Supply

Reading power · Supply

\"100 MW solar farm completed.\" \"Work begins on 100 MW gas power plant.\" The two headlines share a number, but the electricity the two plants make in a year is very different. MW is the power a plant can put out at a single moment; MWh is the amount it actually makes. In car terms, it is the difference between engine power and distance driven.

Reading power · Supply

In 2025, one in every three units of electricity bought and sold in Korea's power market came from nuclear plants — even though nuclear capacity is only a little over half of LNG capacity. And in 7,295 of that year's 8,760 hours, it was an LNG generator that set the wholesale price.

Reading power · Supply

At 3:11 p.m. on September 15, 2011, lights went out one after another all over Korea. It was not a war or a typhoon; there was simply a little too little electricity. That is why a market for a product that is hard to stockpile is shaped differently from an ordinary market.

Reading power · Supply

SMP, the wholesale price of electricity set for each hour, is the highest price among the generators in that hour's schedule that are eligible to set the price. The SMP, an annual average of 196.65 won in 2022, came down by more than 40% to 112.72 won in 2025. Even so, the bill you pay at home is charged not at SMP but by a fixed rate table.

Reading power · Supply

Two power plants sell electricity in the same hour at the same SMP, and are paid different sums. A plant's pay has three lines — the value of the power it made, the value of the capacity it keeps ready, and an adjustment attached to only some plants. The third line never shows on your bill, but it changes the price KEPCO pays for power.