Energy in all foods comes from calories, which are in starches, fats and proteins. Peanuts contain a high percentage of fat, which is the source of most of their calories, or energy.
Each gram of fat has 9 Calories. Compare this with 4 Calories per gram of carbohydrate or protein. So it is clear that fats of all types including saturated, PUFA, MUFA, cholesterol, trans-fat are...
It depends on the size and weight of the peanut to give a specific amount. However, peanuts are approximately 50% oil (between 45% and 55% depending on the specific peanut).