Purchasing bank owned property can be tricky and something that should be done only with care. I like the suggestion of being aggressive with your offer and saving back some money as insurance. Makes sense....
The bank will only sell it "As IS" so once you have made an offer don't expect them to renegotiate in the event a problem turns up. It's best to check as much out as possible prior to making an offer. You may want to have a handyman or contractor or home inspector to look at the property with you to get their advice.
Pay close attention to the big ticket items:
The age of the appliances, hot water heater, furnace should serve as an indicator for the service ability of these items with out electricity.
While making your offer, since there is no power available, tthere is nothing wrong with assuming certain items are faulty and deducting their cost from your offer, to be on the safe side.