変換方法 Kilowatt-時間
理解する Your Electricity Usage
Get the FormulasThe kilowatt-hour (kWh) is how electricity is measured and billed worldwide. Whether you're calculating appliance costs, comparing energy sources, or sizing a solar system, understanding how to convert kWh to other energy units is essential.
理解する Kilowatt-時間
A kilowatt-hour is not a rate—it's an amount of energy. It equals:
- 1,000 watts of power used for 1 hour
- 100 watts used for 10 hours
- 10 watts used for 100 hours
Formula: Energy (kWh) = Power (kW) × Time (hours)
A 100-watt (0.1 kW) light bulb running for 10 hours uses 1 kWh.
Conversion to Other Units
| Convert 変換元 | 変換先 | 乗数 |
|---|---|---|
| kWh | ジュール (J) | 3,600,000 |
| kWh | Megajoules (MJ) | 3.6 |
| kWh | BTU | 3,412 |
| kWh | Calories (cal) | 860,420 |
| kWh | Kilocalories (kcal) | 860 |
| kWh | Watt-hours (Wh) | 1,000 |
| kWh | Therms | 0.0341 |
Reverse Conversions
| Convert 変換元 | 変換先 kWh | Divide By |
|---|---|---|
| ジュール | kWh | 3,600,000 |
| MJ | kWh | 3.6 |
| BTU | kWh | 3,412 |
| Therm | kWh | 0.0341 (or × 29.3) |
ステップバイステップの例
Example 1: kWh to ジュール
Convert 5 kWh to joules:
- Use formula: ジュール = kWh × 3,600,000
- Calculate: 5 × 3,600,000 = 18,000,000 J (18 MJ)
Example 2: kWh to BTU
Convert 10 kWh to BTU:
- Use formula: BTU = kWh × 3,412
- Calculate: 10 × 3,412 = 34,120 BTU
Example 3: BTU to kWh
Convert 100,000 BTU to kWh:
- Use formula: kWh = BTU ÷ 3,412
- Calculate: 100,000 ÷ 3,412 = 29.3 kWh
Common Appliance Energy Usage
| Appliance | Power (ワット) | 時間/Day | kWh/Day | kWh/Month |
|---|---|---|---|---|
| LED bulb | 10 W | 5 | 0.05 | 1.5 |
| Refrigerator | 150 W avg | 24 | 3.6 | 108 |
| TV (55") | 100 W | 4 | 0.4 | 12 |
| Laptop | 50 W | 6 | 0.3 | 9 |
| Air conditioner | 1,500 W | 8 | 12 | 360 |
| Electric water heater | 4,000 W | 3 | 12 | 360 |
| EV charging | 7,000 W | 4 | 28 | 840 |
Energy Equivalents
変換先 put 1 kWh in perspective:
| 1 kWh Can... | Equivalent |
|---|---|
| Run a 100W bulb | 10 hours |
| Run a laptop | 20 hours |
| Watch TV (55") | 10 hours |
| Run a microwave (1000W) | 1 hour |
| Drive an electric car | 3-4 miles |
| Heat water | ~1 gallon from cold to hot |
kWh in Context: Fuel Comparisons
| Energy Source | Energy Content | Equivalent kWh |
|---|---|---|
| 1 gallon gasoline | ~121 MJ | ~33.7 kWh |
| 1 gallon diesel | ~137 MJ | ~38 kWh |
| 1 therm natural gas | ~105.5 MJ | ~29.3 kWh |
| 1 kg coal | ~24 MJ | ~6.7 kWh |
| 1 kg wood | ~16 MJ | ~4.4 kWh |
まとめ
The kilowatt-hour is the standard unit for measuring electrical energy consumption. Converting to joules (multiply by 3,600,000) or BTU (multiply by 3,412) allows comparison with other energy sources and calculations. 理解する kWh helps you estimate costs, size renewable energy systems, and make informed energy decisions.