Valveman
Platinum Member
You really need a diaphragm pump or helical shaft type pump like the RPS in the above link to make it work at any RPM the sun will give it. The problem with diaphragm type pumps is they need a new diaphragm as often as you need to oil or work on a windmill. In the 60's they had a helical shaft submersible we called the Peerless Wiggle tail. Lol! The problem with the helical shaft is its hard to balance and hold with a bearing. So, it knocks the bearing out in the top of the motor often. You can get solar pumps with regular centrifugal impellers that will last a long time. The problem with those is centrifugal impellers need a fairly high minimum RPM to work at all, which limits low producing solar hours. Dealing with gophers and 30 bucks a month for a meter is worth it. Even with heavy use making your own electricity won't pay off, but I am afraid it is fast becoming more dependable than the grid.