h a l f b a k e r yAsk your doctor if the Halfbakery is right for you.
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Use a solar oven to provide heat for a thermopile. Attach heat sinks to the exterior sides of the oven to cool the heat-dissipating side of the thermopile. The interior of the oven could be insulated from the exterior by a hollow vacuum chamber. The heat-absorbing side of the thermopile is located
in the interior of the oven and is painted black to absorb heat. Solar reflectors direct sunlight into the top of the oven through vacuum insulated glass.
The thermopile should provide high current, low-voltage DC. The addition of a 555 timer circuit and a high current relay would provide high current pulsed DC to feed a pulse transformer capable of providing higher voltages.
The resulting device has no moving parts to wear out, uses simple existing technologies not subject to patents, and does not pollute.
555 timer circuit
http://www.uoguelph...adgets/555/555.html [normzone, Oct 26 2008]
Buy one at ACE Hardware for $40.
http://www.acehardw...p-36491.html?ref=42 This can generate 750 millivolts. [Amos Kito, Oct 26 2008]
Thermoelectric modules
http://www.tellurex.com/cpowermod.html The thermoelectric modules I was looking at. [kevin_crain, Oct 27 2008]
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it also suffers extreme inefficiency in materials, bulk and weight. Remember that the emissions and energy required to construct a generator are a factor in its overall impact. |
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Using recycled materials for production would lower emissions. |
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//The thermopile should provide high current, low-voltage DC// Unfortunately, it won't.
There's a reference online to a thermopile that can generate two volts:
Hot Side Temp 230°C (450°F)
Cold Side Temp 30°C (85°F)
Load Voltage 2.38 Volts
Current: 8 Amps
Cost: just over $200 |
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Raising the voltage with a transformer reduces the current. A typical portable solar cooker won't manage 230°C, but I found a reference to a 50 meter reflector that meets the specs. Nighttime and cloudy days greatly affect this plan. |
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With 100 of the two-volt devices connected in series and packed in plutomium, you may be able to power an appliance (or charge an electric car). I think you should bury the radioactive thermopile. But I won't bother listing the cost. |
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What [WcW] said .... it's going to need large amounts of refined metals, produced either by smelting (using carbon fuels) or electrolysis (which admittedly could be powered by one of these devices, making it theoretically "self-multiplying"). However, since the units are zero-maintainance and long-lived, the "cost" can be written off over many years. Building one unit "from new" and then using its energy output to somehow recover more raw materials from scrap, waste or taillings would be a good plan. |
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Thermopiles are pretty much Baked anyway, for waste heat (energy) recovery. |
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Anyway, welcome to the HB and a good try for a first posting; rational, well-reasoned, technically practicable. |
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A relay wouldn't last long as a switching element; better to use a semiconductor switch. |
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At a certain point an elegant solution isn't worth the sacrifice in effectiveness. |
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I found some thermoelectric modules that look pretty efficient in terms of material requirements and output, and they are specifically designed for power generation. Perhaps using the oven to heat water and then passing it through a flat steel plate with thermoelectric modules mounted to the surface and heat sinks on the other side of the modules would allow the use of these more efficient thermopiles? |
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Since this device obviously isn't trying to use low emissions materials, why is it any better than your normal solar panel? |
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(Also, a relay involves moving parts /nitpick) |
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Well, it's an interesting idea... I just think that a photocell will do everything it does better, in less space, and with fewer materials. |
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Unless this is some sort of clever satire of photocells. |
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Photocells aren't that efficient. Then again, neither is this. |
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//Also, a relay involves moving parts //...unless, of course, it is a solid-state relay. |
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I think the mirrors reflecting the light into the oven count as moving parts unless you've invented a stationary heliostat. |
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