Pump Efficiency: Why This Critical Metric is Often Ignored (and Why You Should Care)
Today, we are discussing pump efficiency—an incredibly important term that dictates how much value you get from your pumping systems. We will define what pump efficiency is, explore why it is so crucial, and reveal a surprising reality regarding how pump operators currently use this information to improve their operations.
Check the video here...
Understanding Pump Efficiency
Imagine you have a motor connected to a pump. To move the required amount of water, you must input energy from the motor to rotate the pump. Let’s say you input 100 units of energy into the system. Shockingly, the pump only uses about 80 units of energy to actually accomplish the job.
This means 20 units of energy are not used to do the work the pump was hired for. Where does this wasted energy go?
- Friction: Some energy is consumed by friction in internal operations, such as in the bearings.
- Internal Flow Loss: The impeller, which is responsible for moving the water, often pushes the water in directions other than the intended one. Not all of the impeller's movement is dedicated to pushing the water forward.
- Impeller Inefficiency: The impeller itself may simply not be efficient, meaning it is not effective at doing its job.
We define pump efficiency as the relation that exists between the power used to move the water and the power that you fully put into the whole system to make that happen. Based on our example, the pump's efficiency would be 80 divided by 100, resulting in 80% efficiency.
Why Efficiency Is Highly Tied to Finances
Efficiency is critically important because you are paying money (dollars or euros) to push or convey water. If part of the money you are putting into the system is not fully used for the job, you are wasting funds.
The simple rule is this: the lower the efficiency of your pump, the more money in excess you have to pay to do the job. Therefore, efficiency is fully related to money.
This financial relationship makes efficiency a key decision-making factor when selecting a pump. When designing a system to move water from point A to point B, designers use the criterion of choosing the most efficient pump available. Everyone tries to save money by using the most efficient equipment so they do not spend as much on energy.
The Global Push for Higher Efficiency
The sheer magnitude of energy consumption by pumps makes efficiency a global concern. It is widely known that pumps are one of the highest energy consumers in the world. In some industries, up to 40% or 50% of the total electricity consumed by the company is attributed to the pumps.
To minimize this consumption and slow down the rate of electricity usage, regulatory bodies have stepped in. The European Union came up with a resolution that practically forced manufacturers to design and produce more efficient pumps. Similarly, in the United States, approaches were taken to encourage manufacturers to increase the efficiency of their pumps to reduce energy consumption.
The fundamental takeaway is that the highest the efficiency of the pump, the less energy it consumes.
The Surprising Reality in Day-to-Day Operations
Despite all this focus—manufacturers are compelled to produce more efficient pumps, and designers select the most efficient model for the system—a shocking reality exists once the system is in operation: operators often do nothing with that efficiency information.
Pumps are mechanical equipment, and they will naturally deteriorate over time. As they deteriorate, efficiency will go down. When efficiency drops, you inevitably spend more money to perform the same job.
However, pump operators generally do not follow the evolution of the efficiency. If you ask them whether they measure pump efficiency, many will simply respond that the pumps are "working fine". The vast majority of operators do not follow this simple, yet critical, indicator.
Are you on the team that says, "I don't care about pump efficiency," or are you on the team that recognizes this simple indicator affects your operations and finances? If you are interested in discussing the life cycle costs for pumping systems, further resources are available.
Dr. John Bruzzo