Question

why should we save energy

Answer 1

we should save energy to save the Earth and for the future generations.

Answer 2

While Looking to the future, supplies of fossil fuels are dwindling, which means that electricity and gas could become much more expensive over the next decade.

Conserving energy I mean saving Energy now will help reduce the impact of this and help us get used to using less so we can cope when prices are more expensive....!