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Is there a way to convert radiation from atomic decay into energy directly, the same way we do sunlight with a solar cell?
(lemmy.dbzer0.com)
Couldn't we have a lead box lined with these radiation to electricity converters with a small amount of radioactive material in the center, and have an energy generating device that would last for thousands or even millions of years? Imagine putting the sun in a box lined with solar cells, but on a much smaller scale.
Is there a reason this wouldn't work?
This article has a good breakdown. The biggest issue is efficiency. RTGs are around 5-9% efficient. Standard steam cycle generators are around 30% (see this article ) . You get much more usable energy from fuel used in a commercial reactor vice a RTG.
From the article it looks like RTGs are just converting the heat energy into electricity. Seems like there's a lot unused potential being missed.
Yes, I don't think RTGs are really what you're asking about. It's just a solid state way of turning heat into energy instead of using steam.
Can you ELI5 why the efficiency is so low on the RTGs?
RTGs aren't radioactive-specific, they are just a solid state way of turning a temperature difference into electricity. The better way to do this (at scale) is e.g. a steam engine, which is what big power plants do.
Wow! I think is a subject that Iโd going to occupy my downtime for awhile. Thanks for the in depth info, also relevant username?
They take the waste heat from nuclear decay and convert it to electricity through the use of a peltier device. Those work off of differential temperature and are pretty inefficient to begin with. Unmderated Nuclear decay doesn't produce a lot of heat at one time, which is why reactors use a moderator to increase the power output.