WHAT IS ENERGY?

It is the capacity of a physical system to perform work.

Energy exists in some forms such as heat, kinetic or mechanical energy, light, potential energy, electrical, or other forms.

According to the law of conservation of energy, the total energy of a system stays constant, although energy may transform into another form. 

The SI unit of energy is the joule (J) or newton-meter (N * m). The joule is also the SI unit of work.

The energy we consume has many different uses:

• Household uses: operating household appliances, heating systems, means of transport, agriculture, etc.
• Industrial uses: the operation of factories and bussinesses, construction, agriculture, etc.