Opportunity knocks? 27 September 2014

While the temptation is understandably to tackle energy-saving projects piecemeal on the shopfloor, taking a holistic approach will reap far bigger rewards. Brian Tinham reports

It is an undeniable truth that energy represents one of the biggest costs for almost any plant or factory. Ergo, significant savings could be made by employing modern technology and better processes where, by modern standards, waste is now evident. True, yes, but the fact is we are where we are – mostly with legacy plants, established processes and production lines designed, equipped and commissioned long before energy (and hence also emissions) were the burning issues they are today.

That makes changing them potentially very expensive, certainly in the short term. Just as important, given the inevitable complexity and inter-dependence of plant and factory operations, it also makes serious energy-saving projects difficult to define, hard to prioritise and a logistical nightmare to execute. No wonder, then, that the vast majority of project teams go for the 'low hanging fruit', picking off relatively easy wins piecemeal, without too much reference to the bigger picture.

To an extent, that's fine: worthwhile projects are sanctioned; the payback is often rapid; energy, costs and emissions are reduced; and everybody's happy. The obvious point, however, is that the outcome might have been orders of magnitude higher – meaning way better competitiveness and/or profitability – had senior management been committed, engaged and seeking out orchestrated energy savings factory-wide.

So, how might you go about the latter? Energy professionals will already be on the case with the ISO 50001 energy management standard, which generalises best in class systems and a structured approach to improvement from top to bottom, aimed at any business. No one pretends that adopting the international standard is a quick fix – it's anything but and there are plenty of management consultants making a good living out of training courses and business transformation hand-holding. But if you're after an inclusive, independent roadmap of appropriate systems, ISO 50001 is a good as it gets.

Meanwhile, energy specialists should also be up to speed with ESOS (Energy Savings Opportunity Scheme) – the UK's response to Article Eight of the European Energy Efficiency Directive. This legislation, announced on 26 June 2014, requires all 'large enterprises' (those with turnovers in excess of €50 million) to carry out energy efficiency audits before 5 December 2015. And whether or not your company is one of the 7,000 estimated to fall into that bracket, the fact that the government reckons ESOS will help organisations cut energy costs by £250 million by 2016, and £1.6 billion by 2030 (the Carbon Trust suggests three times those numbers) tells you something.

Apparently, the thinking and practice behind ESOS have a lot to offer. Energy management consultancy CMR advises that these centre on four-yearly audits that not only measure consumption but also identify cost-effective energy saving opportunities. The firm also explains that, if businesses are not already ISO 50001 certified, they have a choice of new ESOS-compliant energy audits (verified by accredited lead auditors on the Environment Agency register), Green Deal Assessments and Display Energy Certificates.

"DECC's [Department of Energy and Climate Change] efforts to simplify compliance and make use of existing schemes provides organisations with a real opportunity to meet their own wider goals, while complying with ESOS," comments Chris Doubleday, energy and water consultant at CMR. "Carefully considered, ESOS represents an excellent opportunity for organisations to stimulate a step change improvement in energy efficiency, laying the foundations for a more resilient and sustainable future."

Anthony Mayall, managing director of NIFES (part of Inenco, which has created an independent ESOS Hub) agrees, but warns that the clock is ticking: "The December 2015 deadline for ESOS may seem a long way off, but it's a mistake to get complacent," he says. "Act quickly to undertake the audit and implement the energy-saving recommendations, and you'll see in-year benefit, making the process at least budget-neutral." And he adds that companies waiting until just before the deadline risk overpaying for their ESOS audits or failing to comply on time.

Why? Because the 7,000-plus organisations in scope can ultimately only be served by around 500 recognised auditors. So to an extent, it's first come, first served. What's more, choosing the right auditor, one with relevant industrial experience, is critical to maximising on ESOS – turning what might otherwise be another carbon tax into a real opportunity for financial transformation.

"Sector experience is crucial," agrees Mayall. "Industrial organisations will be aware of the potential for disruption to operations. Each production site needs to be considered – if they are not identical, they are classed as different site types and need auditing. But, with quick action and the right support, downtime can be minimised and output won't be compromised."

Be warned, though: Stephen Barker, head of energy efficiency and environmental care at Siemens, worries that the qualifications for those chosen 500 auditors were too lax. "I worry that ESOS could easily turn into ESMOS – Energy Saving Missed Opportunity Scheme," he cautions. "The requirements for auditors are too weak: if you're considering a complex manufacturing or process plant, you need a lot of knowledge, expertise and experience, and that isn't reflected in the auditors' qualifications."

Furthermore, Barker points out that too many mandated policies in the end drive a culture of compliance, not a culture of good practice. "There's a big difference. Some businesses will go the ISO 50001 route because it gives them ESOS. But if they don't embrace the spirit of energy management and implement the recommendations, they're not going to get the benefits." And he points to anecdotal evidence from a database of companies where energy audits have been carried out, which shows that organisations adopting good practices see, on average, four times the savings of those that do not.

"The vast majority of plants and factories could achieve 15—20% reduction in energy consumption, and the good news is that, typically, that is achievable with measures that pay back in under three years," asserts Barker. "But there are also operational efficiencies to be had, not just energy and resource efficiencies. Improving productivity, reducing downtime and reducing maintenance [time and cost] go hand in hand with this kind of approach."

His recommendation: choose your site auditors carefully and ensure that the output absolutely includes an evaluated efficiency improvement strategy for the next five years. "We like to think of this as a collaborative exercise, working with the guys on site who know the process detail better than anyone else. We also like to think that adding an external set of eyes and appropriate efficiency improvement expertise to site knowledge is a winning combination."

As for how, Barker recommends installing automatic monitoring and targeting systems – not just metering systems – covering large machines and plant consuming significant energy. He also suggests sensibly targeted monitoring around production lines to get some detail – including using built-in variable speed drive functionality.

"Do this properly and it's the number one technology you can install. It will quickly identify the low-cost and no-cost savings that would otherwise be missed." Examples, he says, might include operations running out of sequence and devices left running that should be switched off or down.

And he adds that taking this to the next level, with energy and resource analytics (including electricity, gas, water, steam and compressed air), reveals not only the real current cost of operations, but the cost for specific products, sequences etc. "The energy consumption signature tells you a lot about what's going on around the plant itself," he says.

Now, why wouldn't you want to know that?

Newtown Plastics drives down motor costs

From 1 January 2015, Regulation (EC) 640/2009 – which implements the Ecodesign Directive 2005/32/EC – will require all new electric motors sold in the EU to meet or exceed the IE3 premium energy efficiency standard. The ruling applies to all motors in the range 7.5—375kW designed for continuous operation at a constant load. Alternatively, IE2 motors can be used, but only if they are governed by variable speed drives (VSDs).

It's all about reducing the environmental impact of the vast estate of comparatively inefficient, often oversized and almost entirely outdated industrial electric motors running in plants and factories everywhere.

Clearly, there will be cost implications for plants needing to replace ageing and worn motors since they will probably be prevented from purchasing like for like. And note that, for those seeking workarounds, there are limits to allowed repairs, with consultants warning of caveats under the directive.

However, quite apart from their superior environmental performance, higher efficiency motors and those running under VSD control also save energy and can improve product quality and throughput. Indeed, the overwhelming evidence is clear that – assuming sensible energy audits to prioritise projects – many replacements pay back within a matter of months and then continue saving throughout their working lives.

And that's not just the case on large-scale, energy-intensive plants. For example, Newtown Plastics, which recently retrofitted an ABB VSD to just one of its injection moulding machines, is now saving nearly £2,000 a year. Energy consultant Wayne Trematick says the mid Wales plastic components manufacturer installed the unit following an audit by ABB and City Electrical Factors (CEF). "The energy appraisal showed the company could save £1,963 on energy costs, with an 18 months payback," he explains.

Newtown Plastics director Simon Church says that one of its injection moulders, equipped with an 18.5kW motor and running a long cycle time, was identified as a prime candidate. "We have 14 machines but this one was selected because it ... operates for 40 weeks a year making perfume display cases and requires a long cooling cycle. During this time, the hydraulic motor was not doing any work but was still running at full speed, so it was an obvious choice."

Note that Church says there are several other bigger injection moulders, but that these all operate with faster cycle times, so retrofitting VSD control was less attractive. Just as important, though, looking at the refitted machine, he explains that not only is motor speed now properly controlled, but also not using pressure transducer signals, but instead the drive's internal load measurements, which determine whether the pump is doing useful work or recycling back to the tank.

When the pump is recirculating – while the part is being cooled – motor speed drops to 50%. Off-load power has hence been reduced from 7kW to 3.7kW. Says Church: "I have been very impressed with the savings. We have a compressor with a VSD and our new machines come equipped with servo drives so we know about [drives] and can't fault them."

Compressed air energy-saving opportunities
Compressed air systems are increasingly being seen by consultants as ripe for energy-saving measures. Whereas in the past, most pundits saw other factory and plant utilities – primarily electricity and steam generation/distribution – as the priorities, newer technologies and falling capital costs are changing that perspective.

That said, compressor projects are not for everyone, so prudence dictates an energy audit, assisted by a data logging exercise to assess compressed air requirements and the efficiency of the existing system. How far should you go? Andy Jones, managing director of compressor manufacturer Mattei, suggests that it's worth looking at ISO 11011:2013, which sets out best practice for an assessment.

He also makes the point that, while sometimes the main recommendation might entail investing in a new compressor, for the most part incremental, affordable changes can have a big impact. "Savings can often be made through simple alterations to the system itself. For example, relocating the compressor so that the air being drawn in is as cool and clean as possible, and ensuring that pipework is suitably sized, has been designed with minimal bends and distance, and is leak-free, can all pay dividends in terms of saving energy. Adding heat recovery – if appropriate – can also be beneficial," he explains.

That said, he concedes that sometimes a new compressor will be the best route to optimum savings, taking into account lifecycle costs. "As an example, one of our customers in the food manufacturing sector can expect to save £150,000 over five years as a result of a system upgrade and the installation of Mattei Maxima 75 compressors."

His view: getting this right is about seeking advice from compressor specialists. Above all, he says, don't waste the opportunity by simply replacing like-for-like.

Brian Tinham

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