There are two major factors that afford Hawaii its famously congenial climate: that big, fat temperature moderator known as the Pacific Ocean, and the trade winds. The trades blow from the northeast, though big storm systems can disrupt or even reverse that flow as we saw a week or two ago. But on a typical day the winds around the Big Island appear as they do on this screen snap from a weather app on my phone, taken earlier today:
You might expect from this image that you’d get the strongest and most constant winds at the three vertices where they whip around the edges of the island: the eastern-, northern- and southernmost points. And you’d be right. Today the winds there appear to be blowing at about 15 mph (25 kph), which is somewhat milder than usual. This worked to my advantage yesterday, as you’ll see in a moment.
You might also reason that those would be good places to build wind farms to get some renewable energy action going, and you’d be mostly right about that too. They’ve never done it at the eastern edge, an area called Pahoa that is most famously on the eastern slope of Kilauea volcano. Building a wind farm on the slopes of an active volcano is probably not the best idea, so it hasn’t happened. (That hasn’t stopped people from building homes there though, more than a few of which are currently underneath tens of meters of lava.)
But they have built wind farms at South Point, the southernmost point of the island, and at its mirror image at Upolu Point up at the very north. The South Point installation was an economic failure and was shut down in 2012, though the Mad Max-ish rusting towers, several with missing blades, stand there to this day, as you can see.But the Upolu installation near the town of Hawi has been operational since 2006 and generates over 10 MW of power, enough to power a few thousand homes. It has had some hiccups, including a couple of occasions when it had to be shut down when the winds were too strong.
But the winds were mild enough yesterday for me to achieve a goal I’ve sought for the past year, namely flying my drone over the windmills. So here are a few drone photos of the towers. To give you an idea of scale, each blade is about 75′ (23 m) long.
And here’s a 3-minute video flyover, with a guest appearance of the island of Maui on the horizon at about the 0:55 second mark.
You’ll also notice a small runway. Upolu Airport is a very small general aviation airport that, having little infrastructure and being in relatively remote area of the island, does not see a lot of traffic. When we lived here in the 1980’s it was a favorite place of mine to practice my touch-and-go landings, usually landing towards the northeast into the reliable trade winds.