Underwater Wind Turbines

It’s been a scorcher this week in much of the U.S. and Europe. England hit 40.3° C (104.5° F), which is the hottest temperature ever recorded there, while much of the U.S. has baked under temperatures over 100° F, with some places recording temperatures in excess of 110°. Climate change seems to be taking its toll. If you want to read more about what that could mean for our future—and for biblical prophecy—you can read more here: https://dondavidson.net/apocalypse-soon/.

But let’s turn from the apocalyptic to a little good news. In Scotland, they are using the ocean tides to generate electricity.[1]

The tides are caused by the Moon’s gravity tugging on the Earth’s oceans. This causes water to advance into coastal estuaries as the tide rises and recede as the tide ebbs. These tidal movements can be quite powerful—much more powerful than air currents, because water is about 800 times denser than air.

Scotland is home to some of Earth’s fastest tidal movements. Engineers at the Scottish company Orbital Marine are taking advantage of that fact by generating electricity using a 680-ton tidal stream energy generator known as the O2. It is similar to a wind turbine, but underwater. With the O2 firmly anchored in place, the flowing tides spin two turbine rotors to generate electricity—enough to power about 2,000 homes. Bluemull Sound, in Scotland’s Shetland Islands, has six of these monsters. The UK currently gets about 3% of its energy from the tides, but by 2050 they hope to get 11% this way.

Like wind and solar power, this is clean energy. But unlike wind and solar, the tides are constant and predictable. And since water is so much denser than air, the rotors can be much smaller than on a wind turbine (ten meters compared to about fifty-two meters on most wind turbines).

Energy produced by the tides has its limits, since few coastal areas are as well suited to it as Scotland. But if we are to win the battle against climate change, this type of power may be part of the solution.

[1] This blog entry is based in part on the article, “A Rising Tide Lifts All Grids,” in the July 4/July 11, 2022 edition of Time Magazine.