They are using solar and micro-wind turbines or something, apparently their energy expenses are super low.

It's in an old freestanding bank building, security isn't an issue, I just want to know what the pitfalls are for co-locating other than money.

Oh, and the $500 is paid annually.

I'm looking at a colocating service in Texas that charges $500 a year per AntMiner S9.

This would save me about $300 a year per miner.. seems like a no-brainer, what are the downsides?