Tidal Power – The Next Green Energy Source?

Greetings, dear readers. I read today on TriplePundit, a site about green business, about harnessing the tides to generate electricity. I’ve heard of this for some time, but never investigated in depth until today (and I’ve been known to pontificate about energy policy). Obviously, locking our electrical generation to something as reliable as the moon’s orbit of the earth is an idea with some appeal, but here’s the specifics, based on what I read in the article. Take your peek at it here.
There are three kinds of tidal power plants:

• Tidal barrages are dams that are closed aroudn a high tide, and channel the water back out to the sea via a turbine, which does all of the generation of electricity.
• Tidal fences stand in the path of the tide, and water flows through the turbines mounted in the fence. (I wonder if there are any gearing issues with making sure flow in both directions generates power?)
• Tidal turbines are esentially self-contained turbines.

There’s a number of edges and flaws to this power generation scheme. On the plus side:

• It’s quite renewable – so long as there’s a moon in the sky.
• Tidal power is almost carbon-neutral, as the only CO2 the tidal power plant would create are during manufacturing, construction, and maintenance, otherwise, the electricity generated is emission-free.
• Power output is efficient and predictable.
• The tidal plant could provide a measure of protection against tsunamis and the like.

However, no generation solution is perfect – there’s some hang-ups, too:

• Tidal power is expensive to implement.
• Only sites with sufficient tides would be suitable, and these are often geographically remote.
• Generation is non-continuous, as it only occurs when the turbines are being moved by the tides.
• There is an environmental impact on marine life as well as water and salinity balances.

All in all, this was an interesting read – the idea of harnessing natural forces for humankind’s ends are of great appeal to me.