Mid-Size Turbines a Have Big Advantage in Output Relative to Visual Impact

By Paul Gipe

No, that’s not mere click bait. That’s the argument Geoff Henderson makes in a provocative paper on wind turbine size and the landscape impact of wind turbines.

Henderson is founder and managing director of WindFlow, a manufacturer of a mid-size wind turbine in New Zealand. Yes, New Zealand. Most people in the wind industry wouldn’t know that he and his two-blade wind turbine even exist. But exist he does and he doggedly continues to promote his product despite overwhelming obstacles.

Henderson knows wind energy and can usually be counted on to make a solid case. I was reminded of this when I reluctantly agreed to read his short paper arguing why medium-size wind turbines—such as he manufactures–are easier to integrate into the landscape than multimegawatt machines.

His argument boils down to an observation brought to my attention decades ago by Paul White, then an intern and now himself a longtime veteran in the wind industry. White pointed out that the land area required for a wind turbine is the same regardless of the turbine’s size. Because of the spacing required between turbines, the bigger a wind turbine, the more land area required so the land area per MW or kWh remains relatively the same. White made a spreadsheet for me that showed how this works and I still use it today. I won’t elaborate on this point further; you can read Henderson’s paper where he explains this.

Elsewhere I’ve argued that bigger turbines only offer spacing advantages, relative to smaller turbines, where you can only install one or two turbines. Thus, a German farmer who is permitted to install only one wind turbine will opt for the largest he can to maximize his revenue. However, in an array of multiple machines, bigger doesn’t mean more optimum use of the land.

Henderson goes on to point out that bigger turbines, because they are taller, are visually more obtrusive than smaller machines. Again, he makes his case better than I can.

See Mid-Size Turbines a Have Big Advantage in Output Relative to Visual Impact by Geoff Henderson, WindFlow