Japanese Electricity Bill Breakdown: Base Charge, Fuel Cost Adjustment and Renewable Energy Levy

An electricity bill adds up four things

The bill on a typical household plan (Juryo Dento, a metered plan) is the sum of these four.

• Base charge: a fixed charge set by your contract amperage. You pay it even if you use no electricity at all.
• Energy charge: the kWh you use multiplied by a unit rate. It has three tiers, with the rate rising the more you use.
• Fuel cost adjustment: an adjustment reflecting price changes in the fuel used to generate power. The rate changes monthly and can be negative.
• Renewable energy levy: a charge shared by everyone in proportion to usage, covering the cost of buying renewable power. The rate is the same nationwide.

Here's a 300 kWh month built up on the rates of TEPCO Energy Partner's Juryo Dento B with a 30 A contract (with a fuel cost adjustment of ¥0/kWh).

Rates differ by power company, plan and fiscal year. When checking your own bill, substitute the rates on your meter slip.

The base charge depends on contract amperage

The Juryo Dento B base charge depends on the maximum current you can draw at once (contract amperage). It's a charge for the size of that limit, above which the breaker trips.

Each 10 A step is ¥311.75 a month, or ¥3,741 a year. If you have a 40 A contract and the breaker has never tripped, there's room to go down to 30 A. But using the air conditioner, microwave and hair dryer at once can exceed 3,000 W, so going too low can get in the way of daily life.

The energy charge rate rises with use

On Juryo Dento plans, monthly usage is split into three tiers, each with a different rate. The idea is to keep the minimum needed for daily life cheap and charge more for heavy use.

A 400 kWh month puts 100 kWh in tier 3, adding ¥4,049, for a total of ¥16,704. Using just 100 kWh more than a 300 kWh month raises the bill by ¥4,447. That's why the cost per kWh is higher in high-usage summer and winter months, and why saving electricity also pays off most in those months.

Fuel cost adjustment and renewable energy levy

Both are calculated as "usage × rate", but their rates are set in completely different ways.

• Fuel cost adjustment: the rate changes monthly based on import prices for crude oil, LNG and coal. It's positive when fuel is expensive and negative when it's cheap. For a household using 300 kWh, a ¥1 change in the rate changes the bill by ¥300. In months with government subsidies, the rate shown is lower by that amount.
• Renewable energy levy: everyone who uses electricity shares the cost of power companies buying solar and wind power. The government sets the rate each fiscal year, the same nationwide, and it's revised from the May meter reading each year. The fiscal 2025 rate is ¥3.98/kWh, or ¥1,194 a month and ¥14,328 a year at 300 kWh.

The fuel cost adjustment is the main reason a bill moves up and down from month to month even with the same usage. If you feel "I used about the same as last month, but it's higher", check the fuel cost adjustment rate before your usage.

Find your home's rate per kWh from your bill

Whatever your plan or power company, "bill ÷ usage" gives your home's real rate per kWh. For example, a ¥9,800 bill on 240 kWh comes to ¥40.83. Using this rate to calculate appliance costs gives figures close to your bill.

In low-usage months, the fixed base charge is divided by fewer kWh, so the rate rises. In high-usage months, the more expensive tier 3 rate kicks in. So the real rate is lowest around 300 kWh and higher on both sides. Comparing for someone living alone (185 kWh), a 20 A contract gives ¥39.47 and a 40 A contract ¥42.84, so the difference in base charge shows directly in the rate.

Check your meter slip with the tool

1. 1

   Enter usage and contract amperage

   On the "Look up from your bill" tab of the Electricity Cost Calculator, enter the usage (kWh) from your meter slip and choose a contract amperage from 10 A to 60 A.

2. 2

   Match the rates to your meter slip

   Open "Adjust the rates" to overwrite the base charge, the three tier rates, the fuel cost adjustment rate and the renewable energy levy. The fuel cost adjustment rate can also be negative.

3. 3

   Check the breakdown

   From the base charge to the renewable energy levy, each item is listed in the form "kWh × rate". Comparing it line by line with your meter slip shows where the amount is growing.

4. 4

   Use the real rate on all tabs

   Enter your bill to get the real rate. Press "Use this rate on all tabs" to recalculate appliance costs at your own home's rate too.

You can see whether your usage is high or low by household size in average electricity bills. How to calculate the cost of a single appliance is covered in how to calculate electricity costs.

FAQ

What is the fuel cost adjustment?

It's an adjustment that reflects price changes in the crude oil, LNG and coal used to generate power in your electricity bill. It's calculated by multiplying usage by the fuel cost adjustment rate, which changes monthly. When fuel is cheap, it goes negative and is subtracted from your bill. For a household using 300 kWh, a ¥1 change in the rate changes the bill by ¥300.

How much is the renewable energy levy?

It's your usage multiplied by a rate set by the government. The rate is the same nationwide and is revised from the May meter reading each year. In fiscal 2025 it's ¥3.98/kWh, or ¥1,194 a month and ¥14,328 a year for a household using 300 kWh. This rate doesn't change even if you switch power company or plan.

Is there a way to lower the base charge?

In regions that use amperage, lowering your contract amperage lowers the base charge. On TEPCO EP's Juryo Dento B, each 10 A is ¥311.75 a month, or ¥3,741 a year. But the limit on simultaneous power use also falls, so households that run the air conditioner and microwave together should stay within what won't trip the breaker.

How do I find the rate per kWh for my electricity?

Dividing the bill on your meter slip by usage gives a real rate that includes the base charge and levy. A ¥9,800 bill on 240 kWh comes to ¥40.83. The tier rates on the slip cover only the energy charge, so the real rate is more accurate when you want figures matching your bill.

Why did my bill go up with the same usage?

Changes in the fuel cost adjustment rate are the main cause. In months when government subsidies end or fuel prices rise, the bill rises even with the same usage. The renewable energy levy rate is also revised from the May meter reading each year. Comparing the rate section of your meter slip with the previous month shows what changed.