A combination of a APC 5000va SURT UPS for the rack + Generac portable 12kw generator + Manual transfer switch + surge suppressor + extended run battery pack
- $1800 - APC UPS w/XL pack powers your 3000watt rack and offers 30m of runtime
- $2400 - Generac 4582 Gas power generator offers upto10hrs of runtime at 7000watts allowing for 3000watts for your rack, and 4000watts for lights, fans, etc
- $300 - Reliance panel type manual transfer switch which routes normal power to your server room and then switches to generator power when you want.
- $80 - Basic surge suppressor to prevent spikes
- $180 - APC Smartslot card with relay controls to initiate shutdowns and turn off non critical loads
- $220 - Breakers, cabling, wiring and misc parts for sucessfull installation
The downside is that this is a manual system and means you have only an hour to roll out your generator, start it up and pull the transfer switch. But for $5k, its a good solution.
Add about another $5000 to make the process automatic.