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My name is Nick. I am a chartered civil engineer with a Master in Renewable Energy. Most of my renewable energy field experience has been in small scale solar pumping. My knowledge of hydroelectricity is theoretical rather than practical. I do have some experience in developing ground water schemes, plus a number of missions to Iraq. Introductions over, here goes....
If I understand correctly you plan to 'dig' a 250m well on top of a hill, presumably then raise this ground water to a header tank at the top of the hill, releasing it to drive a Pelton wheel. You are correct in your notion that you will defy the laws of physics if you are successful in this. The energy required to lift the water to the top of the hill, will be much more than the energy generated from releasing it, due to common sense compounded by the efficiency losses in an albeit high efficiency system. Furthermore - digging a 250m well is no small feat, a drilling rig will be required, plus a well lining installation and an expensive submersible pump.
Pelton wheels are suitable for situations where there is either a natural large head of water, such as a river in in its youth. Or on a large hydro-scheme, with a high impoundment dam.
Based on the information that you have given me, I would recommend pursuing solar PV as an option. Modern PV systems are easier to operate than small hydroschemes. When I was in Southern Iraq about 8 years ago, I saw some solar PV arrays in remote rural areas, being used by villagers to operate borehole pumps. I am pretty sure there would be a good local solar contractor available who could do a design and build. You could build into the contract a clause to train a local engineer on operation and maintenance, as well as periodic maintenance. If not - get a specialist solar NGO to do it.
A few other things:
- You could consider decentralised PV systems - e.g. mount panels on individual houses, so householders can keep panels clean
- Is there a prevailing wind direction - can you use the wind shadow of the hill to mount the panels to reduce dust cover?
- Consider using evaporative cooling systems rather than conventional chillers. They use much less power than pressurised refrigerant systems. Very common in shops when I was working in Kurdistan a few years back.
Good luck, would love to hear how it goes,