Animals usually store excess energy in fat cells as fats.
Glycogen is the primary form of short-term energy storage in animals. It is stored in the liver and muscles and can be quickly broken down into glucose for energy during times of increased energy demand.
Animals have molecules that can store energy for short term and long term periods of time. Animals use carbohydrates as short term storage and Lipids as long term storage.
glycogen
Both plants and animals store chemical energy in a nucleotide called ATP (Adenosine-TriPhosphate). This nucleotide acts as a coenzyme for different processes in cells when it releases energy by turning into ADP (adenosine Diphosphate).
Humans store energy for short term use as glucose in the form of glycogen, primarily in the liver and muscles. Glycogen is broken down into glucose when the body needs a quick source of energy.
Glycogen is the polysaccharide that serves as the form of short-term energy storage for animals. It is stored mainly in the liver and muscles, where it can be quickly broken down into glucose for energy when needed.
Fat is the long term energy storage medium for most animals. Glycogen is the short term storage medium. Glycerol is the backbone of triglycerides.
Humans store energy for short-term use as glycogen in the liver and muscles. Glycogen is a form of carbohydrate that can be quickly converted to glucose for energy when needed.
When plants store sugar they store it as food
Carbohydrates function in short-term energy storage (such as sugar) and as intermediate-term energy storage (starch for plants and glycogen for animals). Fats and oils function in long-term energy storage. Fats yield 9.3 Kcal/gm, while carbohydrates yield 3.79 Kcal/gm. Fats thus store six times as much energy as glycogen.
Indeed, both inductors and capacitors store energy only short-term - very short-term. A battery is designed to store energy for much longer - for hours, days, or even months at a time.
Body Fat is used for long term storage. For short term storage the body uses Adenosine Triphosphate (ADT.)