Complicated question, complicated answer. I have lived off well water for more of my life than not, in Texas and in Kansas. Find a good well guy in your area -- the older the better. If he's not over 50, don't trust him. Practical reality. Folks that haven't had to live with them don't know them, and there are few that have had to live off a well that are under 50.

You don't say how deep your well is. It also looks a though your well is set up with a submerisible pump, a pressure tank, and no reserviour. So you have some down-hole rigging to deal with.

A good old fashioned cast iron hand pump is only good to about 20 feet down or so, and if you don't use it all the time, you will have to prime it. The 'leathers' as we used to cal them, the gaskets tht act as valves, dry our and lose their seal. Nowdays they are neoprene.

But those hand pumps have a stroke of only 8 to 12". A windmill can easily have a sroke of up to 4 feet -- 2 feet is average. If you are serious about keeping your well serviceable, and about a no-power option, get a windmill. Get a water tank to hold the surplus, and if your aquifer is good, water your grass or your stock with the surplus.

You cannot swithch readily between an electirc submersible pump and a hand pump or windmill, becaue they all depend upon different downhole gear. You'd have to pull the pump and drop in the rods to swith over to a mechanical pump. I've done. You don't want to. Pick one: electric or mechanical.

And, please, please get your water tested. Fecal coliform is an ever present threat, where you would least exepect it. At our home place there are 3 wells within 250' of each other. 2 are good, one was shut in [made non-producing]. It is the well nearest a septic tank and stock pens, and despite a 250 foot difference in depth, it got contaminated, due to very permeable soils.

I live in San Antonio now, which supposedly has be best water [Edwards Aquifer] in the US short of New York City. I miss the taste of the well water. Water should, I think, have a taste to it.

Sorry for the long post. Got me to thinking back.