personal scale, smaller scale.
And then my next one is on a grid scale.
So this is called the little sun.
There's over a billion people who can't read at night,
because there's no access to electricity.
And of course, a lot of the studying that you could do
would be at night, right?
So this is a really cool program.
Why does this work?
This is solar cell.
But this wouldn't work, unless you could
store the electricity, right?
So I wanted to make you guys aware of the little sun.
I'll pass it around.
You just press this, and you can read at night, right?
This is already making a big difference
in millions of people's lives.
That doesn't happen, unless you've
got electrochemical energy storage, right?
And there's some stats up here.
25 billion liters of kerosene are
used to meet the basic lighting needs in a lot of these places.
That releases tremendous amounts of toxic fumes.
And you can make a huge difference, but you can't--
the same as cooking, right?
So wood fire cooking is a huge problem.
So the challenge is-- but you don't cook.
If you have a solar cooker, that's
great, except that most people don't cook during the day.
They cook at night or in the morning, right?
And so you've got to store energy
to make these things actually useful, right?
And I really like this program.
So I wanted to make that one of my Why This Matters.
And we'll go big on the next one.