Looking for Spirax Sarco products and services?

The Benefits of Steam System Optimisation

How Focusing on the Now is Crucial for Tomorrow

Engineer optimising steam system

Look back at the progress reports on climate change over the past few years, and you'll find little to celebrate. We know what's at stake; failing to limit our planet's rising temperature will have dire consequences for us all. Yet the swift action needed to reach our net zero goals isn't happening. If it's a "Race to Zero" we're in, then why does it feel less like a sprint, and more like a three-legged race?

Cast your mind back to early 2022. The world was recovering from a devasting pandemic, and economies were rebuilding. But if we thought things were on the mend, when it came to climate change, there was a downside. CO2 emissions from electricity and heat reached their highest-ever level, provoking the International Energy Agency (IEA) to issue a clear call to action. 

The world must now ensure that the global rebound in emissions in 2021 was a one-off – and that sustainable investments combined with the accelerated deployment of clean energy technologies will reduce CO2 emissions in 2022…¹

The gauntlet was thrown, and another year passed. One that saw aggression in Europe and a global energy crisis emerge. The impact on climate change aspirations was stark. Last March, the IEA reported, "Global carbon dioxide (CO2) emissions from energy combustion and industrial processes grew 0.9% or 321 Mt in 2022 to a new all-time high of 36.8 Gt." 

The best that could be said was that at least clean energy continued its rapid advance, without which "the growth in CO2 emissions would have been nearly three times as high."² 

Glass half-empty, or half-full?

From any standpoint, the outlook can seem discouraging. A little like getting a school report, time after time, that simply demands "must try harder". It doesn't help that we always seem to be looking back over our shoulders, at what might have been, instead of looking ahead with optimism and ambition. 

It's a classic example of the problem of scale. When faced with problems that are so much larger than our individual actions, there's a tendency to become demotivated. Feelings of helplessness can dominate, or, alternatively, we turn to technological optimism. 

You can see this at work with the visionary approaches to tackling climate change. Yes, we look forward to seeing green hydrogen being made widely available, to be able to remove carbon dioxide and lock it away for good, and welcome any ground-breaking processes that eliminate its production in the first place. 

Capturing our imaginations, they seem to offer promise when silver linings are in short supply. Innovation will always be key to dealing with the complexity and scale of the issues surrounding climate change. In time, they will become part of our everyday lives. However, we do not have time on our side. 

There are just seven years left to keep 1.5°C within reach

That was the conclusion of the Intergovernmental Panel on Climate Change's report earlier this year. A clarion call certainly, but, as the authors suggest, "Net zero CO2 emissions from the industrial sector are challenging but possible." 

Over its 2,000+ pages, the IPCC report scrutinises every aspect of the climate crisis. When it deals with reducing greenhouse gases (GHG) from the overall energy sector, it suggests that this, “requires major transitions, including a substantial reduction in overall fossil fuel use, the deployment of low-emission energy sources, switching to alternative energy carriers, and energy efficiency and conservation.”³ 

Echoing the IPCC's message, the Chief Executive of the Science Based Targets initiative (SBTi), Luiz Amaral pointed out that limiting global warming to 1.5°C requires a peak before 2025, reducing emissions by 43% by 2030, 60% by 2035 and reach net-zero in early 2050. 

It's not going to be easy, but with the right mindset, meaningful progress can be made towards a more sustainable future. 

Organizations with validated science-based targets have proven monumental reductions are possible - cutting scope 1 and 2 emissions by 12% on average year on year - greater than the 7.6% year on year reductions required to achieve the Paris Agreement’s 1.5°C goal.⁴

Why optimising for efficiency isn’t old news…

It's encouraging to see the progress being made by the 2,731 companies with science-based targets, of which we're one. By focusing on the now and refusing to allow the status quo to control the narrative, progress is being made. Companies will have different ways of achieving their goals, but a common theme is efficiency. 

That was one of the key messages from the Biden-Harris administration's Industrial Decarbonization Roadmap, published in September last year. As the country with the second-largest CO2 emissions in the world, any progress in detailing how it aims to tackle this is welcome. Recognising that 30% of US energy-related CO2 emissions originate from industry, it focuses on the way forward for five of the highest CO2-emitting industries: petroleum refining, chemicals, iron and steel, cement, and the food and beverage sectors. 

Of the four key technological pillars identified, it concludes: 

"Energy efficiency is a foundational, crosscutting decarbonization strategy and is the most cost-effective option for GHG emission reductions in the near term.”⁵ 

Not only the American government saw efficiency as part of the blueprint to averting climate disaster. The IEA released their tracking report on Energy Efficiency in the same month, emphasising: 

“Energy efficiency is the single largest measure to avoid energy demand in the Net Zero Emissions by 2050 Scenario, along with the closely related measures of electrification, behavioural change, digitalisation and material efficiency.”⁶ 

You might think that nothing could be more businesslike than increasing efficiency. That it's on every day's agenda. Then why are we constantly being reminded of its importance? 

…and why steam system optimisation remains a priority

Widely recognised by many industries as being an essential, enduring part of their processes, steam is a naturally efficient source of thermal energy. That doesn't mean steam systems cannot be improved, but experience and expertise mean we do know how to go about that. 

There are a range of proven, cost-effective measures to improve a steam system. Why these are not universally adopted is down to a combination of factors, many of these not related to monetary obstacles. 

The first, and simplest reason is due to a lack of information and knowledge. Whilst recent high-level reports have pointed to efficiency as a first step towards decarbonisation, steam systems are complex, often unique to a particular industry, or even plant. Knowing where to optimise, how to go about it effectively, and understanding exactly what the benefits will be, require specialist help. 

A range of other factors combines to keep efficiency top of the “yet-to-do” list for many companies. Often a lack of financial resources makes it hard to adopt even measures which will pay for themselves in a short time (especially for small-medium enterprises). The absence of support from top management, uncertainty about new technologies and fear of production disruption, and lack of government incentives coupled with lack of enforcement for government regulations, all add to inaction. 

Beyond general barriers hindering efficiency improvements, steam systems have their own specific set of difficulties to overcome. Traditionally, many companies have focused on boilers, not the entire steam system that includes steam generation (boilers), distribution, recovery systems, and how steam is used. 

Although system optimization might be more difficult than changing a piece of equipment since it requires a more holistic knowledge and assessment of the system, it will often yield much greater energy saving compared to replacing a single component with a more efficient one.⁷

And, if simply replacing a boiler with a more energy-efficient one might seem to make sense, it doesn't necessarily mean the whole industrial steam system will be more efficient. Under- or over-estimating steam demand, mismanagement of the system, and running the system below optimal efficiency are common factors in reducing overall efficiency. 

Evaluating steam system optimisation

Almost a decade ago, the United Nations Industrial Development Organization (UNIDO) report looked at the energy efficiency potentials for industrial steam systems.⁷ The aim was to demonstrate what efficiency measures were cost-effective and estimate their value. China was chosen as the test case. 

Seven steam experts from the US, Europe, and China were consulted to determine which common energy efficiency measures should be included, their energy savings, and the cost of implementing them. 

Unlike many countries, China's energy consumption pattern is dominated by the industrial sector. In 2019, manufacturing accounted for about 55% of China’s total energy consumption, and 59.6% of the manufacturing sector’s energy came from coal.⁸ 

Agreeing on nine technically feasible measures, the experts found all but two would be cost-effective, potentially leading to an annual CO2 emission reduction of 201.23 MtCO2. Taking all the measures into account would result in a total technical fuel savings potential of around 26% of the total fuel used to generate steam.

That fuel-saving was greater than the primary energy use of over 160 countries in the world. 

This table lists the nine steam systems efficiency measures, with selected values: 

Cumulative annual fuel saving and CO₂ emission reduction, percentage efficiency improvement, and lifetime potential for industrial steam systems efficiency measures in China ranked by their final CCE (cost of conserved energy)

  Typical % improvement in energy efficiency over low efficiency practice   Cumulative annual fuel saving potential in industry (PJ/y)  Cumulative annual CO₂ emissions reduction potential from industry (ktCO2/y)  Typical life of measure (years)  
1: Excess air management: tune existing positioning control (or simple control)   5.0% 348  34,177  0.5 
2: Combustion optimization 3.5% 572  56,227  12 
3: Optimization of insulation of steam piping, valves, fittings and vessels 5.0%  868  85,368  10 
4: Optimization of boiler blowdown and recovery of heat from boiler blowdown 2.8% 1,025  100,769  12 
5: Implementation of an effective steam trap maintenance programme 2.2% 1,140  112,049 
6: Optimization of condensate recovery
4.1% 1,346  132,304  12 
7: Flue gas thermal energy recovery (Economizer and/or air heater)
7.4% 1,687  165,817  16 
8: Flash-steam recovery
3.9% 1,851  181,953  10 
9: Loss on ignition (LOI) optimization  5.0% 2,047  201,231  10 

Think back to that seven-year deadline to make real progress towards net zero, and the lifespan of these measures shows how optimising steam systems can make a real difference. Whilst any one improvement would clearly have an impact, it's when the entire system is optimised that the benefits become significant. 

The majority of these measures are suitable for all steam systems, whatever the means of generation. The main variable will clearly be the impact on CO2 emissions. 

Recognising the need for cleaner energy, Chinese President Xi Jinping has stated the country will be carbon neutral by 2060. It is already the world's largest investor in the clean energy transition, committing $266 billion in 2021, more than a third of the global total ($755 billion). 

But, with the average working life of a steam boiler being 30+ years, moving away from fossil fuels will take time. By focusing on the now, and ensuring all possible efficiency measures are being used, a reduction in emissions is within reach. 

Achieving effective optimisation in steam systems

Circling back to those energy statistics we covered at the beginning of this article, and the challenge ahead for reaching net zero targets, it is useful to see how generalisations around "efficiency" might actually translate into action. 

None of these measures are awaiting development. All are technically possible and, in most cases, cost-effective over a relatively short period of time. And, most importantly, they'll reap tangible benefits whilst the other, newer technologies are still in the early stages of their evolution. 

Since the UNIDO report was published, the potential for optimising steam systems has advanced too. Now, with digital transformation rapidly being adopted, our knowledge of exactly where optimisation will be most effective is far greater. It’s something the IPCC highlighted in their report this year: 

Digital technologies can contribute to mitigation of climate change and the achievement of several SDGs (high confidence). For example, sensors, internet of things, robotics, and artificial intelligence can improve energy management in all sectors, increase energy efficiency, and promote the adoption of many low-emission technologies, including decentralised renewable energy, while creating economic opportunities (high confidence).³

Where efficiency is concerned, every country will have its top performers who tick every box, and its outliers, who have never given optimisation a second thought. The likelihood is, though, that room for improvement is always present. 

Using the latest digital insights, we've never had a better opportunity to gain a detailed technical assessment of the steam system's energy efficiency opportunities. Neither have the stakes ever been as high. Whilst it's possible we will see more disappointing news surrounding climate change, as Bill Gates once said, "bad news is a headline, and gradual improvement is not." 

¹: Global CO2 emissions rebounded to their highest level in history in 2021 - News - IEA 
²: Global CO2 emissions rose less than initially feared in 2022 as clean energy growth offset much of the impact of greater coal and oil use - News - IEA 
³: https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_FullReport.pdf 
⁴: IPCC releases ‘final warning’ to keep 1.5°C within reach - Science Based Targets 
⁵: DOE Industrial Decarbonization Roadmap | Department of Energy 
⁶: Energy Efficiency – Analysis - IEA 
⁷: Energy Efficiency Potentials in Industrial Steam Systems in China (unido.org)
When the study was written, coal-fired boilers accounted for around 80-85%, oil- and gas-fired boilers around 15%, and boilers that used other fuels (e.g. electricity, biomass, etc.) less than 5% of the total boiler capacity in China.
⁸: How Is China's Energy Footprint Changing? | ChinaPower Project (csis.org) 
⁹: China - Countries & Regions - IEA 

The Benefits of Steam System Optimisation

There are a range of proven, cost-effective measures to improve a steam system.