The suggested link above even it an old post(Actually, it's edited/updated last Aug 2019) it is still an excellent start to read if you are planning to start a mining farm.

There's no ongoing development except for miner if you want to make a good profit try to check which miner is profitable nowadays.

You can use this https://www.asicminervalue.com/ to find which miner is profitable nowadays. Since you have a free source of electricity from your environment, mining with any miner will make you profit.

Try to check the latest miner from Bitmain, which is Antminer s19 Pro; this is the only miner that has the highest SHA256 profitability nowadays for free Electricity.