Engineering students build wind-powered water heater

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http://www.capitalpress.info/main.asp?SectionID=67&SubSectionID=790&ArticleID=27635&TM=9767.171

CORVALLIS, Ore. - A team of engineering students from Oregon State University, inspired by a late professor's rudimentary sketches, has designed a working prototype of a hot water heating system powered solely by the wind.

The students believe the technology, which uses magnets, a copper plate and plenty of ingenuity, has the potential to birth a new company and ultimately make an impact on the way the world heats water, especially in developing countries.

...

The magnets spin in close proximity to a copper plate, which becomes hot due to magnetic resistance. The heat is transferred from the copper plate to water being pumped through coiled copper tubing that is mounted against the back of the copper plate. The turbine could also be positioned in a stream where moving water would turn the array of magnets, the students said. And once the water is hot, the wind turbine could be used to generate electricity, or the hot water could provide additional passive heating such as radiant heat for a home.

Site is a bit jumpy due to some weird AJAX coding, but worth a read. For those not familiar with magnetic braking and heating, this might be a good article:

http://en.wikipedia.org/wiki/Induction_cooker

While heat is much cheaper than pure electricity, there are good reasons why wind power for space heating can be considered -- the engineering requirements are much, much simpler, you don't have to know anything at all about electricity to do a good DIY job, and heat is generated exactly when you need it -- when crosswinds cause drafts. The only real problem is the plumbing -- getting that heat from the turbine back into your house.

[lvx35]

1. Wow. Does it talk about what it can do practically?

Like how much water can a home size unit heat to bath tempuratures?

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2. Unfortunately, no.

I expect the efficiency of kinetic captured energy to heat is pretty close to 100%. The savonius they use has a low wind capture efficiency if not shrouded like the tmawind ones (those are 30%, this one is probably about 12-15%) The size of turbine needed would have to be bigger of course than the model unit they have there in the picture. For ones small enough for rooftop mounting my best guess is you'd need 2 or three -- say one per resident? Wild guess there, though and of course dependant on wind speed.

[lvx35]

3. Oh, I wish I knew...Damn! Wouldn't a solar/wind powered hot tub...

...be the absolutely MOST pimpin' thing you have ever heard of?

[catnhatnh]

4. Much of the wasted energy on earth is water energy....

...which happens in many places and 24/7....wind is nice,but ephemeral and sun converts cleanly but can be obscured....but the rivers run always to the seas and until the earth herself ceases the tides will rise and fall...I'm a hydro guy and always will be.....

[hunter]

5. I saw something like this maybe twenty-five years ago.

It was a more of conventional multi-vaned water pump style turbine on a tower connected to two pipes.

From an engineering standpoint I think a conventional electric water heater and a windmill with a custom designed alternator would be easier to install. For a regular water heater you'd want an alternator that raised 240 volts at maximum rated wind speed. The nice thing about electrical resistance heating is that the voltage, currents, and frequencies are not at all critical once you've got the maximum power rating of the turbine.

[Kolesar]

6. A resistive heater could get *all* of the energy out of the current

That rotating system has to have *some* amount of mechanical losses. Not to mention that the resistive heater would be cheaper.

I would just put a black barrel of water in the sun for hot water and use the juice* from the turbine to run a PC, refrigerator, or furnace blower.

*electricity