Why can't we convert heat to electricity directly?

Question

We all know that electricity can be used to generate heat by introducing resistence in its path, however when it comes to generating electricity from heat there is no straight way for that (or atleast I am not awre of one). All coal plants will use water to generate steam that will drive turbines to generate electricity. Same is the case for nuclear power plants. Is there no way for us to generate electricity in one step? Wouldn't that be a lot more efficient?

Answer 1

We do with thermocouples. Spaceships that cannot use solar energy have a plutonium source that generates heat, which is converted to electricity by a thermocouple.

Answer 2

In a sense we already do convert heat into electricity. Ever see those flashing lights that are powered by solar panels. The "heat" from the suns rays are energizing the solar cells and storing the electricity that they generate in a storage battery for use at night or on over cast days. I have seen shows on TV where the entire roof are solar panels to power the house, the only problem is that they do not go into the details.

Answer 3

The technology has not been perfected for large scale power production.

Below is a link to an article about a company (ENECO) that has developed a thermal-electric technology for converting heat into electricity via a solid state wafer.

The typical method of converting sun energy to electricity is via a photovoltaic (PV) module. They typically cost around $4 to $6.00 per Watt, whereas the ENECO modules are projected to cost between $1 and $4.00 per Watt.

Answer 4

do not study %s yet a thermocouple produces a tiny volume of electrical energy from a diverse of temperatures between a "chilly junction" and the nice and cozy measuring element. in case you're taking a set of those, you could make a thermopile which may make an helpful volume. regardless of if there have been some small rigs that produce adequate capacity for a small pocket calculator from a candle flame, the only great scale (and under no circumstances that massive) one is/develop into the instruments put in spacecraft leaving the picture voltaic equipment which used the nice and cozy temperature from radioactive decay on to make electrical energy out the position image voltaic panels to no solid. the disadvantages of having the radioactive middle crash to earth contained in the kind of a failure made them controversial.

Answer 5

The second law of thermodynamics prevents things like this from happening efficiently.

A system which converts heat to work, without any external work would require negative entropy, which is impossible.

Answer 6

There are are ways to directly convert heat to electricity, but the process is not very efficient. You can read a description at: http://en.wikipedia.org/wiki/Thermoelectric_effect