The government and Korea Electric Power will apply the seasonal and time-based electricity bill reform plan step by step from April 16. The key point is to lower electricity bills in the daytime and raise them in the evening. They explained that this reform is a measure to expand renewable energy and respond to the energy crisis. In the daytime, when there is a lot of solar power generation, electricity is relatively more available, and in the evening after sunset, power demand gathers. The application starts with industrial use (B) first. The government says this sector accounts for about 53.2% of total electricity sales. The system is expected to expand gradually until June 1. Because of this measure, companies that use a lot of electricity need to adjust their usage time more carefully. The main point of the article is that electricity bills in Korea are now starting to change more depending on the time of day.
원문 보기Electricity is the same electricity, so why does the price change by time?
At first glance, it feels strange. Electricity comes through the same outlet, so why is it cheap in the daytime and expensive in the evening? But if you look inside the power grid, electricity is not a product that can be stored in a warehouse like goods. Production and consumption have to match almost at every moment.
What is important here is the duck curve (a phenomenon where solar power makes a lot of electricity in the daytime, so net load drops deeply, and then rises quickly again around sunset). As solar power increases, the share that other generators need to handle becomes smaller at midday. On the other hand, in the evening, solar output falls quickly, and people and factories use a lot of electricity at the same time, so the grid suddenly becomes tight.
So evening electricity is expensive not only because fuel costs go up. They need to urgently bring in power sources that can raise output quickly in a short time, like gas power generation or batteries. From the power grid operator's view, they also have to manage frequency (the balance condition of the electric system), reserve power (emergency backup power), and ramping (the ability to raise and lower power generation quickly), so the evening becomes a more expensive time.
In the daytime, thanks to solar power, electricity is relatively more plentiful,
and in the evening, solar power decreases while demand gathers, so electricity becomes more scarce.
There is extra power at midday, but it gets urgent around sunset — the feeling of the duck curve
This chart is not the real market price. It is a conceptual image showing how net load moves during one day.
Day and evening, the power grid looks very different like this
| Item | Daytime | Evening |
|---|---|---|
| Supply situation | A lot of solar power comes in, so electricity is relatively plentiful | Solar power drops fast, so the supply margin quickly gets smaller |
| Price signal | It can be low or very low | It tends to get high |
| Grid challenge | Problems like output limits and voltage control get bigger | Ramping, reserve power, and frequency control become important |
| Main response resources | Battery charging, moving processes earlier, load shifting | Gas power generation, battery discharge, demand reduction |
How did Korea's electricity rates get here
This reform did not suddenly fall from the sky. Korea's electricity pricing system had put other goals first for a long time, and now that direction is slowly changing.
Step 1: 1974, the progressive rate system became the standard
Residential electricity rates were built around a progressive rate system where the unit price rises a lot as you use more. Back then, the main point was controlling consumption and fairness, more than time-based price signals.
Step 2: In the 2000s, market discussion grew, but household rates stayed the same
There were talks about restructuring the power industry, but household electricity rates still had a strong policy-rate character. Because it directly affected prices and public opinion, the simple system stayed for a long time.
Step 3: 2009, industry already had time-of-use categories
Actually, time-based pricing is not completely new in Korea. Some general-use and industrial high-voltage customers already used divisions like off-peak, mid-load, and peak-load.
Step 4: 2016, debate over the progressive rate system shook the direction
As debate over electricity bills during heat waves grew bigger, more people said the old progressive rate system alone had limits. From this time, seasonal and time-of-use differential rates were mentioned more often as a mid- to long-term alternative.
Step 5: Since 2021, starting to add more cost signals
When the fuel cost adjustment charge and separate notice of climate and environmental costs were added, electricity rates began to reflect the real cost structure a little more.
Step 6: Since 2025, AMI lays the groundwork
AMI (advanced metering infrastructure, smart meter) must be installed so time-based usage can be measured accurately and different rates can be charged. As the technical base became ready, the system is only now starting to become real.
What is different between the old rate table and the new direction?
| Comparison item | Old focus | New direction |
|---|---|---|
| Basic idea | Manage total consumption with category-based rates and a tiered pricing system | Adjust usage time with time-based price signals |
| Key questions | How much did you use in one month? | When did you use the most? |
| Policy goals | Price stability, fairness, and encouraging saving | Peak reduction, renewable energy acceptance, and grid efficiency improvement |
| Needed technology | A relatively simple meter reading system | AMI, data analysis, and automatic control equipment |
| Changes in consumer behavior | Reduce total usage | Move usage time |
Why start with industrial first? Because that is where the most electricity is used
Why it is easier to adjust industrial use first, you can see it by comparing with household use
| Comparison item | Industrial | Household |
|---|---|---|
| Share of sales volume | The largest at about 53.2% in 2023 | About 15.1% |
| Difficulty of system adjustment | Contract categories are divided in detail, so adjustment is relatively easy | It is complicated because it is tied to the tiered system, welfare, and price issues |
| Political burden | Relatively low | High because it connects directly to public opinion and prices |
| Policy effect | Because they are large demand sites, the effect of price signals is big | Wide-ranging, but the speed of introduction may be slow |
| Main targets | Factories, production facilities, large workplaces | Households, apartments, small residential consumers |
Who benefits and who feels the burden
| Target | Direct impact | Good cases | Cases with heavy burden |
|---|---|---|---|
| Large factories | Very big | When they can shift processes to daytime or add ESS | When it is a continuous process that cannot stop production even in the evening |
| Shopping areas and large buildings | Medium | When they can control cooling and equipment operation earlier | When cooling and lighting are concentrated during commute-home hours |
| Self-employed people | The direct early impact is limited | When pre-cooling before business hours and replacing with high-efficiency equipment are possible | When refrigeration and air conditioning must be used continuously, like at convenience stores and cafes |
| Households | Small for now | When they use optional rate plans well in the long term | If it expands later, there may be more burden when evening use is concentrated |
Why can changing one rate table help the energy transition
But the rate plan alone is not enough
| Element | Why it is needed | Problems if it is missing |
|---|---|---|
| AMI smart meter | You need to measure usage by time accurately to apply this rate plan | If you do not know when it was used, the price signal gets weak |
| ESS battery | You can store cheap daytime electricity and use it in the evening | It becomes hard to connect daytime surplus with the evening peak |
| Grid investment | Transmission and distribution facilities need to hold up for renewable energy and load shifting to really work | Regional bottlenecks and output curtailment can grow |
| Fairness support | Protection is needed for consumers who cannot easily move their usage time | The burden on low-income groups and small businesses can grow |
So what does this change mean for our lives and the Korean economy?
This reform is not just about changing a few numbers in the rate table. It is closer to a signal that Korea's power system is moving from an era that only looked at 'how much electricity was used' to an era that also asks 'when it was used'. As renewable energy grows, this kind of change is actually becoming very hard to avoid.
For companies, electricity bills are now less likely to stay just a fixed production cost, and more likely to become part of management strategy. Companies that adjust process hours, add batteries, and use automatic control can have an advantage. On the other hand, industries that find it hard to reduce use during the evening peak can be in a worse position even if they use the same amount of electricity.
For people living everyday lives like us, the change right now may not feel very big. But in the long term, things like electric car charging time, air conditioner habits, and even the energy management way of apartment complexes may slowly change. So this news is an article about an 'industrial electricity rate reform,' but really, it is closer to a preview that Korean society as a whole has started moving toward using electricity more smartly.
Whether time-of-use rates will expand to homes too,
The next news point is how companies will connect ESS, automatic control, and electric vehicle charging.
We will tell you how to live in Korea
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