Tell us about yourself!
Use a solar panel / battery / inverter. Panel charges battery. Inverter changes battery dc to your regions ac supply. Some initial outlay, but then free for life of solar panel or your dehumidifier. I live in tropical north Australia... it works fine.
I wouldn't say it is "laughable" to say it is efficient... if you have an unused 12V solar panel laying around, use that instead of, or in conjuntion with a battery. Use the sun to do the work. THAT'S efficient.
True. It is inefficient compared to a refrigeration unit. And obviously solar would be better being used to power a conventional dehumidifier.However, since i began using Peltiers around a quarter century ago, their prices are now maybe 2% what they used to cost. "laughable" was what i took exception to. Who knows... tomorrow all refrigerant gases may be banned as environmentally unacceptable. And Peltier devices could be mass produced to fill the gap, making them cost efficient.