Improving Performance #02

Significant improvement in energy performance can often be achieved with little or sometimes no capital outlay being required whatsoever. For example, when the last person out at night turns off the lights how many of us are lulled into a false sense of security into thinking that the energy consumption of our offices or factory also switches off for the night?

Energy Performance Monitoring

We always fit energy loggers to record out-of-hours electricity consumption as part of the energy review carried out to implement the ISO 50001 Energy Management System.

The results, as might be imagined, are very mixed but on several occasions the logging equipment revealed some alarming instances where the non-working hours demands when the building(s) are unoccupied were not massively different from the working hours demands.

The two examples that follow were obtained from real world energy audits carried out as part of our lead assessor activities during the first phase of the UK Energy Saving Opportunity Scheme (ESOS).

Pharmaceutical Factory

A pharmaceutical company in Manchester occupied two factories that produced nasal sprays on behalf of a multinational Corporation. The heating in the main production area comprised of direct gas fired warm air heaters controlled from a central location.

The gas meter serving the factory had recently been upgraded to a ‘smart-meter’ that permitted the client to view their gas consumption over any period selected on their web-based software.

The chart reprinted below shows the gas consumption for a typical period that spans productive and non-productive hours and demonstrates that significant gas is being consumed during times when the factory is closed i.e. at night time and over the weekend.

By extending the kWh result by the number of non-productive hours per year and then multiplying the total kWh by the current price of gas paid by the company the estimated cost of heating the factory during non-productive time amounted to an eye-watering £20,845 per annum.

Nasal Spray Factory Gas Consumption: Unoccupied Demands Highlighted

Upon close examination of the heating controls it became apparent that the heating function was permanently set to ‘ON’ as opposed to ‘AUTO’. Our investigations revealed that the heating system was being commanded to maintain a set-point temperature of 25.5 degrees Celsius in the production area regardless of whether the factory was in production mode or not.

Gas Heating Controls Permanently Set to ‘ON’ rather than ‘AUTO’.

Herbal Factory

An unexpected result was obtained when the energy monitoring equipment recorded the 24-hour electrical energy consumption of the herbal factory. The energy logger registered a spike in consumption that commenced at approximately midnight and then mysteriously disappeared at about 2am.

The anomalous result was reported to the client and following a lengthy investigation, it was discovered that a split air conditioning unit serving the offices was being commanded to switch on for about 2-hours after midnight. The local controller was duly adjusted to take account of the correct occupancy times for the factory offices and the spike in consumption has now been eliminated.

And For The Good News…

Keeping track of energy consumption also reassuringly confirms when things are going as expected i.e. for equipment to only consume energy during the operating cycle and no other times. In the following example, we monitored the consumption of an industrial dishwashing machine in the main production area for a 24-hour period.

The energy logger established that no energy was being consumed by the equipment until it was required by the operators to perform a cleaning cycle and once completed the energy consumption fell back to zero.

Energy Performance Monitoring

The value of regular monitoring of both electricity and fossil fuel consumption is difficult to overstate enabling irregularities such as the spurious switching on of equipment and systems to be readily identified and remedial action taken if determined necessary.


The findings of our energy investigations illustrate that significant improvement in energy performance can often be achieved with little or sometimes no capital outlay being required whatsoever.

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