Been looking at backup/standby generators for decades. I know Generacs do just fine, but I'm looking at liquid cooled and at least 24kW with a load balancing transfer switch.

I don't have my power requirements in detail, but I have three separate air conditioned areas, with three compressors and air handlers. This will mainly be for storm backup and just general fussiness of the power grid in our area.

Really, I would like to hear those who have had experience with 24kW or larger standby generators. Did you regret not getting a larger more powerful generator or was a solid unit (appropriate for expected load) with load balancing switch do it for you?

One thing I haven't read about is if my natural gas service needs to be upgraded. Tips, tricks and general advice for all of this would certainly be appreciated.

I have a 20KW propane Generac at home, an 18KW natural gas Generac, and a 75KW natural gas Cummins at work.   And then I have a dual fuel Honda EU2000i, a dual fuel Honda EU2200i, and an OLD gasoline HF 8KW with a Honda engine.  

The large generators are awesome for short outages.   We have had medical staff on hand at home that had no idea the power was out.   The problem is that they use A LOT of fuel.   Our 20KW would burn more fuel in 24 hours than AR-Jedi used in his entire 12 days without power in his dual generator approach.   We have had enough natural gas shortages in our area that this causes me concern when running the office at work on generator power.   So that is one of the good and bad sides of running propane.   You are responsible for your fuel supply but you are responsible for your fuel supply......    I have a 1K propane tank full.   It is between $2,000 and $3,200 worth of fuel depending on the price of propane at the time.  On the 20KW it would last between two and three weeks.    That is about $150.00 per day in fuel.   We have had outages that lasted two weeks in this area. We keep the smaller generators around to extend the fuel and to allow multiple types of fuel.   If propane is hard to get then we can run gas.

What size meter do you have? If it's the standard 175-250 then 100% absolutely yes you will need a 425 upgrade and a new stand at a bare minimum.

You really need to call your utility and talk to one of the ''engineers'' who needs to do a load study which will consist of adding all your NG appliance BTU outputs and your new generator loads up and sizing it to handle the max amount. Even a on demand gas water heater can jump it very significantly. [2-3 normal furnace loads right there for most and they tend to be VERY unforgiving on pressure drop when they fire]

You will need Nat gas upgrade, def a larger regulator if not a larger line.

Are you really sure you want that big of a genset? That is going to burn a lot of fuel.

I understand you have 3 AC units, but do they all need to run at the same time? Automated controls can be integrated into the low voltage thermostat wiring so that they only run one at a time while on generator.

OP,,You won't need a "new" natural gas supply line. The Natty gas Kohler I have (30KW) DOES require a different regulator as the pressure required to run it is different than appliance, heaters etc. inside your home. Be SURE and get the 1800 rpm varian as they are bullet proof compared to the 3600 rpm units. MUCH quieter. So quiet that you can't hear it from inside the house.

Thanks, can you give me an idea of your load usage? 30kw sounds like it might be in my range.