how to convert heat energy to electric energy?

Question

can we change d heat energy of our environment to become useful electrical energy?

Answer 1

If heat energy is high enough, typicaly burning fuel or using geothermal energy, water can be heated to steam and the rising steam runs a generator to convert it to electricity. Converting lower amounts of heat to electrical energy is probably theoreticaly possible but not cost effective. Heat is a very disordered form of energy and is typicaly lost to some degree with every conversion.

Answer 2

Yes this is not only possible but there will be practical examples of this type of heat to electrical energy conversion on the market in 2008 on latest estimates. The technology is quite old, have you heard of Stirling Engines?

The Stirling Engine was invented in 1816 by Reverend Robert Stirling. It is known as a Heat Pump. Stirling Engines are being designed to be placed at the focus point of a Fresnel Lens, parabolic mirrors, and the heat generated drives the engine. The engine is fitted with a linear generator, this is a generator which operates by a shaft moving back and forth rather than rotating. Go to the following site to see a small Fresnel Lens and the final design of a power generated by sunlight without using Solar Panels.....

http://www.infiniacorp.com/applications/clean_energy.htm

Also investigate the wikipedia site for more detailed information about this fascinating device and its various applications...

http://en.wikipedia.org/wiki/Stirling_engine#Solar_power_generation

I think you'll be impressed with its simplicity and environmental friendliness as the environmental impact is zero, this is because there are no emissions from the engine at all. If you use solar energy to power the engine then there is no fuel use either. A fuel less engine with no harmful exhaust....what a brilliant concept.....a perfect solution for today's energy conscious don't you think??

Happy surfing.... :-) ............

Answer 3

A discussion of this nature MUST include the THERMOPILE! The simplest is two dissimilar metals. Say you spot weld two separate lenghts of copper wire to an iron wire. If you put an ammeter to complete the ciruict, when you heat one end, amps will flow (low voltage) and the OTHER junction will get hot. You can daisy chain TONS of junctions together (which are now made on ceramic substrates) to make a modern thermopile. The current applications range from CPU cooling (because one side of the junction gets COLD as the other is hot when DISSIPATING electric power) to those cute Coleman coolers found in your automotive drink cooler. Thermopiles are DEFINITELY able to reach the very low sub-zero temperatures that mechanical refrigeration has trouble maintaining because of lubricants in the cooling stream and rotating shaft seals.

Another "weird" invention was someone noticed that the exhaust gases of a jet engine could be influenced with an external permanent magnetic field and electric power could be had from ceramic (heat proof) electrodes. This was never really commercially produced and I know of no current plants operating on the "plasma" principle.

One guy mentioned Stirling engines--thats a good way but the power densities are very small, and the working fluid is a gas which has low availability as opposed to steam in a steam turbine.

In Arizona they have fields of mirrors aimed at a collector with liquid sodium which transfers heat to a steam generation circuit which runs a generator off a turbine. When the weather is good, good output is acheived, but the hazards of a molten explosive material flowing at high temps and pressures is somewhat of a headache to manage safely, but somehow they do it.

Heat pumps take energy and move heat from one place to another. If they could run with no energy input, that would be great, but they are parasitic in nature.

Answer 4

Kyle is right, but you asked about THE four devices, not just ANY four devices. Was that a typo? There's really no limit to the number of devices that generate heat as a byproduct of electricity use. And there are far more than four devices that are intentionally used for converting electricity to heat.

Answer 5

There are some thermal applications for heat, however the laws of thermodynamics make it quite difficult to convert heat into electricity. Heat is already a electro-magnetic radiation just below the infrared spectrum.

Answer 6

You use a heat pump - It more or less is an air conditioner working in reverse. But remember, nothing is free... You cannot violate the Laws of Thermodynamics which are (simply put);

Law 1 - you cannot win in this game
Law 2 - you cannot break even in this game
Law 3 - you cannot get out of the game

Answer 7

See what Wiki has to say on geothermal power