It’s an 18kW Generac. Air cooled through as the water cooled was quite a bit more.Is that an ATS?
If so it looks fancy.
What's right under it to the left of the surge protector that looks like a little meter base?
Next to the main is the disconnect & inverter for the PV system on the house. Came with it when I purchased the house but I had to rewire it & replace the inverter as it had a burnt terminal at a lug.
Here’s the garage with the new sub panel & hidden xfer switch as well as the gas line run(was still a mess from moving everything around for the work):

