I use geothermal as a way to absorb/dissipate the heat. I got the idea from here: https://forums.overclockers.com.au/threads/concrete-slab-wat... Instead though I dug a trench outside that was 4ft deep 20ft long and then buried some pex pipe. As the water flows into the aluminum block attached to the peltier it absorbs the heat and then as it enters the ground it dissipates so when it comes out of the ground of its back at 55F. The water is moved with a 12v pump. The longer the run the better as the ground is not efficient in energy transfer. If its to short it wont cool down all the way.

I thought of trying to use copper pipe with round engine heat sinks attached to it, to increase the energy transfer rate. However it didn't seem like the copper would last long before potentially reacting with the ground.

Simple diagram: https://www.ernstheating.com/wp-content/uploads/2018/01/Erns...