Sustainable development blog : ecology and humanitarian aid

The Human being has already domesticated the solar heat, the sunlight, the wind force, the water flows and the high /low sea tide to generate electricity. Obviously it is still not enough. As renewable energy we are still in need of new resources to compensate our need and minimize the usage of petrol. The OSMOSIS is the new potential renewable energy source that we can add to our list.

On Tuesday, 24 November, her Royal Highness Crown Princess Mette-Marti of Norway opened in Tofte (60kms away from the capital) the first

electrical central in the world that works on the OSMOSIS phenomenon. It is not shocking to see this very first step taking place in Norway. Indeed, the Scandinavian countries are becoming (true) leaders in fighting against climate change, just as in optimising new technologies for the world to benefit from them.
 

What is OSMOSIS? How does it work? Is it simple?

Huge amounts of energy are set free when freshwater meets salt water, such as when a river runs into the sea. This energy can be used to generate power through osmosis.

Its main principle consists in filling 2 tanks; the first one with sea salt water and the second one with freshwater. Both tanks are connected with porous films. Both volumes will try to combine in order to have a balanced salinity rate. The film’s role is to allow the water molecules to go towards the seawater tank which attracts the freshwater, and to prevent the salt molecular particles from going through. A natural overpressure is created. A pipe is used to unclench an electrical turbine.

The idea of using the osmosis to generate power popped up in the 1970s. Back then, the membranes were not reliable yet and the energy prices were so low that no one found it a good investment. Nowadays however, this new technique is an excellent bargain for the renewable energy production :

• it is based on two natural sources (seawater & freshwater),
• it is not influenced by the weather forecast (sun path, wind...),
• it has a 100% neutral influence on the environment, and will be applicable everywhere a flow of water meets the sea, in almost all the countries around the world.

In Tofte, the plant is integrated in a humid big apartment volume. On the first floor we can see both fresh and salty water entries. The salty water is drained from a nearby lake. Sixty very slim membranes (Named modules) are (being) enrolled, each one being divided into parts of 30m2, thus looking like a gas tank. Both types of water enter separately in the modules where they will be exposed to the OSMOS process which increases the salty water volume at the exit. The decanted extra liquid is then pulsed into a small turbine.

Statkraft engineers are looking forward to the near future. They are aiming in 2015, to build a commercial osmotic power plant that will produce 25 Megawatts (MW), 1000 times more than that of Tofte. To achieve this goal, 5 million square meters of membrane will be implemented. An optimisation of the membrane type, efficiency, and sustainability are a must.

All the elements are in our hands. The planet resources are known. Research founds have been asked for. Now, it is our duty to find the best parameters for the combination of the different elements to achieve a better sustainable renewable energy.