Norway now holds the world’s first power plant to create technology that uses osmosis to generate electricity. Sited in a bay in south-east Norway, the plant opened on the 25th of November.
Statkraft is the company behind this, and is the third largest energy producer in the Nordic Region. FYI, they are a state owned electricity company. Their first plant prototype has been unveiled, and it can is still undergoing testing.
What is all the fuss about? Well, no one has actually used osmosis to produce electricity before, so this technology is new. There are of course many obstacles, but with the first prototype now made, they can test the system and see if it works before scaling it up! That makes sense, but wait, what’s osmosis again?
Osmosis is a process of movement of water. It defines the spontaneous, or passive, water movement from a solution with a lower concentration of solutes (substances dissolved in water) to a solution with higher concentration of solutes, through a semi-permeable membrane. See the figure below for an example. The beaker holds two solutions, and the dashed line is the membrane. The solution on the left is more concentrated, and so water moves from the right into the left. See here for an animation on osmosis.
Using this concept, Statkraft intends to use salt and fresh water from the bay as the two solutions, creating a pressure gradient that pushes up the water level differences and eventually drives a turbine to generate electricity.
Still under testing, the prototype is able to produce enough energy to boil 2-3 kettle pots, and the company is still resolving problems of river bacteria and silt gathering on the membranes – their first obstacle before they scale up to produce energy for countries around the region.
It reminds me of when they first came up with the technology for reverse osmosis, the process that Singapore now uses to produce Newater as well as for desalination of salt water, that was an exciting time!