It should not use 150W idle. Do you have an Apple Pro RAID card? Fibre channel?
Tried with all peripherals disconnected?
Sleep should be less than 5W.
Maybe, just maybe, some 3rd party controller you have and the driver or PCIe isn't compatible with Lion? in which case you might want to dual boot SL, or just go back to SL until Lion and 3rd party drivers and apps are updated.
It's using 150W when it's not doing anything, i.e., not under processing load, not when it's asleep. It's got a Radeon 4870, which uses 25W all by itself, two internal HDs, two optical drives. The only peripherals connected to this machine other than external FW800 drives are USB. No PCIe cards other than the Radeon.
I haven't slept in way too many hours.... idle 150W is probably norm.
There use to be problems (2008) not being able to come out of sleep.
Issues with running on a UPS that was too small (less than 850W / 1100VA).
Tried SMC Reset once? unplug and press power on button 10 seconds, then release, and reconnect and try to power up?
Multiple members here with 2009s have said that they had to zap pram/nvram in order to get Lion installed.
my money is always to go for clean install and test new OS, migrate data, and keep SL around for awhile. Make sure no conflicts or driver issues.
USB cables and devices (and drivers, like for printer etc) can cause panics, sleep issues, as can FW800 (shorted port, bad cable) so I would only trust them when they have been verified and tested - the problem goes away or not when removed from the system.
I see LaCie and Seagate drives causing Lion issues. OWC are fine.