>> this conversation is over. >> what happens to solar energy when there's no sun outside? >> it stores the energy from when there is sunlight. >> when energy is coming along faster than solar power. >> what happens when the wind stops blowing? >> it restores it, like, it just builds up the energy. >> come again? >> so, did you drive or did you walk? >> um, i actually drove. >> i drove. >> uh-oh. what about all those missions? i'm sorry? >> i don't know what we're talking about. >> this isn't about us taking a trip across the country. this is about young people standing up for our future. >> how did you get here? >> i drove. >> you don't have shoes on. what is that about? >> i didn't want to wear them. >> that's the truth. >> what i'm going to do when i get home is plant some trees. >> you are going to plant trees when you get home? >> i love anybody who loves trees. >> it happens to be a great passion of mine.