New ways of making energy are being researched all the time.
Biomass energy uses natural materials like trees and plants to make electricity but it can also mean using waste products such as paper and cardboard that can't be recycled in other ways and also rubbish.
When rubbish decomposes, it gives off a gas called methane. A machine called a microturbine captures the methane gas and uses it to run a small jet engine to produce electricity.
Similarly, animal waste such as cow manure, gives off methane gas too. Some farms in the UK have an anaerobic digester on site to turn the methane into electricity.