Electrical energy directly from radiation?

Question

I was curious if there were any studies into taking radiation and converting it directly into electrical energy. My understanding of nuclear energy is that they are basically big steam engines. Is there a way to cut out the steam power and get the energy directly from radiation? Radiation is everywhere- the computer I'm writing on and even the table it's sitting on is giving off some radiation. It would be interesting to know more about this.

Answer 1

Yes. Space probes often do this. Alpha particles are positive charged, and Beta particles are negatively charged, so I believe that either alpha emitters or beta emitters have been used as power sources. I'm not sure about gamma rays

It appears that most of the energy released in nuclear decay is heat, so it is probably more efficient to try to harness the heat energy.

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...Given the initiative, time, and money we can convert most forms of nonelectrical energy into electricity. This includes gamma rays. A direct conversion, though inefficient, is possible through interaction of the gamma rays with an appropriate material that will suffer a loss of electrons through the gamma interactions with it; the electrons can be collected in an electric field and represent a current flow. In fact, most radiation detectors operate on this principle. Gases and solids have been used in this regard. Various semiconductors undergo electron ejection in response to ionizing radiation and have had many applications in radiation detection and measurement. Photovoltaic cells, commonly used in the visible and ultraviolet portion of the electromagnetic spectrum, can also convert gamma ray energy to electron current, but the process is very inefficient in terms of the fraction of gamma energy that ends up as collectible electrical charge.

The process of ionization, which gamma rays are capable of inducing in all materials, is almost always accompanied by secondary processes of excitation in which electrons are excited within atoms, but the electrons are not removed from the atoms. In general, most of the energy transferred to electrons by ionization ends up as kinetic energy of the electron and is lost mostly and ultimately in the form of heat, as is much of the energy of excitation. Thus the direct conversion of gamma energy to electric current is very inefficient. However, it is possible to convert heat to electricity. In fact, when nuclear power plants operate, a small, but not insignificant, portion of the power generated comes from heat generated by the decay of the radioactive fission products that build up in the fuel. The decay radiations include primarily beta particles and gamma rays, both of which produce heat. This heat adds to the fission heat that is used to convert water to steam to drive the turbine/generators. Also, electricity can be generated from heat through the use of thermoelectric generators (e.g., a series of thermocouples, called a thermopile, in contact with a heat source), which have been around for decades and have been used with a variety of heat sources.

Gamma radiation is generally not a good choice for thermoelectric applications because the gamma radiation is very penetrating, and large masses of material may be necessary to absorb most of the energy, likely making for an inefficient arrangement for concentrated heat production and thermoelectric generation....

Answer 2

You could use solar voltaic cells to convert the radiation into electricity. They would need to be very efficient, unlike the current ones, and work at many more frequencies than they do now. I have thought quite a lot about this, we could easily get a lot of power directly from radiation. Unfortunately, the solar cells that we would need would be very expensive and take a lot of research. They would also need to be able to withstand gamma rays and intense heat if used in nuclear power plants.

Answer 3

Possibly you could get some electricity out of a nuclear reactor. But the cost for getting the given amount of energy is much more than conventional electrical generating such as a nuclear power plant.

Answer 4

There are basically 2 practical ways: 1) Focus the sun's rays to make heat, and run a turbine, the same as one would do with any other heat soruce, including geothermal, coal, and nuclear. 2) Use photovoltaic panels to convert a percentage of the light directly into electricity.