Magnets do not require an external energy source to repel or attract other magnets. The repulsive or attractive forces between magnets are inherent properties of magnetic materials and are a result of the alignment and movement of the electrons within those materials.
In simple terms, magnets contain microscopic regions called magnetic domains, where the magnetic fields of individual atoms align in a specific direction. When two magnets approach each other, these magnetic domains interact, causing either attraction or repulsion depending on their alignment.
The energy associated with magnetic forces is derived from the internal energy of the magnetic material itself. This energy is stored in the alignment of the magnetic domains and does not require an external supply to be maintained.
However, it's important to note that magnets can lose their magnetism over time due to various factors. These factors include exposure to high temperatures, strong external magnetic fields, or physical damage that disrupts the alignment of the magnetic domains. When a magnet loses its magnetism, it means that its magnetic domains have become disordered or realigned in a random fashion, reducing or eliminating its ability to attract or repel other magnets.
In summary, the energy responsible for the repulsion or attraction between magnets is inherent to the magnetic material itself, but magnets can lose their magnetism over time under certain conditions.