How pump retrofits boost profitability and efficiency in ageing power plants

Amidst this changing environment, operators still have control over one key factor: plant efficiency.

Extreme heat is pushing cooling demand to new highs, prompting countries to increasingly rely on fossil fuel-based power sources to keep the grids stable and flexible. 

Countries are turning to sources like gas to meet soaring demand and fill critical gaps in the energy mix. Last summer, powerful heatwaves in India drove a 32% increase in gas demand between May and July, according to the IEA. 

In Southeast Asia, El Niño-induced droughts sharply reduced hydropower availability in Thailand and Vietnam, forcing grid operators to lean more heavily on gas-fired generation. In Singapore, record peak demand in May 2024 highlighted the importance of gas turbines in maintaining reliability, whilst in Australia, low wind speeds during the summer of 2023 triggered heavier reliance on flexible gas units to balance the system. 

Despite playing a critical role in grid balancing, many thermal power generators are faced with an uncertain future. A mixture of environmental pressures, geopolitical tensions, a competitive global gas market, and increasing renewable power generation are presenting increased risks and opportunities. 

In addition, over the past decade, many thermal power plants have been required to switch from baseload to backup generation where flexible operation requires faster and more frequent start-ups to respond to fluctuating grid demand with an enhanced focus on competitiveness and profitability.  

Power plants and oversized pumps
Amidst this changing environment, operators still have control over one key factor: plant efficiency. For those plants built in the 1990s and 2000s, the possible energy efficiency gains may be especially large due to improved equipment and plant designs. In earlier plant designs, equipment such as pumps was oversized right from the start. 

For example, safety regulations require a boiler to be pressure tested periodically beyond their typical operating limits to ensure the correct function of all protective equipment. The corresponding pumps must be deliberately oversized to facilitate this. As a result, more than 99% of the time, those pumps are throttled, leading to significant energy waste. In other cases, pumps have become oversized due to changing operating conditions, and most have deviated from their best efficiency points due to age-related deterioration. 

Energy inefficiency costs hundreds of thousands of dollars each year
According to recent research, nearly 40% of the pumps in fossil-fuelled power plants ran outside of their preferred operating range for more than 80% of the time. It is estimated that these inefficiencies lead to hundreds of thousands of dollars of energy wasted with significant carbon emissions each year, depending on pump type and operation regime. 

BB3, BB4, and BB5 pumps offer the greatest potential for energy efficiency improvements. These pumps are the backbone of many mid-sized power plants, with over 50% of those analysed capable of saving $50,000 or more annually. 

Many operators have put energy efficiency projects on hold in order to prioritise baseload power. It can be difficult to schedule additional projects when a typical shutdown is already tightly choreographed with people and projects all needing the same resources from cranes to workshop space. However, when it comes to retrofitting pumps to improve energy efficiency, many implementations can be completed while the plant is operating. 

Implementing efficiency projects while maintaining uptime
When implementing energy efficiency improvements in an operating plant, one key concern is whether the work will disrupt production. Creating peace of mind will look different for every operator, but there are several potential solutions that can start way before the pump is taken out of action. 

It is possible, for example, to purchase raw materials and pre-machine parts before the pump arrives in the workshop. Access to the spares inventory allows for a plan B, if a pump is in a much worse state than anticipated. 

Additionally, 3D printing spare parts is also increasingly common, especially in many parts of Asia. This technology is significantly faster than traditional casting. Similarly, spare parts manufacturing can be substantially accelerated by having a library of patterns to support reverse engineering.

When it comes to the implementation itself, where there is a duty and standby pump, the standby pump can be retrofitted first, tested, and then changed over, to allow for the modification of the duty pump. Alternatively, if one of the pumps is unreliable, it can be swapped out for a spare to allow the original to be modified and for production to continue. 

Unlocking efficiency gains through pump retrofits
Whilst gas-fired electricity generation will continue to play a critical role in grid balancing, the landscape is becoming increasingly competitive, putting pressure on operators to find new ways to retain profitability. Improving pump efficiency is a huge untapped opportunity within the power sector. With many power plant pumps found to be running outside of their preferred operating range, hundreds of thousands of dollars and hundreds of tons of carbon could be saved a year with a bespoke retrofit solution. 

A wide range of retrofit projects across Asia-Pacific has helped operators improve efficiency and reliability whilst keeping costs under control.

For instance, in China, power plants are pressured to achieve key metrics as part of the national decarbonisation plan  where carbon emission intensity needs to be reduced to 820g/kWh. In 2024, a 125MW coal-fired power plant based in Western China embarked on a proactive carbon reduction exercise. 

The boiler-feed pump in one of its units was primed for optimisation with a declined efficiency rating of 71%. By employing a technical retrofit with a combination of hydraulic re-rate, reducing clearances and using ASME-standard chromium steel to enhance wear resistance, the pump achieved an improved efficiency of 78% which helped the power plant to reduce its power consumption and carbon emissions by 8.6%.

In India, older power plants built before the 2000s were not designed to meet the dynamic demands of modern grid balancing. 

As newer, more efficient supercritical power plants began to take a larger share of generation, legacy plants faced increasing inefficiencies due to oversized pumps. The pumps originally sized for higher loads became disproportionately large for reduced operational demands. 

For a North-western power plant, in a retrofitting project focusing on hydraulic optimisation, a significant reduction in absorbed power-344kW per pump was delivered. This translated into an estimated annual cost savings of approximately $100,000, highlighting the value of targeted retrofits for ageing plants.