Maybe anyone doing solar irrigation could add to this thread, I will.
For anyone looking for quick numbers just to play around with, 750 watts is close to 1 horse power, finished product you'll have mechanical looses and piping friction loss and others but just ballpark. At least if you already know your water requirements and pump specs it's easy to figure out how to replace the electric needs with solar. If you know a few numbers I could probably help with figuring some others.