Interesting on what is considered small. We have 20kW and 12kW on our 65. 80 amp and 45 amp. Basically we can run most things on the 45 except oven, water maker etc if you load watch. But yes 9kW would be too small to be useful for us. We have a 1200Ahr invertor/house bank which we never run just to be quiet. The HVAC would drain it way too quickly. We use it during the day to keep the gensets off and supply the fridge, lighting and nav electronics. Ironically, we run the gensets early morning when the wind drops and it heats up onboard. The gentle hum of the genset and HVAC is the best sound on the world for a beautiful sleep-in. But it's worth noting the difference in boat style is a huge factor. Large slanted glass windscreens impart a phenomenal heat gain into the boat, which HVAC is absolutely required. Almost all of my windows are shaded almost all of the day, and HVAC just isn't required.