Absorption Power
The hero can absorb a specific type of energy and actually gain Health points by converting the energy into Self-Healing. The hero gains a number of Health points equal his Power rank number each time he is hit by his specific form of absorbable energy. This addition to Health quickly heals any damage the hero had suffer, and acts as a buffer to absorb consequent damage.
In the absence of life-sustaining materials, this Power can act as a substitute for air, water, and food. The hero converts energy into healing power for the damage he's taking from suffocation, dehydration, starvation, and any other unpleasant results of not living careful. Unfortunately, this requires a steady supply of energy to convert. Consider Galactus. He is perpetually starving. He uses this Power to absorb the energy of life-forces and convert it into his own life force. Yet, draining 10 billion life-forces only sustains him for a single year, at most. Your hero won't last anywhere near as long.
There is the danger that your hero will actively seek out energies he can absorb and heal himself with. The danger occurs if the energy type is a dangerous one that does great damage wherever it occurs. For example, consider a character whose Absorption Power affects hard radiation. In the absence of other superbeings who possess Radiation Powers, the character might resort to breaking into reactors or even purposefully detonating nuclear bombs to get the energy he needs. (And you thought muties had a public image problem.)
If the hero possesses an Energy Emission Power, he cannot use it directly to affect himself.
Range: Column B