A lot of people throw around 5% efficiency for Peltiers, and it's just not true - it depends heavily on the temperature differential and current vs. IMax. You can (with care) drive them >2.0 COP.
This isn't anything like a compressor or heatpump system, but Peltiers get a bad rap... they move heat really well if you're not pushing them to the edge.
Here's a nice chart. At 10k difference and 0.1 current max, you're over 2.5 COP. https://www.meerstetter.ch/customer-center/compendium/71-pel...
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