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Submersible Glider Powered By Thermal Changes
An anonymous reader writes about a new robot submersible that uses temperature differences in the sea to power operation for more than twice as long as previous, battery-dependent vehicles. "The torpedo-shaped glider moves through the ocean by changing its buoyancy to dive and surface, unlike motorized, propeller-driven undersea vehicles. To power its propulsion, the submersible gathers thermal energy from the ocean. When it moves from cooler water to warmer areas, internal tubes of wax are heated up and expand, pushing out the gas in surrounding tanks and increasing its pressure. The compressed gas stores potential energy, like a squeezed spring, that can be used to power the vehicle. To rise, oil is pushed from inside the vehicle to external bladders, thus increasing the glider's volume without changing its mass, making it less dense. The oil can be shifted inside to increase the density and sink the vehicle."
and it works brilliantly. Mind, it's not a submersible so it's not quite so cool. it's just a device that opens the window in my greenhouse so that the tomatoes don't get too hot in the summer!
I assume you're getting at the same thing that I'm wondering... how much of an impact does this have on water temperature, currents, etc., if they're trying to call it "green"?
Of course, "green" doesn't mean much, but energy is never free, and taking it from an ecosystem is always going to have consequences.
In this case, we could try to use these, make them popular, and find out that they not only take heat energy from the oceans, but also change currents.
Likewise, we could try to cool the ice-caps somehow, but that wouldn't "counteract" what's happening with global warming; it would a more volatility to the system, with more extreme cold in one place battling more extreme heat elsewhere. The weather system is already too screwed up as it is without that.
And that's the REAL problem with this AND global warming: that we take things, on a massive scale, without any real respect for the damage it causes, or the slow processes that are needed to create what we take quickly. We can barely admit that we're doing damage, let alone facing the fact that the damage cannot be undone easily.
I'm not saying that we shouldn't use wind power, or solar power, or thermal power, or even combustion engines. BUT, we need to every bit of energy we take from the world -- in WHATEVER form -- depletes it, and that the only real solution is to cut back on how much we take.