Convert Joules to Megawatt-Hours
Convert Joules (J) to Megawatt-Hours (MWh) instantly and accurately.
Conversion Formula
MWh = J × 2.777777778e-10
About Joules
The joule (J) is the SI unit of energy, defined as one newton acting through one metre (1 J = 1 N·m = 1 kg·m²/s²). Named after James Prescott Joule, whose 1840s paddle-wheel experiments established the mechanical equivalent of heat (~4.15 J = 1 calorie). One joule is modest: it lifts a 100 g apple by 1 m, heats 0.239 mL of water by 1°C, or powers a 1 W LED for 1 second. Daily adult resting metabolism is ~6-9 MJ. 1 J = 1 W·s = 0.23901 cal = 9.4782 × 10⁻⁴ BTU = 2.7778 × 10⁻⁷ kWh.
About Megawatt-Hours
A megawatt-hour (MWh) is the energy from 1 MW for one hour - exactly 3.6 GJ. It is the standard unit for wholesale electricity trading. Power purchase agreements (PPAs) specify capacity and price in $/MWh or €/MWh. A 5 MW wind turbine at full capacity generates 5 MWh/h. Primary aluminium smelting consumes 13-15 MWh per tonne. The Moss Landing battery (California) stores 3,287 MWh. The daily output of a 1 GW nuclear plant at 90% capacity factor is ~21,600 MWh. 1 MWh = 3.6 GJ = 3,412,141 BTU = 1,000 kWh.
Quick Reference Table
| Joules (J) | Megawatt-Hours (MWh) |
|---|---|
| 1 J | 2.778 × 10-10 MWh |
| 2 J | 5.556 × 10-10 MWh |
| 5 J | 1.389 × 10-9 MWh |
| 10 J | 2.778 × 10-9 MWh |
| 25 J | 6.944 × 10-9 MWh |
| 50 J | 1.389 × 10-8 MWh |
| 100 J | 2.778 × 10-8 MWh |