Submarine farms could help EU face climate change threat

HAMMERFEST - Norwegian firm Statkraft says subaquatic sea tide-harnessing machines could in future provide 3 percent of the EU's electricity, as new research shows rising CO2 levels are causing epochal changes in the Arctic seas.

The floating machines - 40 metres long by 15 metres wide on the sea surface - are to work by using tidal water movements to turn submerged turbines providing 3 to 5 GWh of electricity per year.

Statkraft estimates the technology could one day supply up to 100 TWh of power for the EU, with Germany, the UK and the Netherlands already expressing interest in the project.

"They are commercially competitive with wind power," the firm's senior advisor Bjornar Olsen told press in Tromso on Wednesday (31 May). "But unlike wind, tidal movements are constant. The waters only stay still for two to four hours each day."

The low visibility of the units could also help locals swallow the sea farms, which have a smaller impact on the landscape than the 120 metre-high windmills already towering over some beauty spots in the UK and Norway.

Statkraft's first prototype tide farm is set to start work in the Tromso region fjords later this year, with commercial production planned four to six years down the line, Mr Olsen added.

Further north in Hammerfest, small local firm Hammerfest Strom has already been powering over 20 homes with a tidal turbine fixed to the sea bed since 2003.

Osmosis

Meanwhile, EU funding is also helping Statkraft develop "osmotic" hydro energy plants, which operate by harnessing pressure generated when heavy sea water is mixed with fresh water in large banks of metal drums.

With prototypes due in 2010 and testing to be completed by 2015, future osmotic power plants could generate up to 250 TWh of electricity for the EU, the company projects.

The growing political and commercial interest in CO2-clean energy technology comes at a time when the scientific community is becoming increasingly worried over human impact on climate change.

Nature magazine on 31 May published research showing that 45 to 50 million years ago the Arctic was free of ice with sea water temperatures of 23 degrees Celsius - the same as in the Mediterranean Sea today.

From white to blue

But due to a combination of natural and human factors, the Arctic region will on present trends again become ice free in just 100 years, Norway Polar Institute marine geologist Nalan Koc said.

"From being a white ocean it will become a blue ocean," she indicated. "If we do nothing, CO2 levels [and average global temperatures] will skyrocket."

The sudden jolt could see low-lying countries such as Bangladesh inundated, while the Arctic's iconic polar bear, which feeds on the edges of sea ice sheets, would also face danger.

Ms Koc explained that the earth has naturally warmed up and cooled down again in 100,000 year glacial cycles over the past 400,000 years.

"The problem is that if we suddenly accelerate the changes, we don't know what will happen. It could be chaotic," she said.