Solar and wind energy is the most safe. Of the renewable energies, nuclear can produce nuclear waste and go critical, while hydroelectric power can displace many acres of land. Wind and solar energy produce no waste, do not pollutes, and do not displace.
There are a wide variety of logos that are used to indicate an environmentally friendly product. Most of these logos are green, and many contain some sort of tree.
Usually this is some sort of potential energy, especially chemical energy, but also nuclear energy.
It is radiated electromagnetic energy, the only sort that can travel through space.
kinetic energy
Solar energy
Spring potential energy.
chemical potential energy
Kinetic Energy.
Potential energy.
Any,the stronger the better
If you're talking about valence shells, it would be the first. The closest one to the nucleus of an atom has the most amount of POTENTIAL energy. It requires some sort of chemical or magnetic action to get the energy.
Sunlight gets trapped in the chlorophyll, which convert it into chemical energy. (ATP) The cell cannot use raw sunlight, but it has to use some sort of energy to perform most tasks.