Exergy is the useful energy, then about this adea can solve the problem using exergy method.

Thanks Saad,

Can you please explain more about the best exergy method

well, exergy is the maximum work you can get from a system at any condition following reversible process to reach the thermal, mechanical and chemical equilibrium with the surrounding. no matter what kind of system. Then the normal trend of every system is to evolute until that equilibrium is reached. Systems following non reversible paths are distroying exergy or generating entropy. When systems path reversible or "perfect" path they has a minimum efect on the surrounding then the exergy is usefull to evaluate as close to the perfection our system are.

Good explain.. Dr. Ruben B.

Dear, Khalid E.

The exergy of a system is the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir. When the surroundings are the reservoir, exergy is the potential of a system to cause a change as it achieves equilibrium with its environment. Exergy is the energy that is available to be used. After the system and surroundings reach equilibrium, the exergy is zero.

Dear, Khalid E.

the useful energy of the earth system is life. as Gaia concept, we have a work potential as carnot motor cycle in the earth. in ecosystem level, you need to know some interactions in different parts of ecosystem( source of energy in ecosystem: solar energy(it depends on albedo number)) and exergy storage in ecosystem. Moreover, considering ecosystem as an open and close system can help you to find the main streams.

Dr. Masoomeh B.,

Good and interested answer.

Hello Khalid Elkalay

I have two work using thermodynamics concept in ecosystem:

Article Entropy generation as an environmental impact indicator and ...

Article A general exergy-based environmental impact index