December 5, 2013
Power Can Be Hot
I have never liked the heat all that much. I find the winter months, snow aside, to be a much more comfortable time of year than summer. After all, you are always able to bundle yourself up to greater and greater degrees when you are cold, yet there are only so many layers you can take off before it starts bordering on public indecency. Coming from a state renowned for its unpredictable weather and odd shifts in temperature, this has always been something I have had to deal with. In summary, I have always disliked heat. Of course, leave it to a source of heat to provide us a potentially renewable source of energy within the next few years. As much as I might not like the higher temperatures, I cannot deny how useful they can be.
It is through a process called thermionic conversion that we are able to convert heat energy into electricity. This is the principle behind using fossil fuels and solar panels to fuel our generators, and for almost as long as we have known about it, researchers have studied how they can potentially develop a thermionic generator able to produce the electricity conducting heat without the need of nonrenewable fossil fuels or the light of the sun. Thus far, there has been little success. Hopefully, that may soon change thanks to a new design called the thermoelectronic generator. These generators use the difference in temperature between a hot and cold plate to create electricity. Electrons evaporate from the hot plate, then are drawn to the cold plate where they condense. The resulting difference between the two plates in terms of charge creates a voltage that drives an electric current all without the need for moving mechanical parts. Previous versions of such a device have all suffered from what is called the “space-change problem,” according to solid-state physicist Jochen Mannhart of the Max Planck Instutite for Solid State Research in Stuttgart, Germany. This occurs when the negative charge of the electrons that leave the hot plate repel other electrons that are also trying to leave it, which then interrupts the current. Mannhart and his colleagues have discovered a way around this problem by using an electric field to draw the charge of the electron cloud away from the hot plate, allowing the electrons to travel over to the cold plate and complete the current. Thus far, they have been able to reach efficiencies using their thermoelectronic generators of around 10 percent, though predictions state that they should be able to reach upwards of 40 percent.
The road to cleaner, renewable energy is rife with new innovations, and thanks to them our future is looking brighter and brighter, literally. What projects like this one need now is for big business to realize the possible potential of such a device and test its practical applications. Cutting ourselves off, cold turkey, from fossil fuels cannot happen. We simply are not able, at this point, to fully separate our need of fuels with our eco-friendly ideals. What devices like the thermoelectronic generator allow us to do is more gently wean ourselves off of them, showing us that there is a better, cleaner way we can still have all of our toys and play with them too.
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