Biofuels can provide energy without the reliance on environmentally harmful fossils fuels -- but scientists are still searching for a plentiful source. Craig A. Kohn demonstrates how cellulose, the naturally abundant tough walls of plant cells, might be the solution.
The Earth intercepts a lot of solar power: 173,000 terawatts. That’s 10,000 times more power than the planet’s population uses. So is it possible that one day the world could be completely reliant on solar energy? Richard Komp examines how solar panels convert solar energy to electrical energy.
