Convert Gigajoules to Megawatt-Hours
Convert Gigajoules (GJ) to Megawatt-Hours (MWh) instantly and accurately.
Conversion Formula
MWh = GJ × 0.2777777778
About Gigajoules
A gigajoule (GJ) is 10⁹ J - the scale of fossil-fuel commodity volumes. One barrel of crude oil contains ~5.80 GJ; one metric tonne of hard coal ~29.3 GJ. Canadian energy bills express household consumption in GJ: average Canadian households use ~100-130 GJ/year. A 1 GW power plant at 33% efficiency burns ~10.9 GJ/h of fuel to generate 1 GWh = 3.6 GJ of electricity. Detonation of 1 tonne of TNT releases 4.184 GJ. 1 GJ = 10⁹ J = 277.78 kWh = 947,817 BTU = 9.4782 therms.
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
| Gigajoules (GJ) | Megawatt-Hours (MWh) |
|---|---|
| 1 GJ | 0.277778 MWh |
| 2 GJ | 0.555556 MWh |
| 5 GJ | 1.38889 MWh |
| 10 GJ | 2.77778 MWh |
| 25 GJ | 6.94444 MWh |
| 50 GJ | 13.8889 MWh |
| 100 GJ | 27.7778 MWh |