Fuels & Batteries

Energy per kilogram

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Petrol stores about 50× more energy per kg than a lithium-ion battery.
• Electric motors are about 3× more efficient than engines, narrowing the gap.
• Nuclear fuel stores millions of times more energy per kg than chemical fuel.

Steps

1. Energy density
2. Petrol vs battery
3. The efficiency gap
4. Hydrogen versus petrol
5. A battery to match a tank
6. A gram of uranium