**Common Units of Energy – **Energy is the capacity to do work and exists in various forms, including kinetic, potential, electrical chemical, and thermal. It’s classified into renewable (like solar and wind) and non-renewable (such as fossil fuels and nuclear). Common units for measuring energy include the joule, calorie, kilowatt-hour, and British Thermal Unit. Understanding energy units and sources is crucial for addressing our energy needs sustainably.

**What is the SI Unit of Energy?**

The international unit of energy, the joule, is named in honor of James Prescott Joule, a British physicist whose groundbreaking work played a pivotal role in developing the concept of energy. In fundamental terms, 1 joule is equal to 1 newton-meter (1 N·m). In the context of SI base units, it can be represented as 1 joule = 1 kilogram·meter²/second², illustrating its relationship to mass, distance, and time.

**What is the CGS Unit of Energy?**

One erg is equal to 10^{-7} J. An erg is defined as the amount of work done by the force of one dyne at a one-centimetre distance.

**What is the Unit Of Energy In MKS System?**

In the MKS (meter-kilogram-second) system, which is a metric system of units commonly used in science and engineering, the unit of energy is the joule (J). So, the MKS unit of energy is the joule.

**Units of Energy List**

Energy units can be preceded by various factors, and there are usually different units for measuring energy. Some common units include:

- British thermal unit (BTU)
- Kilowatt-hour (kWh)
- Calorie
- Electronvolts (eV)
- Hartree (the atomic unit of energy)
- Rydberg units
- Barrel of oil

**Energy Conversion**

Following is the table with the energy conversion list:

Unit | Joule | Calorie | BTU | Kilowatt-hour |

Joule | 00 | 0.2390 | 0.000948 | 2.77778E-07 |

Calorie | 4.187 | 00 | 0.00397 | 1.16279E-06 |

BTU | 1055 | 252 | 00 | 0.000293 |

Kilowatt-hour | 3.6E6 | 8.6E5 | 3412 | 00 |

**Commercial Unit of Energy**

Kilowatt-hour is the commercial unit of energy.

When large quantities of energy are expressed, the SI unit of energy becomes small. Therefore, the commercial unit is used.