MW and MWh
megawatt · megawatt-hour · GW · GWh · 메가와트
MW (megawatt) and MWh (megawatt-hour) are kW and kWh scaled up to the mega unit. They are used for large values such as plant size or power market volumes.
MW measures power (the size at an instant) and MWh measures energy (the amount over time). Even larger values are written in GW and GWh.
The Electricity Market Operation Rules state a generator's maximum generating capacity in MW and the available capacity generators bid in MWh. According to KPX statistics, Korea's installed capacity in 2025 was 146,157 MW and the power market's traded volume was 547,163 GWh. The first is the size of the fleet; the second is the amount actually traded over the year.
News-reading tip: check first whether the unit after a number is MW or MWh. Traded volume and generation are also different values: market trades are metered at the sending end, after subtracting power used inside the plant and similar losses.
Sources
- 전력시장운영규칙(2026-07-25 시행) 제1.1.2조 제1·2·14·21호(중앙급전발전기, 공급가능용량 MWh, 송전단 전력, 최대발전용량 MW)
- 전력거래소, 「2025 전력시장통계」 표 1-1 전력시장참여 설비용량 · 표 1-2 전력거래량