The heat pump compressor requires a hefty generator.
But if propane or natural gas are available one can use a gas furnace as backup instead of electric heat strips.
In the latter case a small generator can be used to run the blower fan/thermostat.
said by Zorack:
Are there any electric heat pumps out there that will work for backup heat if the power goes off without using a generator? I don't think I've ever seen this question before and I'm pretty sure the answer to that is no. I'm just curious about this that's all.