Comments on: Nova Scotia Eyes Tidal Power in The Bay of Fundy http://www.homelyscientist.com/2007/09/03/nova-scotia-eyes-tidal-power-in-the-bay-of-fundy/ Science at home from a science geek. Sun, 07 Sep 2008 21:22:26 +0000 http://wordpress.org/?v=2.3.3 By: Dave http://www.homelyscientist.com/2007/09/03/nova-scotia-eyes-tidal-power-in-the-bay-of-fundy/#comment-40397 Dave Tue, 04 Sep 2007 14:28:17 +0000 http://www.homelyscientist.com/2007/09/03/nova-scotia-eyes-tidal-power-in-the-bay-of-fundy/#comment-40397 Back to considering the entire system costs for a project, one question which comes to mind is whether this will affect the source of the tides. The tides are caused by the Earth's rotation in conjunction with the Sun and Moon. Thus, tides are caused by the energy stored in the rotational inertia of the Earth. Extracting this energy will affect the rotation of the Earth (as well as perhaps pushing the Moon into a higher orbit). So, the question is, how much rotational slowing of the Earth would such a tidal power project cause, and can we tolerate the slowing of the Earth's rotation? I suspect the answer is that it won't make enough of a difference to notice, at least in our lifetimes. But, in 1000 years, will the length of a day approach 48 hours? Will the Moon be twice as far away? Someone should work the numbers. Dave Back to considering the entire system costs for a project, one question which comes to mind is whether this will affect the source of the tides. The tides are caused by the Earth’s rotation in conjunction with the Sun and Moon. Thus, tides are caused by the energy stored in the rotational inertia of the Earth. Extracting this energy will affect the rotation of the Earth (as well as perhaps pushing the Moon into a higher orbit). So, the question is, how much rotational slowing of the Earth would such a tidal power project cause, and can we tolerate the slowing of the Earth’s rotation?

I suspect the answer is that it won’t make enough of a difference to notice, at least in our lifetimes. But, in 1000 years, will the length of a day approach 48 hours? Will the Moon be twice as far away? Someone should work the numbers.

Dave

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