27kW? What are you running? A server farm?
We have three central A/C units, electric everything (fridge, hot water, etc.). We could be fine in an emergency with one A/C, fridge and just some lights... we can cook on the outside BBQ grill.
It would be nice to keep the pool pump going during a 3 week outage otherwise the water would probably need to be completely replaced afterwards, which is a cost.