The transport of molecules of a particular solute from inside an animal cell across the membrane to extracellular fluid always requires energy when the following conditions are met:

* The solute is moving against its concentration gradient: This means the solute is moving from an area of lower concentration (inside the cell) to an area of higher concentration (extracellular fluid). This process is called active transport and requires energy to move molecules against their natural tendency to diffuse down the concentration gradient.

Examples:

* The sodium-potassium pump moves sodium ions out of the cell and potassium ions into the cell, both against their concentration gradients.

* The transport of glucose into some cells occurs against its concentration gradient, requiring energy.

Important Note:

* Passive transport does not require energy. This occurs when the solute moves down its concentration gradient, from a high concentration to a low concentration. Examples of passive transport include diffusion, osmosis, and facilitated diffusion.

So, in summary, the movement of a solute from inside a cell to the extracellular fluid always requires energy when it is moving against its concentration gradient.