David Horton, head of project delivery and asset management at Shell Energy UK, explores the connection between energy use and water and how major energy users can improve efficiencies, build energy resilience, manage costs and decarbonise operations.
Energy efficiency is an increasingly critical part of optimising business performance, maintaining market competitiveness and meeting tightening legislation. When it comes to energy intensive businesses, such as data centres, delivering year-on-year improvements can become a high-pressure task.
Tackling day-to-day energy efficiency challenges is often overlooked, particularly the connection between energy use and water dependency.
Within the energy system, water is essential for generating electricity, as well as cooling industrial processes and running heating systems. Energy is needed to acquire, treat, and distribute water, and therefore the two resources go hand in hand. Recognising their interdependence is the first step in developing sustainable practices that benefit both the environment and businesses’ bottom lines.1
Many industries, from food processing and glass manufacturing to metals production and data storage, use water as part of their operations. There are ways to improve efficiency at several key points, whether making the efficiencies in how water is moved around site, how it is heated, how heat can be captured and re-used on site, and whether grey water (clean wastewater from industrial processes) is recycled to help ensure optimal efficiency.2
According to the British Pump Manufacturers’ Association (BPMA), the operation of water pumps and their associated systems accounts for around 20% of the world’s entire electrical energy consumption. In some high-use industrial applications, this can be as much as 25-50% of the total electrical energy usage. Pumps are the single largest user of electricity within industry across the European continent, consuming over 300 terawatt-hours per anum of electricity, which in turn accounts for over 65 metric tonnes of CO₂ emissions.3
Analysing pumps for potential efficiencies can therefore be a valuable exercise, especially as, in many industries, they may have been over-specified to take account of potential changes in demand or use. In fact, according to the BPMA, the majority of pump systems operating today were not originally designed with energy conservation as a major consideration. As a result, 80% of pumps installed across Europe are said to be up to 30% oversized.4
In practice many pumps often use far too much energy for their required duty and there is huge potential to save energy if these pumps are properly sized, operated and maintained. The BPMA predicts that if pump systems are initially designed with energy use in mind and optimised for efficiency, a saving up to 50% in electrical energy can be achieved.
In essence, it is important to know as much about your pump system as possible and to create a pressure/flow profile, as the energy required is directly related to flow and pressure specifications.
Another factor to consider is that up to two-thirds of total energy consumption is used to power electric motors – an integral part of any pump system. The overall cost associated throughout their entire life span can be broken down as follows; 5% accounts for the initial purchase/installation costs, 10% for ongoing maintenance and a massive 85% for the energy used to run them.
The use of variable speed drives (VSDs) also extends asset lifespans and reduces maintenance schedules. Older non-variable speed drives work constantly at 100%. By embracing a VSD, you can reduce the load and extend the life by reducing mechanical stress on the motor. In addition, they also reduce noise generation and are said to be far more efficient overall.5
There are two main considerations when it comes to motor efficiency. Firstly, modern motor designs are already able to reduce energy consumption by as much as 30%. The second is the opportunity offered by variable speed drives. Put simply, many pumps and motors are constantly operated at full power, irrespective of process needs, but the addition of VSDs can make sure demand aligns to real world requirements. The BPMA highlights that their introduction across Europe’s installed base has the potential for significant energy savings. This, in turn, can increase the profitability of any business.
Ultimately, ensuring that the pump and its operation are closely matched to system requirements can minimise energy wastage. There is no point in fitting a pump with a high efficiency rating, if it is over specified from the start. Similarly, if energy efficient pumps are fitted, but can’t be adjusted in line with demand, energy is lost.6
Beyond pumps, ensuring that pipework has no leaks, is well insulated and that temperatures are set at the optimum for the job required are critical. There are many ways to ensure that water use, both hot and cold, is optimised for energy efficiency. Constraints on water supply are also prompting businesses to look at water re-use and recycling, which again requires energy use and should encourage the same scrutiny to ensure equipment is fit for purpose, used efficiently and well maintained to optimise efficiency at all times.
The decarbonisation agenda is driving innovation in processes, with greater emphasis on energy efficiency as new products are developed. This is an opportunity for businesses as they double down on ways to deliver improved sustainability performance across the board.
References
www.ciwem.org/news/water-efficiency-net-zero
www.iea.org/commentaries/if-the-energy-sector-is-to-tackle-climate-change-it-must-also-think-about-water
Energy efficiency –<br> are attitudes changing? » Latest News – BPMA
www.bpma.org.uk/news-article/638888250dba6/Optimising-pump-systems-to-save-electrical-energy
Variable Speed Drives – an overview | ScienceDirect Topics
www.bpma.org.uk/news-article/5f918cd469499/The-Pump-Industryrsquos-ltbrgt25-Year-Drive-for-Energy-Efficiency
