Osmosis is the movement of?

Osmosis is the movement of water molecules from a higher water potential   to a  lower water potential across a partially permeable membrane.

Please note two things:

Now, If you want the definition in terms of solute concentration, it should be:

Osmosis is the movement of water molecules from a Low concentration   to a  high concentration across a partially permeable membrane.

Also, Note that  no energy is required for this process.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint