How Mid-Ocean Wind Farms Could Power The Whole Of Civilisation

Posted October 12, 2017

Writing in the journal Proceedings of the National Academy of Sciences, doctors Anna Possner and Ken Caldeira concluded: "On an annual mean basis, the wind power available in the North Atlantic could be sufficient to power the world".

But extracting efficient energy from wind involves more than putting turbines in the path of gale-force winds.

Though, it is not all about placing wind turbines in the ocean to extract energy.

The study by the Carnegie Institution for Science at Stanford University in California has calculated a wind farm spanning three million square kilometres - roughly the size of India - and based in the North Atlantic ocean could generate "civilisation scale power".

"Are the winds so fast just because there is nothing out there to slow them down?" This limit occurs, because on land many natural and human structures are present which creates friction and this eventually slows down the wind speed. Wind speeds are, on average, much higher over ocean than they are over land, which means that theoretically wind farms in the open ocean could capture five times more energy than wind farms on land. "In the summer such wind farms could merely generate enough power to cover the electricity demand of Europe, or possibly the United States alone".

As a result, more energy is drawn from the atmosphere than over land, which helps to combat the problem of turbine drag.

Possner and Caldeira's sophisticated modeling tools and compared the productivity of large Kansas wind farms to massive, theoretical open-ocean wind farms and found that in some areas ocean-based wind farms could generate at least three times more power than the ones on land. Over land, those winds tend to stay up high, but over the ocean - and paticularly over the North Atlantic - surface warming of the seawater brings them down to within reach of the turbines. This is largely due to the fact that large amounts of heat pour out of the North Atlantic Ocean and into the overlying atmosphere, especially during the winter.

However, this tremendous wind power is very seasonal.

Conventionally, wind turbines are found on land but a new research has revealed that there is enough potential wind energy moving across the Earth's oceans to power the world. However, in this study, we show that considerably higher power generation rates may be sustainable over some open ocean areas.

The study is a "green light" for operators to invest in suitable open ocean technology like floating turbines, said Caldeira, who claimed the main challenge to commercially successful open ocean farms is the low cost of oil and gas.