Seawater as renewable energy source?

column week 5

Doing the research for the water-cycle on Texel I found out that al lot of efforts are needed to close the water cycle on the island. The island currently depends on 2 pipelines that are connected to the mainland for its drinking water supply and after the water is used and cleaned it is released into the ditch system that leads to the sea. This means that all water entering the island ends up in the sea.

Our research is now focussing on closing the cycle by using technical innovations to clean and reuse water combined with demand reducing interventions in different scales. New drinking water could be produced by using rainwater and the cleaned used water to close the cycle. However, I think we might also look at an unlimited water source that is literally surrounding the Island: saline seawater. Could this water be used to contribute towards a self-sustaining water system on Texel? Let’s have a short glimpse of what’s already possible.

Production of drinking water out of seawater is of course a possibility. This has been done for more than 2000 years, but is very expensive and energy consuming compared to local sources of fresh water. The technique is only used in places with no accessibility to fresh water such as the Middle East, but not in poor countries since they can’t afford it. Desalination techniques should be further developed in order to be feasible on Texel; drinking water via the pipeline originated from a natural source is still a more sustainable alternative.

But seawater can also be used without desalination. For example, farmers on Texel already started experimenting with saline agriculture. The first crops, saline sea-kale were already on the market in 2008 and developments did not stop there. Farmer Marc van Rijsselberghe now produces a variety of saline crops such as potatoes, onions, roots and cabbages. Who knows what genetic modification can do to make other plant species suitable for saline agriculture. By growing crops with saline seawater, land does not have to be irrigated with fresh water, which would be very beneficial towards a self-sustaining water system on the island.  

What about other purposes of sea water, such as energy production? A very promising “Blue Energy” test facility has recently been opened in the Netherlands, close to Texel.  The facility on the Afsluitdijk uses difference in electrochemical tension between fresh and salt water to produce electricity. This single plant can generate up to 50.000W, and if more plants would be added to this dike alone enough energy is generated to provide all Northern provinces of energy, including Texel.

The US-navy is also working on extraction of fuel from sea water. They already managed to this, but only in small quantities and it took a lot of energy. The techniques are however very promising if they’re further developed.

These few examples show that the water system on Texel can benefit from the sea towards a self-sustaining system. But if techniques will be improved maybe even fuel and energy can come from the sea. Seawater as a substitute for gas and oil, how amazing would that be! 


- Jesper 

Jesper Goorden

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