Tony Trewavas: Think small and out of the box and wind works

THE Scotsman’s recent editorial, “Green ambitions left high and dry” was a necessary reminder of the unreliability of renewables.

But the conclusion that the target is unachievable is only correct if you follow the “conventional wisdom” that wind farms must be constructed from 100-metre high, propeller-style turbines. Because of interactive turbulence, each must be separated from its neighbour by eight to ten rotor widths.

These wind farms are very inefficient collectors of wind energy and increased turbine height supposedly accesses higher wind speeds to counter the inefficiency. However, large turbines pose difficulties in engineering and maintenance, require more land area, impact badly on landscape and kill more birds and bats.

Scientists at the California Institute of Technology have successfully challenged this “conventional wisdom”. By understanding how fish can swim at speed, close together in shoals, while generating interactive turbulence in a medium more viscous than air, they have produced a new wind farm design using only ten metre-high, vertical-axis wind turbines packed close together. The power per unit area collected was 10-15 fold higher than the conventional wind farm indicated above.

If this design had been used here, landscape difficulties would have been marginalised. Five or six of these at uncontroversial sites in Scotland would have provided the necessary electricity, the Beauly-Denny line would be obsolete, carbon emissions minimised and the blight now spreading across Scotland would have halted.

The tragedy of conventional wind farm blight has occurred because governments set up a monopoly situation in renewables. Companies that are showered with our money to construct wind farms have no incentive to look outside the blinkers of routine thinking. Instead of attempting to direct progress, this government above all should have remembered the Scottish Enlightenment solution.

Resign yourself to merely facilitating progress, leave invention to those who can imaginatively solve it and leave price to the market.

• Professor Tony Trewavas is a fellow of the Royal Society of Edinburgh