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.