Buy a generator.
That pump is a large circuit, not a small one.
The panels, inverter and battery required to run
it would be prohibitively expensive for a ’stand-by’
system.
The inverter alone would cost more than the ‘genny’.

I went looking and found:

This would be a good place to start. It looks like you will need the solar panel(s) and a voltage inverter so that you will have the AC current to run your pump. Contact them (with the current requirements of your pump) and let them tell you what all you’ll need and the pricing.

See this link:

Good luck.