Hi, I have a existing 670 foot well that supplies water to my house and stables/apt.  I want to know what is a cost effective way to add solar power to the existing well/pump to provide me emergency backup if the power goes out.

Thanks!

Posted By Roger Bringmann on 14 May 2010 07:19 PM
Hi, I have a existing 670 foot well that supplies water to my house and stables/apt.  I want to know what is a cost effective way to add solar power to the existing well/pump to provide me emergency backup if the power goes out.

Thanks!

"Cost effective" and "solar" don't belong in the same sentence as "backup".  If you have reasonably reliable power and don't expect to be out of power for many days/weeks, a battery+ inverter solution is far cheaper backup.  Solar is expensive stuff to use just to maintain charge on batteries when there's a grid available. 

Sufficient photovoltaic to pump much water up 670' on an ongoing basis without the grid is going to be expensive.

You can get some batteries and keep them charged with solar, grid power or a small generator. Then use an inverter to power the pump. The problem is that the pump motor takes a lot of power to start and this requires a large inverter (perhaps 6x larger than you might think). You could use a 3 phase pump + a variable frequency drive (VFD) to reduce the startup power draw. Probably not worth it if you have to replace an existing pump.

Or just get a big water tank and keep it filled. Then a small pump can pump the water.

What about a gas powered generator? As Dana1 said if you do not expect long periods without electricity it will work fine.
However there are a few dowsides like the noise and the carbon monoxide.
It will certainly come cheaper than solar power.
Good luck