This is produced by either gradient of electrical or chemical potential.

So, water potential of any system is equivalent to the chemical potential of water in that system.

It follows that the sum of chemical potentials is also zero.

by water bound with progressively lower chemical potentials.

The bigger the difference in chemical potential, the

Below that temperature the chemical potential is zero.

These ideas lead to one of the most important variables in thermodynamics: chemical potential. x

In parallel, the chemical pathway uses a redox material which undergoes direct photoreduction in the receiver to store the solar energy as chemical potential.

That leads us to the expression of the chemical potential for a gas

The complete expression for the chemical potential of species i is:

represents the reference value of the chemical potential at STP.

is chemical potential of substance α {\displaystyle \alpha }

Thermo-chemical storage uses thermal energy “to drive a reversible endothermic chemical reaction, storing the energy as chemical potential.

For an ideal gas, the chemical potential is given by

and chemical potential μ i {\displaystyle \mu _{i}}