<story><title>Which way a wind turbine turns might not seem to matter, but it does</title><url>https://www.economist.com/science-and-technology/2020/05/16/which-way-a-wind-turbine-turns-might-not-seem-to-matter</url></story><parent_chain></parent_chain><comment><author>floatrock</author><text>Fun-fact pot-shot time!&lt;p&gt;The first paragraph states the thesis that there&amp;#x27;s something about wind patterns in the northern hemisphere that make windmill directionality important.&lt;p&gt;The first paragraph also says:&lt;p&gt;&amp;gt; It is convenient to have all clock hands turn in the same direction, but it is an accident of history which direction that is.&lt;p&gt;Clockwise is not a random coin-flip of history. Ironically, clockwise is clockwise &lt;i&gt;also&lt;/i&gt; because something about the northern hemisphere: the shadows on a sundial move clockwise in the northern hemisphere, so when europeans first started making clocks, they continued the sundial convention!</text></comment>
<story><title>Which way a wind turbine turns might not seem to matter, but it does</title><url>https://www.economist.com/science-and-technology/2020/05/16/which-way-a-wind-turbine-turns-might-not-seem-to-matter</url></story><parent_chain></parent_chain><comment><author>scrooched_moose</author><text>Preprint of the full paper here:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.researchgate.net&amp;#x2F;publication&amp;#x2F;338882074_Should_wind_turbines_rotate_in_the_opposite_direction&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.researchgate.net&amp;#x2F;publication&amp;#x2F;338882074_Should_wi...&lt;/a&gt;&lt;p&gt;It&amp;#x27;s cool work. Some things I&amp;#x27;ve picked out from a quick skim:&lt;p&gt;- Only the downstream turbines gets a boost, cutting gains of a pair in half*&lt;p&gt;- The boost only occurs at night, cutting gains approximately in half again.&lt;p&gt;- Veering winds only occur 75% of the time&lt;p&gt;This already cuts the gains from an ideal 23% to roughly 4.5% real world.&lt;p&gt;I don&amp;#x27;t see any treatment of incoming wind direction - it appears to only consider pure West to East wind with turbines precisely aligned with the wind. I suspect the effect would disappear as the wind shifted from other directions. While wind is generally westerly in the US, it varies a lot hour-to-hour.&lt;p&gt;Combine this with the above and I&amp;#x27;d suspect real-world benefit is in the 1-2% range, at which point the added complexity of maintenance and production probably cancels out the benefit.&lt;p&gt;Not a knock on the research, because it is great work, but it is incomplete.&lt;p&gt;*This may be unfair, as it&amp;#x27;s unclear what affect multiple in a row would have. But the power production of multiple turbines in a row when the wind is blowing precisely parallel to the row drops off pretty quickly. Commercial turbines are something like 45% efficient these days, so turbine 3 only has ~30% of the original power available.</text></comment>