Thermal & Osmotic power

THERMAL & OSMOTIC POWER

Stakraft Osmotic Power Prototype, Norway

Thermal power: The sun's energy heats the surface water of the ocean. In tropical regions, the surface water can be much warmer than the deep water.
This temperature difference can be used to produce electricity with a heat pump device.

Osmotic power: Energy is produced from the difference in the salt concentration between seawater and river water through an osmosis process.

Thermal power: (still experimental)
The energy from the sun heats the surface water of the ocean. In tropical regions, the surface water can be much warmer than the deep water.

Ocean Thermal Energy Conversion

This temperature difference can be used to produce electricity with a heat pump device. The Ocean Thermal Energy Conversion (OTEC) system must have a large temperature difference of at least 25°C to operate, limiting its use to tropical regions.
See the movie:  "OTEC"

Osmotic Power: (still experimental)
Energy is produced from the difference in the salt concentration between seawater and river water through an osmosis process.
How it works:

Sea water and freshwater are put in two compartments divided by a semi permeable membrane, which has the capacity to let water pass but not salt. Due to the chemical properties of salt, freshwater will move through the membrane to the compartment where the salt-water is located. This diffusion is called osmosis and creates an upwards pressure in the salt-water compartment. This pressure can be used to turn turbines that power a generator.

Stakraft Osmotic Power Prototype

Osmotic energy plants can be built on locations where fresh and salt water are both available.
A difference in salinity of 3% corresponds to the potential energy of a 250-meter waterfall. 

See the movie:  "Osmotic Power"

 

Return to "Marine power"