Hi Zach, cool opportunity. Where do you live in the world (approximately)? The farther North or South you get relative to the Equator, the more shadows you'll get in winter in a walipini. If you aren't growing in the winter, then never mind

Are you thinking the center pivot irrigation line would give you cold in the summer or heat in the winter? It would be neat to build a system to dump greenhouse heat into that cold water line....