Publicly owned water supply and wastewater treatment plants use nearly 70 billion kilowatt-hours (kWh) of electricity each year, about 2 percent of the nation’s total electricity consumption.
This enormous investment in moving and treating water, while critical, also presents a significant opportunity to reduce operating costs. Pumping systems account for about 80 percent of electricity usage in water treatment plants. Many proven strategies exist for optimizing pump system performance, with total energy savings ranging up to 50 percent. Here are eight recommended by the U.S. Department of Energy (DOE).
There are several ways to reduce the total amount of flow:
Make sure your pumps are a good fit by:
If your pump is going too fast, you’re probably wasting energy. Consider:
Replace existing pumps and pump system components with newer, more efficient models. An estimated 15 percent of pumps are more than 20 years old. These pumps are less efficient than newer models and processes change over time (10 to 25 percent savings).
As with any equipment, pumps must be properly maintained for maximum efficiency. Make sure you:
Pumps can also act as turbines, recovering pressure energy that would otherwise be wasted.
By monitoring and controlling your pumps from a single location, immediate detection of problems is possible, enabling quick intervention and repair. Collected system data can be used for water modeling and energy use optimization, predictive maintenance, as well as seasonal flow and weather adjustments.
Effectively managing collection and distribution activities is vital to efficient system operation. Continuous monitoring of remote systems will help identify overflow situations or possible ground contamination. Features to look for include:
Unnecessary friction in the fluid system can increase energy use. Controlling friction resulting from pipe sizing or roughness in an existing system is nearly impossible. However, operators can improve friction inefficiencies caused by system components, unnecessary flow paths or high flow rates. Throttled valves in particular are often associated with friction losses. Measurements can be taken to determine efficiency loss through friction.