Yes, your premise is correct Icfbound...I try not to spend too much of my time on what I consider to be lost causes...

Most people know that efficiency over unity and perpetual motion schemes are NOT possible. A good HS student could show using the basic conservation of energy principal that a constant high pressure (or flow rate) pumping system will require more energy to operate than a lower varying pressure (or flow rate) pumping system (e.g., bladder tank system) for delivering the same quantity of water. It is only when you compare a badly designed and inefficient system to the CSV scheme (i.e., cherry picking data and obfuscating pumping head and flow rate) that you can show the opposite.

If your really want a constant delivery pressure (or flow rate) system, you will just need to use more energy to make it happen and you will have higher pressures in your pipe system which may be detrimental if not first considered and addressed than if you just used a typical bladder tank system. There is nothing wrong in doing that, just know the reality of what you are doing. And also just know that you can always design a bladder tank system that will cycle your pump to whatever minimum level you desire (e.g., even once a day, week, month or year) by simply increasing the tank capacity as required. And please be sure that the minimum bladder system pressure (or flow rate) is adequate for all your needs as you will spend more continuous time both there and at the maximum bladder system pressure (or flow rate). And the bladder tank system requires more space.

Again, it is always best to have a knowledgeable person properly design a pumping system to satisfy the system requirements at maximum energy efficiency and pump life. Please don’t just swap out pumping systems components without first applying this knowledge or you will likely regret it.

Your premise is not correct ifcboud. Listening to someone who doesn’t know anymore about pumps than sailawayrb can make it even worse. It seems I spend a lot of my time on lost causes, but I do it because I still feel you guys are smart enough to figure this out, eventually. A good high school student could easily learn to read a pump curve, I don’t know why you guys cannot.

Every pump should be “cherry picked” for the application. That is what makes the most efficient pump system. But most people don’t know how to do that. They just add a VFD to make any size pump do any job, but at the cost of lower efficiency.

I know people get angry when I correct them, but you would think I was the one who told them Santa Claus isn’t real. Lol Although VFD’s can save energy with positive displacement pumps, air handlers, conveyor belts, and the like, a VFD always waste energy with a suction lift or constant pressure application and a centrifugal pump. The static head requirement and losing head by the square of the speed is the problem they can’t overcome.

I also fully agree you need someone knowledgeable to design pump systems. But finding someone knowledgeable means finding someone who can do a high static head system without using a VFD. If they don’t know how to “cherry pick” a pump to do that, they won’t know a VFD increases the energy consumption either.

Oh yeah, have you found a single pump company that will disallow a warranty for using any kind of pump control valve yet??? I didn’t think so! Which means everything else you say is suspect as well. See this link
https://vimeo.com/248374685

I realize this post is quite dated, but I thought I would reply for new users. Installing a VFD on a well is probably not going to save you any money, because the well itself causes a lot of static head which the pump has to overcome. Without getting too far into the weeds, I suggest that a storage tank and pressure switch is probably the more cost effective option, and a VFD is not.