The virtues of vertical
The turbines we’re used to seeing have horizontal axes; like windmills, their blades spin between parallel and perpendicular to the ground. As noted above, these turbines have gotten huge, because bigger means better when it comes to efficiency. Despite the energy that’s lost in transport and conversion, large turbines are still worth our while.
But there’s a limit to how big horizontal-axis turbines can get, and once we reach that limit, we’ll need a different solution. of Cranfield University’s Offshore Renewable Energy Center thinks vertical axis wind turbines (VAWTs) are the answer.
“Vertical-axis turbines…experience a constant gravitational force, always in the same direction,” he wrote. “Without the stress of holding up 80-meter metal blades by one end, VAWTs can potentially become much larger.”
Since their rotation doesn’t take up as much space as horizontal-axis turbines, he adds, vertical turbines can be placed closer to each other in a wind farm, meaning more electricity can be generated in a given area.