Answer No 1:
Organic matter that contains stored energy is called biomass.
Biomass can be described as an organic matter which can be used as fuel. Generally, biomass is used in generating electricity in large power stations.
Biomass has enormous amounts of energy stored in it. Biomass comes from plants or animals and has stored energy in it which can be used as fuel.
Answer No 2:
A resource that humans can use to produce energy is a natural resource like coal.
Humans can produce energy from various natural resources. These resources might be renewable or non-renewable.
Example of non- renewable energy source is coal. Coal is cheap and found abundantly. Coal is used as a fuel by humans.
Example of renewable energy source is wind. Wind energy is used to generate electricity by humans.
Answer No 3:
Hydroelectricity is an energy flow harnessed from flowing water.
The kinetic energy from flowing water is used for generation of electricity. Such kind of energy is called as the hydroelectricity. The water is run over huge turbines and the energy is converted into electrical energy.