Thermal energy Thermal energy is the energy an object has because of the movement of its molecules, and heat can be transferred from one object to another object. Thermal energy is also the energy that is generated and measured by heat.
Gravitational energy Gravitational energy is energy associated with gravity or gravitational force. The gravitational potential energy of an object depends on the height above the ground.
Solar energy Solar energy is the solar radiation that reaches the earth. Solar energy can be converted directly or indirectly into other forms of energy, such as heat and electricity.
Thermal I think we should develop this to the fullest, because if we didn't have any we wouldn't have a sun. Then it would be dark all the time and we wouldn't have any heat.