Energy-efficient pumping systems

Energy-efficient pumping systems

Xylem’s Gavin Westworth has developed an index that could revolutionize the diagnostic aspect of pumping systems. His formula can quickly be used to determine whether a system is operating efficiently.

“I’ve been in the pumping industry for more than 40 years and still find it satisfying to analyze the elements of a pumping system to ensure they all work efficiently together,” says Gavin Westworth in his warm, Scottish accent. As more than 20 percent of global energy is used for pumping and the cost of energy is ever increasing, Westworth knows it is important that these systems are set up and operated well.

As Energy Manager for Xylem, Westworth is well versed in running energy audits for clients – seeing where their systems are working efficiently, and where they are not. “Most recently I’ve been looking at wastewater pumping systems, where opportunities to improve efficiency and reliability are all around,” he says.

“But if you’re talking to a water company about energy audits, and they have 500–1,000 pumping stations,” says Westworth, “how do you identify which stations need attention without incurring a massive investigative cost?”

This is why he created the formula that is now known as the Westworth-Flygt Pumping Systems Efficiency Index.

A tool for initial assessments

The index is a “first-pass” assessment. The input data is basic information that it should be easy for the client to gather. It can be a snapshot of information taken at a specific point or it can be data gathered over a longer period.

“My formula tells me quickly if the system is not operating efficiently, but doesn’t tell me why,” says Westworth. “It puts the system into a broad category of very poor/poor/not good/good/excellent, and thus if a closer look is needed. If so, we’d go to the site and carry out an in-depth investigation.”

The index can be used on any pumping system – clean or dirty liquids, and any number of pumps. It just looks at what the system delivers and how much energy or power it uses.

Westworth says he’s surprised that no one has created anything like this before. “I think the index is really common sense. It took me a couple of hours to write the formula, and I’ve been using it for two years now.” 

Useful to the entire industry

Although the solution came easily to Westworth, others in the industry had been looking for a similar solution. The UK’s Department for Environment, Food and Rural Affairs (DEFRA) had identified wastewater-pumping systems as an area where energy improvements could and should be made, and that there was a need for a measurement tool. The intention was to invite tenders from universities and companies to develop it.

When Westworth heard about this through his colleague Bob Went, he said: “Hold a minute Bob, I’ve got this.”

What followed was a meeting with DEFRA and, as Westworth describes it, “there were some gasps of astonishment around the table when they realized that this was exactly what they needed, but I’d never publicized it.”

Since then, Westworth has been invited to present his index at conferences, and many water companies have asked him to speak to their energy teams. And he of course still uses the index with Xylem’s own clients. The index is also being promoted by the British Pump Manufacturing Association in the UK and Europump in Europe, and it may become part of the ISO14414 standard for Energy-Efficiency Testing of Pumping Systems.

“It’s really very satisfying,” says Westworth. “The best part is that it shows Xylem in a different light with clients. When I show them the index, and how it can improve pumping systems, they no longer see us as a product and service supplier, but rather as a company trying to help them reduce costs and energy consumption. You get a real sense of achievement when big savings are identified.”

Read more about Xylem’s energy audits here

kirjoittaja Jane Christie-Smith