Plant & Works Engineering
A golden opportunity
Published:  06 March, 2015

Organisations that qualify for the ESOS (Energy Savings Opportunity Scheme) that are not fully covered by ISO 50001 must now carry out assessments every four years to determine their energy use and identify cost-effective energy saving measures. The new requirements are a golden opportunity to help reduce energy use, carbon emissions and costs, and can help to ensure that compressed air systems operate more efficiently than ever before, says Andy Jones, managing director at Mattei.

As we welcomed in the New Year, we also ushered in a new set of regulations to help large organisations reduce their energy consumption through proper assessment and analysis of usage. While many large businesses have already adopted processes to reduce their energy use, carbon emissions and costs, the Government’s new Energy Savings Opportunity Scheme (ESOS) seeks to plug the gaps in UK industry to ensure that efficiency is front of mind for every major consumer of energy.

The ESOS regulations will help the UK to comply with the EU Energy Efficiency Directive, and are applicable to any large organisation which carries out a trade or business and employs at least 250 people. Organisations which employ less than 250 people but have an annual turnover in excess of €50m and an annual balance sheet total of over €43m will also need to comply, unless they are fully covered by ISO 50001.

To meet the requirements of the ESOS regulations, a specially appointed ‘lead energy assessor’ will need to conduct an assessment to measure the organisation’s total energy consumption for its buildings, industrial processes and transport. This assessment can take into account energy partly covered by ISO 50001, Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) to minimise the duplication of reporting and analysis.

Once the total energy consumption has been calculated, the organisation will need to identify areas of significant energy consumption – the assets and activities that account for at least 90 per cent of the total energy used. For companies operating factories and processing plants, this will most likely include compressed air.

Compressed air is often referred to as the UK industry’s fourth utility and is an essential part of many commercial and industrial processes. In fact, there are so many electrically driven compressors in use, they account for around 10 per cent of the total electricity consumed in the industrial sector.

Based on the assessment, organisations will need to identify energy efficiency recommendations for the activities and assets which consume most energy. These energy saving opportunities must be reasonably practical and cost-effective to implement and the recommendations should include the estimated costs and benefits they would bring.

Until now, end users have been under no obligation to carry out assessments of their compressed air systems, so energy audits, data logging exercises and leak detection surveys have been voluntary exercises. It’s therefore likely that the vast majority of organisations don’t know how much compressed air they use, or how much it costs them, or even if their compressors are actually appropriate for their production processes.

A thorough energy audit will highlight where there is scope for improving the efficiency of a compressed air system. We recommend regular energy audits for compressed air users, regardless of whether they’re needed for compliance or not, and welcome any regulations or legislation that can help to make compressed air systems more efficient.

There are many reasons why compressed air systems can be operating ineffectively. For example, incorrect sizing can easily cause inefficiencies in the system and increase running costs. We often find compressors rated at 10 bar and above working in a system that only requires six or seven bar pressure; this is a very inefficient way to operate a compressed air system, as every one bar increase in pressure increases energy consumption by approximately 7%.

Similarly, if the wrong type of compressor is specified, this too will increase energy consumption. While variable speed compressors are often seen as a key way to reduce the cost of producing compressed air, offering typical savings of 30% or more, this type of compressor will only save energy if there are true variable peaks and troughs in the demand for air – and only when these variations fall within the efficient working band of the compressor.

Leaks are also a common problem affecting compressor efficiency. In many companies, more than 30% of air generated by a compressor is wasted through leaks – but a simple and cost-effective leak detection survey will highlight any problem areas quickly.

Whether a compressed air system is being assessed for ISO 50001, ESOS or for a general cost/carbon saving exercise, it is worth remembering that ISO 11011 (Compressed air – Energy efficiency – Assessment) is an international standard framework specifically created to audit compressed air systems. It was officially introduced in 2013 in response to the need for industry consistency in the way compressor energy consumption is measured and to standardise the recommended actions given to users.

Prior to ISO 11011, many compressed air equipment manufacturers and suppliers offered customers energy audits as part of their service offering, along with data logging exercises and leak detection surveys, but these varied greatly in quality and effectiveness in helping users to reduce their energy consumption. Under ISO 11011, individual manufacturers and suppliers should now all be offering similar advice and carrying out the same assessment and auditing procedures on a level playing field. So by choosing an ISO 11011 audit, compressed air users can be assured that it meets the accepted industry standard. This should also make it easier to decide what action to take from the recommendations provided.

While ESOS could be reviled as ‘more red tape’ for British businesses, in reality it is actually a good way of encouraging organisations to review their compressed air systems and make them much more efficient in operation. This benefits not only the bottom line and the environment, but also improves reliability and performance. And that can only be a positive outcome for UK industry.

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