Comparison between Exergy(Availability) and Energy can be made in the following ways.
| S.no |
Exergy (Availability)
|
Energy
|
|---|---|---|
| 1 | Exergy(Availability) doesn’t follow the law of conservation of energy. | Energy follows the law of conservation of energy. |
| 2 | It is a function of states of the matter under consideration and the ‘environment’. | It is a function of the state of matter under consideration. |
| 3 | It is estimated with respect to the state of reference imposed by the environment. | It may be calculated based upon the assumed state of reference. |
| 4 | Exergy always depends upon pressure. | In case of ideal gas, energy does not depend upon pressure. |
| 5 | Exergy increases with a temperature drop at low temperatures. For constant pressure processes, exergy attains minimum value at the temperature of the environment. | Energy increases with rising of temperature. |
| 6 | Exergy has positive value for ideal vacuum. | Energy is zero for an ideal vacuum. |
