Type of energy storage | Power density PDr (W/kg) | Energy density EDr (Wh/kg) | Power level MW | Time (hours) |
Ultra capacitor | 20000 | 30 | <1 | 10/3600 |
Lithium-ion battery | 300 - 800 | 150 - 250 | <1 | 4 |
lead acid battery | 200 - 400 | 25 - 30 | 0.001 - 10 | 4 |
Fly wheel | 150 - 3000 | 5 - 80 | 0.1 - 10 | 0.25 |
Flow battery | 5 - 40 | 90 - 400 | 0.01 - 100 | 4 |