It’s not only oversizing that impacts performance. Changes in operating conditions, system design mismatches, and age-related wear can all push pumps away from their best efficiency point. Even well-sized pumps can become inefficient over time if hydraulics deteriorate, duty points shift or the surrounding system changes.

Recent research conducted by Sulzer shows that nearly 40% of pumps in fossil-fuelled power plants now run outside their preferred operating range more than 80% of the time. It is estimated that these inefficiencies could lead to hundreds of thousands of dollars of energy wasted with significant carbon emissions each year, depending on pump type and operation regime.

“Just because a pump hasn’t failed doesn’t mean it’s performing,” Irlam explains. “We see reliable equipment drawing huge amounts of unnecessary power, it’s a slow leak that adds up fast.”

Big gains ahead, especially for BB3 pumps

The energy efficiency improvement potential is especially high for BB3 pumps – the workhorse of many mid-sized power plants. Sulzer’s analysis found that over 50% of those analysed could save $50,000 or more annually through retrofits alone.

In today’s volatile power market, these gains can make a real difference, particularly for plants operating under tighter margins or more flexible load regimes. Still, some operators hesitate, assuming energy efficiency upgrades mean lengthy downtime or project risk. But our approach is designed for real-world constraints, including keeping plants online.

Retrofit gains without shutdown pain

Efficiency upgrades don’t have to wait for an outage or planned shutdown. With proper planning, most retrofits can be completed during normal operations using standby pumps, advanced prep and modern manufacturing techniques.

“We work backwards from what peace of mind looks like for each plant,” says Irlam. “That might mean pre-machining parts, building in spares contingencies or using 3D printing to accelerate delivery - all before the pump even comes out.”

Onsite execution is just as flexible. If a duty and standby pump setup is available, the standby pump is upgraded first, tested and swapped in before the duty pump is touched. Where pumps are unreliable, they can be rotated with spares, keeping operations online while modifications are made.

Real-world uplift: More output, less disruption

At a power station in the East of England, operators faced a choice. Their hot gas path components had reached the end-of-life and the replacement gas turbine brought a significantly higher exhaust temperature. That created an opportunity to recover more energy from the steam cycle but only if the boiler feed pumps could handle it. Rather than replace them, the plant partnered with Sulzer to retrofit the existing pumps.

Sulzer engineered a bespoke hydraulic from first principles, with a larger diameter to boost performance. Stage casings were modified, and custom wear parts were added. All other major components (and the existing pump footprint) were retained.