Solar saviour
Image: The Cyprus Institute
Researchers in Cyprus are designing a piece of uber-engineering that will create 5 million extra litres of fresh water a day.
Will it help prevent farmers’ underground reservoirs from running out?
Technology in pictures
Engineers' story
The team work on a prototype desalination chamber.
Image: The Cyprus Institute
Sunshine island
George Tzamtzis and a team of researchers at the Cyprus Institute have a bright idea to end his country’s crippling droughts…
‘As a Mediterranean island there are two things we have lots of,’ explains Team Coordinator George. ‘Cyprus is blessed with 340 days of sunshine a year and it’s surrounded by sea water.
Concentrated solar power (CSP) desalination will use these natural resources to produce fresh water for the island and for farmers to grow food.’
New technology will improve the efficiency and lower the cost of the traditional central tower.
Image: Abengoa
Fresh water, 24/7
CSP stations that generate electricity already exist. An array of mirrors reflects sunlight to the top of a central receiving tower. This heats water to produce steam, which turns a generator and produces electricity.
‘The central receiver system works well, but at night-time or when there’s poor sun, fossil fuels are used as a backup. We will use a new energy capture and storage technology to produce fresh water using solar power, 24 hours a day and 7 days a week. To do this without relying on fossil fuels we’ll need a reliable and efficient technology.’
Cyprus’s wild and rugged coastline is tricky terrain.
Image: Flickr/celeste33
Coastal conundrum
Current CSP designs need lots of space, so they are built on large, flat plains. Most of the land in Cyprus is taken up by farms and homes.
‘For desalination we need to be near the coast and it’s too hilly. It is a big challenge to get the sunlight perfectly focused on this terrain,’ says George.
‘We have to plan precisely where we put the mirrors high up on the hillside, so they reflect the most sunlight to the receiver.’
Protests show desalination can be a controversial issue.
Image: Flickr/Takver
Salty taste
Once up and running, desalination produces huge amounts of super-salty sea water or brine as a by-product. At large-scale stations it gets piped into the sea. This can harm aquatic life.
‘The brine is up to twice as salty as sea water and this raises the salinity in the area near the outlet,’ says marine scientist Sabine Lattemann. ‘Studies show this can be harmful to sensitive species like sea urchins and starfish.
Years of research means we now know how to reduce the impact for future stations.’
Sea urchins thrive along Cyprus’s coast.
Image: Flickr/Sarsifa
Next generation
The Cyprus Institute’s team will draw on the latest marine research to make sure their design is as friendly to sea life as possible.
‘The station will be away from sensitive habitats. A pipe system that diffuses the brine will dispose of it in areas close to currents. This will dilute the brine quickly,’ explains George. ‘The area of increased salinity can be reduced to less than 200 metres from where it goes back into the ecosystem.’
What the experts think
Cities such as hot Dubai could benefit in the future.
Image: Flickr/the_dead_pixel
Sunrise
If Cyprus’s desalination station succeeds it will be a clear message that CSP technology can produce fresh water. The possibilities are astounding. Gerry Wolff of Saharan solar power initiative Desertec UK shares his vision:
‘The project in Cyprus could pave the way to a great expansion of solar desalination plants to supply small communities or great cities in arid coastal areas and islands around the world.’
For Gerry, this technology is just part of a move towards a better future.
‘It will help provide the fresh water the world needs and move us to clean, green societies of the future.’
Only 65% of the water reaches the soil when sprayed. Dripping the water is better.
Image: Flickr/johncurley
Wrong track?
The Sun provides a clean, sustainable source of energy. But is desalination the best way to fight water shortages? David Tickner, Head of Freshwater Programmes at conservation organisation WWF, doesn’t think so:
‘Rather than turn to expensive solutions like desalination, less waste and more efficient use of our vital natural resource should be the focus. Simple things like drip irrigation or vessels to store rainwater for dry periods.’
Will future generations in sun-soaked dry areas rely on the sun and sea for their water?
Image: Flickr/zz77
Must have?
Nidal Hilal, an expert in water technologies at Swansea University, is certain that just using the fresh water we can get naturally won’t be enough.
‘Every second the world’s population increases by 2.5 people. That’s an extra 80 million people every year who need water for drinking, sanitation and growing food,’ he says.
‘There is no other choice but to tap into the sea to prevent water shortages with such huge increases in world population.’