Why Does My Electricity Bill Suddenly Increase Even If I Don't Use More Air Conditioning? Taiwan Power Company Reveals the Key to High Bills

During the hot summer days, many citizens are puzzled when they receive their electricity bills. Even though they haven't used more air conditioning than usual, their electricity bills have suddenly increased by several hundred dollars, or even more than the previous period. In fact, a higher bill doesn't necessarily mean that air conditioning usage has significantly increased. It could also be related to summer electricity prices, progressive pricing tiers, and the bimonthly billing system. Especially when a household's electricity usage just crosses the tier threshold, the excess of each degree of electricity will be charged at a higher unit price, making the increase in electricity bills more noticeable.

Why does the electricity bill suddenly become more expensive even if the air conditioning is not used more? Taiwan Power Company points out that the implementation period for residential summer electricity prices is from June 1st to September 30th each year. Among them, the rate for monthly electricity usage of 120 degrees or less is 1.78 yuan per degree for both summer and non-summer months. However, from the 121st degree onwards, the summer electricity price is higher than the non-summer price, and the more electricity is used, the higher the unit price of the subsequent tiers becomes.

Therefore, even if citizens feel that the air conditioning usage time is similar to the previous period, as long as the total electricity usage of the refrigerator, dehumidifier, water heater, washing machine, dryer, and other household appliances increases, or the electricity usage just crosses the tier, the bill amount may still significantly increase.

Taiwan Power Company statistics show that in 2025, the average monthly electricity usage for residential users in non-summer months is approximately 308 degrees. During the summer months from June to September, the average electricity usage increases to 418 degrees, with an increase of nearly 40%. Taiwan Power Company states that the main reason for the increase in summer bills is usually still the air conditioning driving up the overall electricity usage, plus the electricity usage exceeding 120 degrees is subject to the summer rate. The two factors combined make it easy for electricity bills to show a significant difference.

What is the residential summer electricity price in 2026? Let's take a look at the six tiers at once

Currently, general residential electricity usage adopts a six-tier progressive pricing method. The summer and non-summer rates applicable in 2026 are as follows:

Monthly electricity usage tier Summer electricity price Non-summer electricity price 120 degrees or less 1.78 yuan per degree 1.78 yuan per degree 121 to 330 degrees 2.55 yuan per degree 2.26 yuan per degree 331 to 500 degrees 3.80 yuan per degree 3.13 yuan per degree 501 to 700 degrees 5.14 yuan per degree 4.24 yuan per degree 701 to 1000 degrees 6.44 yuan per degree 5.27 yuan per degree 1001 degrees or more 8.86 yuan per degree 7.03 yuan per degree

From the rates, it can be seen that the first 120 degrees of electricity usage are not affected by the summer electricity price. The real difference starts from the 121st degree. Especially when the household electricity usage exceeds 500 degrees, 700 degrees, or 1000 degrees, the excess part will enter a higher unit price tier, and the bill increase will be more noticeable.

Does exceeding 1 degree enter a higher tier? Not all electricity becomes more expensive

Many people see "1001 degrees or more, 8.86 yuan per degree" and mistakenly think that as long as the electricity usage reaches 1001 degrees, all previous electricity usage will be calculated at 8.86 yuan per degree.

Taiwan Power Company clarifies that residential electricity prices adopt a segmented progressive billing method. Each tier is calculated separately, and only the part exceeding the threshold will be subject to the next tier's rate. Taking 1001 degrees as an example, only the 1st degree of electricity exceeding 1000 degrees is subject to 8.86 yuan per degree, and the previous 1000 degrees are still calculated according to their respective tiers, and the entire bill is not calculated at the highest unit price.

Similarly, if the summer single-month electricity usage increases from 500 degrees to 501 degrees, the first 500 degrees are still calculated according to the previous three tiers, and only the 501st degree of electricity enters the tier of 5.14 yuan per degree. In other words, the statement "exceeding 1 degree enters a higher tier" is to some extent correct, but only that 1 degree becomes more expensive, not all electricity is recalculated.

However, when a household continues to increase electricity usage, the number of degrees falling into higher tiers increases, and the cumulative effect will still significantly push up the entire bill. The real key to increasing electricity bills is not just crossing the tier threshold, but how much electricity falls into the higher rate range.

Electricity bills are billed every two months, and the tier thresholds are also doubled

General residential electricity bills are usually billed every other month, meaning that the bill amount is usually the total for two months. Therefore, the electricity usage and amount on the bill are typically the sum for two months.

Taiwan Power Company explains that the progressive tiers for users with bimonthly billing will also be proportionally doubled. For example, if the first 120 degrees per month are subject to 1.78 yuan per degree, if the billing period is two months, it will be changed to the first 240 degrees subject to 1.78 yuan per degree. The tier of 121 to 330 degrees per month is equivalent to the 241st to 660th degrees for two months.

Therefore, when citizens see that a single bill uses 800 degrees of electricity, it does not mean that 800 degrees are used in a single month. First, divide by 2, convert it to an average of approximately 400 degrees per month, and then determine which electricity price tier it actually falls into.

Electricity bills suddenly increase, first check three places on the bill

Taiwan Power Company reminds that if you find that the bill amount is much higher than the previous period, do not just compare the payment amount. First, check whether the "current period electricity usage" has increased. Since the electricity usage habits in winter, spring, and summer are very different, directly comparing the summer bill with the previous period is easy to be affected by seasonal factors. A more reasonable way is to compare it with the same month last year or the same billing period.

Next, citizens should confirm the meter reading date and billing days covered in the bill, and pay attention to whether it includes the allocation of electricity fees for the building's elevator, parking lot lighting, water pumping equipment, or other public facilities. The electricity fee inquiry service provided by Taiwan Power Company can also check information such as the billing period, average electricity price, and whether there is an allocation of public facility electricity fees.

Finally, it is recommended to compare the total electricity usage of this period with the same period last year. If the electricity usage has significantly increased, it usually means that the overall electricity usage at home has changed. If the usage is similar but the amount has increased, you can further check the summer rate, tier crossing situation, and public electricity fee allocation.

How to open the air conditioning to save the most electricity? Taiwan Power Company teaches three ways to avoid crossing tiers

To avoid summer electricity usage from jumping into a higher tier all at once, Taiwan Power Company suggests setting the air conditioning to 26-28 degrees Celsius and using it with a fan or circulating fan to accelerate the flow of cold air indoors. For every 1 degree increase in the air conditioning setting temperature, approximately 6% of air conditioning electricity can be saved.

The air conditioning filter should also be cleaned every 2-3 weeks to prevent dust and lint from blocking the air intake and reducing cooling efficiency. Taiwan Power Company points out that regularly cleaning the air conditioning filter can save up to approximately 10% of air conditioning electricity per year.

In addition, citizens can develop the habit of regularly checking the electricity meter or using the Taiwan Power APP to track electricity usage. If it is found that the electricity usage is approaching the tier thresholds of 500 degrees, 700 degrees, or 1000 degrees, the setting of the air conditioning and the usage methods of other high-energy-consuming household appliances can be adjusted in advance to avoid more electricity falling into the higher rate range.

In summary, even if the air conditioning is not obviously used more, it does not mean that the overall electricity usage is completely the same. Summer electricity prices, other household appliances, progressive tiers, and public electricity fee allocation can all lead to an increase in the bill. When receiving a high electricity bill, do not immediately think that all electricity is charged at 8.86 yuan per degree. Check the actual electricity usage and the calculation method of each tier to find out the real reason why the bill suddenly becomes more expensive.